Umeå universitets logga

umu.sePublikationer
Ändra sökning
Avgränsa sökresultatet
12 1 - 50 av 51
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Träffar per sida
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sortering
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
Markera
Maxantalet träffar du kan exportera från sökgränssnittet är 250. Vid större uttag använd dig av utsökningar.
  • 1.
    Ambarki, Khalid
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Hallberg, Per
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Jóhannesson, Gauti
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Lindén, Christina
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Zarrinkoob, Laleh
    Umeå universitet, Medicinska fakulteten, Institutionen för farmakologi och klinisk neurovetenskap, Klinisk neurovetenskap.
    Wåhlin, Anders
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Birgander, Richard
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Diagnostisk radiologi.
    Malm, Jan
    Umeå universitet, Medicinska fakulteten, Institutionen för farmakologi och klinisk neurovetenskap, Klinisk neurovetenskap.
    Eklund, Anders
    Umeå universitet, Medicinska fakulteten, Institutionen för farmakologi och klinisk neurovetenskap, Klinisk neurovetenskap.
    Blood flow of ophthalmic artery in healthy individuals determined by phase-contrast magnetic resonance imaging2013Ingår i: Investigative Ophthalmology and Visual Science, ISSN 0146-0404, E-ISSN 1552-5783, Vol. 54, nr 4, s. 2738-2745Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    PURPOSE: Recent development of magnetic resonance imaging (MRI) offers new possibilities to assess ocular blood flow. This prospective study evaluates the feasibility of phase-contrast MRI (PCMRI) to measure flow rate in the ophthalmic artery (OA) and establish reference values in healthy young (HY) and elderly (HE) subjects.

    METHODS: Fifty HY subjects (28 females, 21-30 years of age) and 44 HE (23 females, 64-80 years of age) were scanned on a 3-Tesla MR system. The PCMRI sequence had a spatial resolution of 0.35 mm per pixel, with the measurement plan placed perpendicularly to the OA. Mean flow rate (Qmean), resistive index (RI), and arterial volume pulsatility of OA (ΔVmax) were measured from the flow rate curve. Accuracy of PCMRI measures was investigated using a vessel-phantom mimicking the diameter and the flow rate range of the human OA.

    RESULTS: Flow rate could be assessed in 97% of the OAs. Phantom investigations showed good agreement between the reference and PCMRI measurements with an error of <7%. No statistical difference was found in Qmean between HY and HE individuals (HY: mean ± SD = 10.37 ± 4.45 mL/min; HE: 10.81 ± 5.15 mL/min, P = 0.655). The mean of ΔVmax (HY: 18.70 ± 7.24 μL; HE: 26.27 ± 12.59 μL, P < 0.001) and RI (HY: 0.62 ± 0.08; HE: 0.67 ± 0.1, P = 0.012) were significantly different between HY and HE.

    CONCLUSIONS: This study demonstrated that the flow rate of OA can be quantified using PCMRI. There was an age difference in the pulsatility parameters; however, the mean flow rate appeared independent of age. The primary difference in flow curves between HE and HY was in the relaxation phase of the systolic peak.

  • 2. Aspberg, Johan
    et al.
    Heijl, Anders
    Jóhannesson, Gauti
    Umeå universitet, Medicinska fakulteten, Wallenberg centrum för molekylär medicin vid Umeå universitet (WCMM). Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Linden, Christina
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Andersson-Geimer, Sabina
    Bengtsson, Boel
    Intraocular Pressure Lowering Effect of Latanoprost as First-line Treatment for Glaucoma2018Ingår i: Journal of glaucoma, ISSN 1057-0829, E-ISSN 1536-481X, Vol. 27, nr 11, s. 976-980Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    PURPOSE: The purpose of this study was to assess the intraocular pressure (IOP) - reducing effect of latanoprost in treatment-naïve patients with newly detected open-angle glaucoma with no restriction of the level of untreated IOP.

    METHODS: Eighty-six patients (105 eyes) with a diagnosis of open-angle glaucoma received IOP-lowering therapy with latanoprost. The IOP reduction 1 and 3 months after initiation of treatment was recorded.

    RESULTS: Mean untreated IOP for all eyes was 26.2 mm Hg (ranging from 10 to 51 mm Hg). The mean pressure reduction was 7.9 mm Hg (28%), with equivalent average levels at 1 and 3 months. The reduction in IOP ranged from -2.3 to 25.3 mm Hg after 1 month, and from -1.3 to 33.3 mm Hg after 3 months. The pressure-lowering effect was considerably more pronounced in eyes with higher untreated IOP; the reduction increased by 0.55 mm Hg per mm Hg higher untreated IOP. Four eyes, with untreated IOP within statistically normal limits, had no or negative IOP-reduction. A regression model predicted that IOP reduction ended at untreated IOP≤16 mm Hg. Multiple regression analysis showed that an additional IOP-lowering effect of 1.28 mm Hg was achieved in eyes with pseudoexfoliation glaucoma.

    CONCLUSIONS: To the best of our knowledge, this paper is the first to report the IOP-reducing effect of latanoprost treatment at all untreated IOP levels in newly detected glaucoma patients. The effect was proportional to the untreated IOP at all levels above 16 mm Hg and better at higher untreated IOP levels, also in relative terms. Our results further confirm the indication of latanoprost as a first-line therapy for glaucoma.

  • 3.
    Azuara-Blanco, Augusto
    et al.
    Centre for Public Health, Queen's University Belfast, Belfast, United Kingdom.
    McCorry, Noleen
    Centre for Public Health, Queen's University Belfast, Belfast, United Kingdom.
    Tatham, Andrew J.
    Ophthalmology Department, Princess Alexandra Eye Pavilion, Edinburgh, United Kingdom.
    Georgoulas, Stelios
    Ophthalmology, Cambridge University Hospitals NHS Foundation Trust, Cambridge, United Kingdom.
    Founti, Panayiota
    Glaucoma Service, Moorfields Eye Hospital, City Road Campus, London, United Kingdom.
    Schweitzer, Cedric
    Ophthalmology, University Hospital Centre Bordeaux, Bordeaux, France.
    Meier-Gibbons, Frances
    Ophthalmology, Eye Center Rapperswil, Rapperswi, Switzerland.
    Denis, Philippe
    Service d'Ophtalmologie, Hôpital Universitaire de la Croix-Rousse, Hospices Civils de Lyon, Lyon, France.
    Tuulonen, Anja
    Tays Eye Centre, Tampere University Hospital, Tampere, Finland.
    Jóhannesson, Gauti
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    De La Casa, José María Martínez
    Ophthalmology, Hospital Clinico San Carlos, Madrid, Spain.
    Prokosch, Verena
    Department of Ophthalmology, University of Cologne, Koln, Germany.
    Giannoulis, Dimitrios A.
    First Department of Ophthalmology, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece.
    Abegão Pinto, Luis
    Department of Ophthalmology, Santa Maria Hospital, University of Lisbon, Lisboa, Portugal.
    Garway-Heath, David
    Glaucoma Service, Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom.
    Topouzis, Fotis
    First Department of Ophthalmology, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece.
    European Glaucoma Society research priorities for glaucoma care2023Ingår i: British Journal of Ophthalmology, ISSN 0007-1161, E-ISSN 1468-2079Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background/Aims: The goal of health research is to improve patients care and outcomes. Thus, it is essential that research addresses questions that are important to patients and clinicians. The aim of this study was to develop a list of priorities for glaucoma research involving stakeholders from different countries in Europe.

    Methods: We used a three-phase method, including a two-round electronic Delphi survey and a workshop. The clinician and patient electronic surveys were conducted in parallel and independently. For phase I, the survey was distributed to patients from 27 European countries in 6 different languages, and to European Glaucoma Society members, ophthalmologists with expertise in glaucoma care, asking to name up to five research priorities. During phase II, participants were asked to rank the questions identified in phase I using a Likert scale. Phase III was a 1 day workshop with patients and clinicians. The purpose was to make decisions about the 10 most important research priorities using the top 20 priorities identified by patients and clinicians.

    Results: In phase I, 308 patients and 150 clinicians were involved. In phase II, the highest-ranking priority for both patients and clinicians was € treatments to restore vision'. In phase III, eight patients and four clinicians were involved. The top three priorities were € treatments to stop sight loss', € treatments to restore vision' and € improved detection of worsening glaucoma'.

    Conclusion: We have developed a list of priorities for glaucoma research involving clinicians and patients from different European countries that will help guide research efforts and investment.

    Ladda ner fulltext (pdf)
    fulltext
  • 4.
    Barkander, Anna
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Economou, M.A.
    Division of Ophthalmology and Vision, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; Department of Ophthalmology, Capio Sophiahemmet Hospital, Stockholm, Sweden.
    Jóhannesson, Gauti
    Umeå universitet, Medicinska fakulteten, Wallenberg centrum för molekylär medicin vid Umeå universitet (WCMM). Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik. Department of Ophthalmology, University of Iceland, Reykjavik, Iceland.
    Outcomes of iStent inject versus kahook dual blade surgery in glaucoma patients undergoing cataract surgery2023Ingår i: Journal of glaucoma, ISSN 1057-0829, E-ISSN 1536-481X, Vol. 32, nr 10, s. e121-e128Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Précis: iStent Inject implantation (iStent) or Kahook Dual Blade goniotomy (KDB) in combination with phacoemulsification have a similar IOP-lowering effect in all stages of glaucoma, and medications are significantly reduced, especially after KDB.

    PURPOSE: To compare the 2-year efficacy and safety of iStent or KDB in combination with phacoemulsification in eyes with mild to advanced open angle glaucoma.

    METHODS: A retrospective chart review of 153 patients that received iStent or KDB in combination with phacoemulsification at a single center between March 2019 and August 2020. The main outcome parameters at 2 years were: (1) intraocular pressure (IOP)-reduction ≥20%, with a postoperative IOP ≤18 mm Hg, and (2) a reduction of ≥1 medication. Results were stratified by glaucoma grade.

    RESULTS: After 2 years, mean IOP was reduced from 20.3±6.1 to 14.2±4.1 mm Hg in the phaco-iStent group ( P <0.001) and from 20.1±6.1 to 14.7±3.6 mm Hg in the phaco-KDB group ( P <0.001). The mean number of medications was reduced from 3.0±0.9 to 2.6±1.1 in the Phaco-iStent group ( P =0.001) and from 2.3±1.0 to 1.5±1.3 in the Phaco-KDB group ( P <0.001). Success regarding IOP-reduction ≥20% with a postoperative IOP ≤18 mm Hg was met by 46% in the phaco-iStent group and by 51% in the phaco-KDB group. A reduction of ≥1 medication was met by 32% in the phaco-iStent group and by 53% in the phaco-KDB group ( P =0.013). Eyes with mild to moderate and advanced glaucoma responded equally well to the success criteria.

    CONCLUSIONS: iStent and KDB, in combination with phacoemulsification, both lowered IOP effectively in all stages of glaucoma. More medications were reduced after KDB, suggesting that it may be a more effective procedure compared with iStent.

    Ladda ner fulltext (pdf)
    fulltext
  • 5.
    Barkander, Anna
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Economou, Mario A.
    Division of Ophthalmology and Vision, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; Department of Ophthalmology, Capio Sophiahemmet Hospital, Stockholm, Sweden.
    Jóhannesson, Gauti
    Umeå universitet, Medicinska fakulteten, Wallenberg centrum för molekylär medicin vid Umeå universitet (WCMM). Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik. Department of Ophthalmology, University of Iceland, Reykjavik, Iceland.
    Kahook dual-blade goniotomy with and without phacoemulsification in medically uncontrolled glaucoma2023Ingår i: Clinical Ophthalmology, ISSN 1177-5467, E-ISSN 1177-5483, Vol. 17, s. 1385-1394Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Purpose: To evaluate the 2-year efficacy and safety of Kahook dual-blade (KDB) goniotomy in patients with medically uncontrolled glaucoma.

    Methods: This was a retrospective case-series study of 90 consecutive patients with primary open-angle glaucoma (POAG) or pseudoexfoliation glaucoma (PEXG) that underwent KDB goniotomy alone (KDB-alone group) or KDB goniotomy in combination with phacoemulsification (KDB-phaco group) during 2019–2020. All patients were uncontrolled on three or more medications. Surgical success was defined as an IOP reduction ≥20% and/or a reduction of one or more medications at 24 months. We also report IOP levels and number of medications from baseline to 24 months, as well as the need for further glaucoma interventions.

    Results: At 24 months, mean IOP had reduced from 24.8±8.3 to 15.0±5.3 mmHg in the KDB-alone group (P<0.001) and from 22.3 ±5.8 to 13.9±3.0 mmHg in the KDB-phaco group (P<0.001). Medications had reduced from 3.5±0.6 to 3.1±0.9 in the KDB-alone group (P=0.047) and from 3.3±0.5 to 2.3±1.1 in the KDB-phaco group (P<0.001). An IOP reduction ≥20% and/or a reduction with one or more medications was achieved by 47% of eyes in the KDB-alone group and by 76% of eyes in the KDB-phaco group. Eyes with PEXG and POAG responded equally well to the success criteria. During the 24-month follow-up, additional glaucoma surgery or transscleral photocoagulation was performed in 28% of eyes in the KDB-alone group and in 12% of eyes in the KDB-phaco group.

    Conclusion: In patients with medically uncontrolled glaucoma, KDB had a significant IOP-lowering effect after 24 months, but success rates were higher when KDB was performed in combination with cataract surgery compared to stand-alone treatment.

    Ladda ner fulltext (pdf)
    fulltext
  • 6. Bengtsson, Boel
    et al.
    Heijl, Anders
    Jóhannesson, Gauti
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Andersson-Geimer, Sabina
    Aspberg, Johan
    Linden, Christina
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    The Glaucoma Intensive Treatment Study (GITS), a randomized clinical trial: design, methodology and baseline data2018Ingår i: Acta Ophthalmologica, ISSN 1755-375X, E-ISSN 1755-3768, Vol. 96, nr 6, s. 557-566Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Purpose: The primary objective of the ongoing Glaucoma Intensive Treatment Study (GITS) is to evaluate the effectiveness of immediate intensive treatment in comparison with the commonly recommended stepped regimen on the predicted visual field. The two treatment arms are also being compared regarding quality of life (QoL), intraocular pressure (IOP) reduction, frequency of reported side‐effects, adverse events and adherence to prescribed treatment.

    Design: A randomized, two‐centre, prospective open‐labelled treatment trial for open‐angle glaucoma.

    Participants: Individuals aged 40–78 years with previously untreated and newly diagnosed glaucoma with early to moderate visual field loss were eligible.

    Methods: Patients were randomized to initial treatment either using drug monotherapy in accordance with common glaucoma guidelines or using a more intensive approach including eyedrops containing drugs from three different classes combined with 360° laser trabeculoplasty. The patients are to be followed for 5 years at visits including standard automated perimetry, optical coherence tomography (OPT) and tonometry. Change of treatment is allowed and decided upon jointly with the patient as in conventional glaucoma management.Main outcome: The estimated predicted preserved visual field and QoL at end of expected lifetime.

    Results: A total of 242 patients, 45% females, mean age 68 years, were randomized. The median untreated IOP was 24 mm Hg, and the median visual field index (VFI), indicating the percentage of a full field, was 92%.

    Conclusion: Glaucoma Intensive Treatment Study is a clinical trial in which two groups of patients randomized to different initial intensities of IOP‐reducing treatment are being compared with regard to rate of visual field progression and prediction of serious glaucomatous visual field loss at estimated at end of life.

  • 7. Bengtsson, Boel
    et al.
    Linden, Christina
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Heijl, Anders
    Andersson-Geimer, Sabina
    Aspberg, Johan
    Jóhannesson, Gauti
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik. Umeå universitet, Medicinska fakulteten, Wallenberg centrum för molekylär medicin vid Umeå universitet (WCMM).
    The glaucoma intensive treatment study: interim results from an ongoing longitudinal randomized clinical trial2022Ingår i: Acta Ophthalmologica, ISSN 1755-375X, E-ISSN 1755-3768, Vol. 100, nr 2, s. e455-e462Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Purpose: The aim of the study was to determine the perimetric rate of glaucoma progression in the ongoing Glaucoma Intensive Treatment Study (GITS) after 3 years of follow-up.

    Design: This is a randomized, two-centre, prospective open-labelled treatment trial for open-angle glaucoma (OAG). Participants The participants of this study were treatment-naive patients with newly diagnosed OAG, aged 46-78 years, with early to moderate glaucomatous visual field loss scheduled to be followed for 5 years within the study.

    Methods: Patients were randomized to initial treatment with either topical monotherapy or with an intensive approach using drugs from three different classes, plus 360 degrees laser trabeculoplasty. Changes in treatment were allowed. Standard automated perimetry and tonometry were performed and side-effects documented. All results are presented using intention-to-treat analysis.

    Results: A total of 242 patients were randomized. After 3 years of follow-up, eight patients were lost to follow-up, six of whom were deceased. The median untreated baseline intraocular pressure (IOP) was 24 mmHg in both arms. The median IOP was almost constant over the 3 years of follow-up: approximate to 17 mmHg in the mono-arm and approximate to 14 mmHg in the multi-treatment arm. Treatment was intensified in 42% of the mono-treated patients and in 7% of the multi-treated patients. Treatment was reduced in 13% of the multi-treated patients. The median perimetric rate of progression was -0.5%/year in the mono-treated group and -0.1%/year in the multi-treated group (p = 0.03).

    Conclusion: The rate of disease progression was significantly slower in the multi-treated patients than in the mono-treated patients. Further follow-up will show whether this difference is sustained over time.

    Ladda ner fulltext (pdf)
    fulltext
  • 8.
    Eklund, Anders
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Jóhannesson, Gauti
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Johansson, Elias
    Umeå universitet, Medicinska fakulteten, Institutionen för farmakologi och klinisk neurovetenskap, Farmakologi.
    Holmlund, Petter
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper.
    Qvarlander, Sara
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper.
    Ambarki, Khalid
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper.
    Wåhlin, Anders
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Koskinen, Lars-Owe D.
    Umeå universitet, Medicinska fakulteten, Institutionen för farmakologi och klinisk neurovetenskap, Farmakologi.
    Malm, Jan
    Umeå universitet, Medicinska fakulteten, Institutionen för farmakologi och klinisk neurovetenskap, Klinisk neurovetenskap.
    The Pressure Difference between Eye and Brain Changes with Posture2016Ingår i: Annals of Neurology, ISSN 0364-5134, E-ISSN 1531-8249, Vol. 80, nr 2, s. 269-276Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Objective: The discovery of a posture-dependent effect on the difference between intraocular pressure (IOP) and intracranial pressure (ICP) at the level of lamina cribrosa could have important implications for understanding glaucoma and idiopathic intracranial hypertension and could help explain visual impairments in astronauts exposed to microgravity. The aim of this study was to determine the postural influence on the difference between simultaneously measured ICP and IOP.

    Methods: Eleven healthy adult volunteers (age = 46 ± 10 years) were investigated with simultaneous ICP, assessed through lumbar puncture, and IOP measurements when supine, sitting, and in 9° head-down tilt (HDT). The trans–lamina cribrosa pressure difference (TLCPD) was calculated as the difference between the IOP and ICP. To estimate the pressures at the lamina cribrosa, geometrical distances were estimated from magnetic resonance imaging and used to adjust for hydrostatic effects.

    Results: The TLCPD (in millimeters of mercury) between IOP and ICP was 12.3 ± 2.2 for supine, 19.8 ± 4.6 for sitting, and 6.6 ± 2.5 for HDT. The expected 24-hour average TLCPD on earth—assuming 8 hours supine and 16 hours upright—was estimated to be 17.3mmHg. By removing the hydrostatic effects on pressure, a corresponding 24-hour average TLCPD in microgravity environment was simulated to be 6.7mmHg.

    Interpretation: We provide a possible physiological explanation for how microgravity can cause symptoms similar to those seen in patients with elevated ICP. The observed posture dependency of TLCPD also implies that assessment of the difference between IOP and ICP in upright position may offer new understanding of the pathophysiology of idiopathic intracranial hypertension and glaucoma. 

    Ladda ner fulltext (pdf)
    fulltext
  • 9. Gudmundsdottir, Birna S.
    et al.
    Petursdottir, Dyrleif
    Asgrimsdottir, Gudrun M.
    Gottfredsdottir, Maria S.
    Hardarson, Sveinn H.
    Johannesson, Gauti
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Kurkov, Sergey V.
    Jansook, Phatsawee
    Loftsson, Thorsteinn
    Stefansson, Einar
    gamma-Cyclodextrin Nanoparticle Eye Drops with Dorzolamide: Effect on Intraocular Pressure in Man2014Ingår i: Journal of Ocular Pharmacology and Therapeutics, ISSN 1080-7683, E-ISSN 1557-7732, Vol. 30, nr 1, s. 35-41Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Purpose: To test a new drug delivery platform with dorzolamide γ-cyclodextrin (γCD) nanoparticle eye drops for intraocular pressure (IOP) control and safety and compare with Trusopt.® Methods: Self-aggregating γCD nanoparticle eye drops containing 3% dorzolamide were given once a day (QD) and compared with Trusopt given three times a day (TID) in a prospective randomized single masked crossover trial over 24 h. Seventeen subjects with IOP over 18 mmHg were recruited. IOP was measured with an Icare Tonometer Pro.® Results: There was no statistically significant difference in the IOP lowering effect of dorzolamide nanoparticle eye drops QD and Trusopt TID. At peak (4 h), the IOP reduction from baseline was 3.8±2.6 mmHg (18%, P<0.05) in the nanoparticle eye drop group and 3.1±3.7 mmHg in the Trusopt group (14%, P<0.05, P=0.97 between groups). At trough (24 h), the IOP reduction was 1.4±2.8 mmHg (6%, P>0.05) in nanoparticle eye drop group and 1.5±2.0 mmHg (7%, P>0.05) in the Trusopt group (P=0.23 between groups). Burning sensation measured on the visual analogue scale (1–100) was less from the nanoparticle eye drops (12±15) than from the Trusopt (37±30), (P=0.0038). Visual acuity and conjunctival hyperemia did not differ between the two groups. Conclusions: Dorzolamide cyclodextrin nanoparticle eye drops QD lower IOP and the effect seems comparable to Trusopt given TID. The nanoparticle eye drops are well tolerated and seem to have a better safety profile than Trusopt.

  • 10.
    Gustavsson, Simon T.
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Enz, Tim J.
    Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Stockholm, Sweden; Department of Ophthalmology, University of Basel, Basel, Switzerland.
    Tribble, James R.
    Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Stockholm, Sweden.
    Nilsson, Mattias
    Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Stockholm, Sweden.
    Lindqvist, Anna
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Linden, Christina
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Hagström, Anna
    Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Stockholm, Sweden.
    Rutigliani, Carola
    Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Stockholm, Sweden.
    Lardner, Emma
    Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Stockholm, Sweden.
    Stålhammar, Gustav
    Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Stockholm, Sweden.
    Williams, Pete A.
    Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Stockholm, Sweden; Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Eugeniavägen 12, Solna, Sweden.
    Jóhannesson, Gauti
    Umeå universitet, Medicinska fakulteten, Wallenberg centrum för molekylär medicin vid Umeå universitet (WCMM). Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik. Department of Ophthalmology, University of Iceland, Iceland.
    Nicotinamide prevents retinal vascular dropout in a rat model of ocular hypertension and supports ocular blood supply in glaucoma patients2023Ingår i: Investigative Ophthalmology and Visual Science, ISSN 0146-0404, E-ISSN 1552-5783, Vol. 64, artikel-id 34Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    PURPOSE. To investigate whether nicotinamide (NAM) modulates retinal vasculature in glaucoma.

    METHODS. This was a prospective controlled clinical trial investigating animal and human histopathology. Participants included normotensive and ocular hypertensive rats, postmortem human ocular tissue, glaucoma patients (n = 90), and healthy controls (n = 30). The study utilized histopathology, computer-assisted retinal vasculature analysis, optical coherence tomography angiography (OCTA), and NAM treatment. The main outcome measures included retinal vascular parameters in rats as assessed by AngioTool; retinal vasculature integrity in rats and humans as assessed by histopathology, antibody-staining, and ImageJ-based measurements; and retinal perfusion density (PD) and flux index in humans as assessed by OCTA.

    RESULTS. A number of vessel parameters were altered in ocular hypertension/glaucoma compared to healthy controls. NAM treatment improved the retinal vasculature in ocular hypertensive rats, with an increase in mean vessel area, percentage area covered by vessels, total vessel length, total junctions, and junction density as assessed by AngioTool (all P < 0.05); vessel wall integrity as assessed by VE-cadherin antibody staining was also improved (P < 0.01). In humans, as assessed by OCTA, increases in PD in the optic nerve head and macula complete image (0.7%, P = 0.04 and 1.0%, P = 0.002, respectively) in healthy controls, and an increase in the temporal quadrant of the macula (0.7%, P = 0.02) in glaucoma patients was seen after NAM treatment.

    CONCLUSIONS. NAM can prevent retinal vascular damage in an animal model of glaucoma. After NAM treatment, glaucoma patients and healthy controls demonstrated a small increase in retinal vessel parameters as assessed by OCTA.

    Ladda ner fulltext (pdf)
    fulltext
  • 11.
    Holmlund, Petter
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper.
    Stoverud, Karen-Helene
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper.
    Wahlin, Anders
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Wiklund, Urban
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper.
    Malm, Jan
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Neurovetenskaper.
    Jóhannesson, Gauti
    Umeå universitet, Medicinska fakulteten, Wallenberg centrum för molekylär medicin vid Umeå universitet (WCMM). Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Eklund, Anders
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Author Response: Posture-Dependent Collapse of the Optic Nerve Subarachnoid Space: A Combined MRI and Modeling Study2021Ingår i: Investigative Ophthalmology and Visual Science, ISSN 0146-0404, E-ISSN 1552-5783, Vol. 62, nr 15, artikel-id 15Artikel i tidskrift (Övrigt vetenskapligt)
    Ladda ner fulltext (pdf)
    fulltext
  • 12.
    Holmlund, Petter
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Stoverud, Karen-Helene
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Wåhlin, Anders
    Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI). Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Wiklund, Urban
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Malm, Jan
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Neurovetenskaper.
    Jóhannesson, Gauti
    Umeå universitet, Medicinska fakulteten, Wallenberg centrum för molekylär medicin vid Umeå universitet (WCMM). Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Eklund, Anders
    Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI). Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Posture-dependent collapse of the optic nerve subarachnoid space: A combined MRI and modeling study2021Ingår i: Investigative Ophthalmology and Visual Science, ISSN 0146-0404, E-ISSN 1552-5783, Vol. 62, nr 4, artikel-id 26Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    PURPOSE: We hypothesize that a collapse of the optic nerve subarachnoid space (ONSAS) in the upright posture may protect the eyes from large translamina cribrosa pressure differences (TLCPD) believed to play a role in various optic nerve diseases (e.g., glaucoma). In this study, we combined magnetic resonance imaging (MRI) and mathematical modeling to investigate this potential ONSAS collapse and its effects on the TLCPD.

    METHODS: First, we performed MRI on six healthy volunteers in 6° head-down tilt (HDT) and 13° head-up tilt (HUT) to assess changes in ONSAS volume (measured from the eye to the optic canal) with changes in posture. The volume change reflects optic nerve sheath (ONS) distensibility. Second, we used the MRI data and mathematical modeling to simulate ONSAS pressure and the potential ONSAS collapse in a 90° upright posture.

    RESULTS: The MRI showed a 33% decrease in ONSAS volume from the HDT to HUT (P < 0.001). In the upright posture, the simulations predicted an ONSAS collapse 25 mm behind lamina cribrosa, disrupting the pressure communication between the ONSAS and the intracranial subarachnoid space. The collapse reduced the simulated postural increase in TLCPD by roughly 1 mm Hg, although this reduction was highly sensitive to ONS distensibility, varying between 0 and 4.8 mm Hg when varying the distensibility by ± 1 SD.

    CONCLUSIONS: The ONSAS volume along the optic nerve is posture dependent. The simulations supported the hypothesized ONSAS collapse in the upright posture and showed that even small changes in ONS stiffness/distensibility may affect the TLCPD.

    Ladda ner fulltext (pdf)
    fulltext
  • 13.
    Johannesson, Gauti
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Hallberg, Per
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Ambarki, Khalid
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF). Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Eklund, Anders
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF). Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Linden, Christina
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Age-dependency of ocular parameters - a cross sectional study of young and old healthy subjects2015Ingår i: Investigative Ophthalmology and Visual Science, ISSN 0146-0404, E-ISSN 1552-5783, Vol. 56, nr 7, artikel-id Meeting Abstract: 116Artikel i tidskrift (Övrigt vetenskapligt)
    Abstract [en]

    Purpose: To investigate aging effect on ocular parameters inkluding intraocular pressure (IOP) measured with different tonometry methods in healthy young (HY) and elderly (HE) subjects.

    Methods: Fifty eyes of 50 HY subjects (28 females, 22-31 years of age) and 43 eyes of 43 HE subjects (22 females, 64-79 years of age) were included. IOP was measured with four tonometry methods in a standardized order: Ocular Response Analyser (ORA), Dynamic Contour Tonometry (DCT), Applanation Resonance Tonometry (ART) and Goldmann Applanation Tonometry (GAT). Other measurements included axial length (AL), central corneal thickness (CCT), corneal curvature (CC), ocular pulse amplitude (OPA) and aqueous humor (aq).

    Results: The mean IOP (HY/HE; mmHg ± standard deviation) was 13.9 ± 2.7/16.4 ± 3.4 with ORA, 15.1 ± 2.1/16.3 ± 3.1 with DCT, 12.3 ± 2.0/13.7 ± 2.8 with GAT and 13.1 ± 2.2/12.1 ± 2.5 with ART. IOP was significantly higher (difference ± standard error) in HE compared to HY measured with ORA (+2.5 mmHg ± 0.6), GAT (+1.4 ± 0.5) and DCT (+1.2 ± 0.6). There was a trend towards lower IOP in HE when measured with ART (-1.0 ± 0.5, p=0.05). There was no difference between HE and HY in CCT, CC, AL or OPA.

    Conclusions: Tonometry methods are affected differently by age. IOP was measured higher in elderly people with ORA, DCT and GAT in this Scandinavian population. This effect was not seen in measurements with ART. Other ocular parameters did not differ between the age groups indicating that these measured parameters are not influenced by age in this population.

  • 14.
    Johannesson, Gauti
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Hallberg, Per
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Ambarki, Khalid
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF). Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Eklund, Anders
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF). Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Linden, Christina
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Age-dependency of ocular parameters: a cross sectional study of young and elderly healthy subjects2015Ingår i: Graefe's Archives for Clinical and Experimental Ophthalmology, ISSN 0721-832X, E-ISSN 1435-702X, Vol. 253, nr 11, s. 1979-1983Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    To investigate the effect of aging on ocular parameters, including intraocular pressure (IOP), measured with different tonometry methods in healthy young (HY) and healthy elderly (HE) subjects and to study the effect of corneal parameters on tonometry methods. In this prospective, cross-sectional study, fifty eyes of 50 HY subjects (28 females, 22-31 years of age) and 43 eyes of 43 HE subjects (22 females, 64-79) were included. IOP was measured with four tonometry methods in a standardized order: ocular response analyser (ORA), dynamic contour tonometry (DCT), applanation resonance tonometry (ART) and Goldmann applanation tonometry (GAT). Other measurements included axial length (AL), central corneal thickness (CCT), corneal curvature (CC), anterior chamber volume (ACV), corneal hysteresis (CH) and corneal resistance factor (CRF). The mean IOP (HY/HE; mmHg +/- standard deviation (SD)) was 12.2 +/- 2.2/14.1 +/- 3.5 with GAT. IOP was significantly higher (difference +/- standard error) in HE compared to HY measured with an ORA (+3.1 mmHg +/- 0.6), GAT (+1.9 +/- 0.6) and DCT (+1.6 +/- 0.6). No significant difference was found in IOP measured with ART. CH and ACV were significantly lower in HE compared to HY. There was no difference between the groups in CCT, CC, AL or CRF. No tonometry method was dependant on CCT or CC. IOP measured with an ORA and via DCT and GAT was higher in HE compared to HY Swedish subjects, while IOP measured with ART did not differ between the groups. In these homogeneous groups, tonometry methods were independent of CCT and CC.

  • 15.
    Johannesson, Gauti
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Hallberg, Per
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    Eklund, Anders
    Umeå universitet, Medicinska fakulteten, Institutionen för farmakologi och klinisk neurovetenskap, Klinisk neurovetenskap.
    Behndig, Anders
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Linden, Christina
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Effects of topical anaesthetics and repeated tonometry on intraocular pressure2014Ingår i: Acta Ophthalmologica, ISSN 1755-375X, E-ISSN 1755-3768, Vol. 92, nr 2, s. 111-115Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Purpose:

    To investigate the effects of repeated measurements of intraocular pressure (IOP) using Goldmann applanation tonometry (GAT) and applanation resonance tonometry (ART) to identify mechanisms contributing to the expected IOP reduction.

    Methods:

    A prospective, single-centre study with six healthy volunteers. Consecutive repeated series (six measurements/serie/method) were made alternately on both eyes for 1 hr with oxybuprocaine/fluorescein in the right eye and tetracaine in the left. The left eye was Pentacam((R)) photographed before and repeatedly for 20 min after the IOP measurements. On a separate occasion, the same volunteers received the same amount of anaesthetic drops for 1 hr but without repeated IOP measurements.

    Results:

    A significant IOP reduction occurred with both ART and GAT in the oxybuprocaine-treated eye, -4.4 mmHg and -3.8 mmHg, respectively and with ART in the tetracaine eye, -2.1 mmHg. There was a significant difference in IOP reduction between the oxybuprocaine and tetracaine eyes with ART. There was a significant drop in anterior chamber volume (ACV) immediately after the IOP measurements, -12.6 mu l that returned to pretrial level after 2 min. After 1 hr of receiving anaesthetic eye drops (without IOP measurements), the IOP decreased significantly in the oxybuprocaine eye for both ART and GAT, -3.1 and -1.7 mmHg, respectively, but not in the tetracaine eye (p = 0.72).

    Conclusion:

    The IOP reduction cannot be explained solely by aqueous humor being pressed out of the anterior chamber. While significant IOP reduction occurred with both tetracaine and oxybuprocaine after repeated mechanical applanation, the IOP reduction was significantly greater with oxybuprocaine.

  • 16.
    Johannesson, Gauti
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Hallberg, Per
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Eklund, Anders
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Koskela, Timo
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Linden, Christina
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Change in intraocular pressure measurement 2 years after myopic laser-assisted subepithelial keratectomy2012Ingår i: Journal of cataract and refractive surgery, ISSN 0886-3350, E-ISSN 1873-4502, Vol. 38, nr 9, s. 1637-1642Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    PURPOSE: To evaluate intraocular pressure (IOP) measurements 24 months after laser-assisted subepithelial keratectomy (LASEK) with 3 tonometry methods-Goldmann applanation tonometry (DCT), Pascal dynamic contour tonometry (DCT), and applanation resonance tonometry (ART)-and to compare them with measurements taken preoperatively and 3 and 6 months postoperatively. SETTING: Department of Ophthalmology, Umea University, lima Sweden. DESIGN: Prospective randomized single-center. METHODS: One randomized eye per person from myopic healthy individuals who had LASEK was included. Visual acuity, central corneal thickness (CCT), corneal curvature, and IOP were measured at all time points. Six IOP measurements were performed per method, with a 5-minute lapse between methods. RESULTS: The study evaluated 38 eyes. Two years after LASEK, dynamic ART was the only method that did not measure significantly lower IOP than before LASEK (mean -0.2 mm Hg +/- 1.6 [SD]). The greatest difference was with GAT (mean -1.9 +/- 1.7 mm Hg) followed by static ART (mean -1.2 +/- 1.6 mm Hg) and then DCT (mean -0.9 +/- 1.3 mm Hg). All methods measured significantly lower IOP at 3 months and 6 months. CONCLUSIONS: Dynamic ART, which analyses IOP measurement during indentation, showed no significant difference in measured IOP after 24 months. The convex tip of the ART device and the continuous sampling of data during corneal indentation seem to be factors in why dynamic ART was less affected by corneal properties and therefore more suitable for IOP measurement in LASEK-treated eyes, although this must be confirmed in larger trials.

  • 17.
    Johannesson, Gauti
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Shulman, Shiri
    Ruckert, Rene
    Stefansson, Einar
    In Vivo Visualization of Large Choroidal Vessels Obliteration in Geographic Atrophy2017Ingår i: Retina, ISSN 0275-004X, E-ISSN 1539-2864, Vol. 37, nr 2, s. E24-E24Artikel i tidskrift (Refereegranskat)
  • 18.
    Jóhannesson, Gauti
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Intraocular pressure: clinical aspects and new measurement methods2011Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Intraocular pressure (IOP) measurement is a routine procedure and a fundament in glaucoma care. Elevated IOP is the main risk factor for glaucoma, and to date, reduction of IOP is the only possible treatment.

    In a retrospective clinical material, the prevalence of open angle glaucoma was estimated on the west coast of Iceland. IOP measurement and optic nerve head examination were used to capture glaucoma suspects, within the compulsory ophthalmological examination for the prescription of eye glasses. The results were mainly in agreement with a recent prospective study in the same region. This indicated that retrospective data, under certain conditions, may contribute with useful information on the prevalence of glaucoma. However, normal tension glaucoma is underestimated if perimetry and/or fundus photography are not included in the examination.

    Three studies focused on the measurement of IOP. Goldmann applanation tonometry (GAT) is the standard method. GAT is affected by corneal properties, e.g. central corneal thickness (CCT) and corneal curvature (CC). Refractive surgery changes these properties. This has put focus on how corneal biomechanics translate into tonometric errors and stimulated the development of new methods. As a result, Pascal

    ® Dynamic Contour Tonometry (PDCT) and Icare® rebound tonometry have been introduced. A method under development by our research group is Applanation Resonance Tonometry (ART). It is based on resonance technology and estimates IOP from continuous measurement of force and contact area.

    Comparison of PDCT, Icare and GAT in a prospective study showed that the concordance to GAT was close to the limits set by the International Standard Organization (ISO) for PDCT, while Icare was outside the limits.

    To investigate if laser-assisted subepithelial keratectomy (LASEK) affects tonometry, a study was performed where measurements with GAT, PDCT and ART were obtained before, three and six months after LASEK. The hypothesis was that PDCT and ART would be less affected by LASEK than GAT. The results showed a statistically significant reduction of measured IOP three and six months after LASEK for all tonometry methods. Change in visual acuity and IOP between three and six months suggested a prolonged postoperative process.

    A servo-controlled prototype (ART

    servo) was developed. A study was undertaken to assess the agreement of ARTservo and a further developed v

    manual prototype (ART

    manual) with GAT. The study design was in accordance with the requirements of the ISO standard for tonometers. ARTmanual fulfilled the precision requirements of the ISO standard. ARTservo did not meet all the requirements of the standard at the highest pressure levels.

    Four tonometry methods, GAT, PDCT, Icare and ART, were investigated. None of them was independent of both CCT and CC. The inconsistencies in the results emphasize the importance of study design. A meta-analysis comprising healthy eyes (IOP ≤ 21 mmHg) in the three papers, revealed age as an important confounder.

    In summary, glaucoma prevalence in Iceland was investigated and the results indicated that a retrospective approach can contribute with meaningful information. ART and PDCT had a similar agreement to GAT. ART

    manual fulfilled the precision requirements set by the ISO-standard, ARTservo and PDCT were close, while Icare was distinctly outside the limits. All tonometry methods were affected by LASEK and no method was completely independent of corneal properties.

    Ladda ner fulltext (pdf)
    FULLTEXT01
  • 19.
    Jóhannesson, Gauti
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Abouzeid, Hana
    Somner, John Edward Almond
    Association between rate of binocular visual field change and vision-related quality of life: novel finding or spurious association?2014Ingår i: JAMA ophthalmology, ISSN 2168-6165, E-ISSN 2168-6173, Vol. 132, nr 6, s. 784-785Artikel i tidskrift (Refereegranskat)
  • 20.
    Jóhannesson, Gauti
    et al.
    Umeå universitet, Medicinska fakulteten, Wallenberg centrum för molekylär medicin vid Umeå universitet (WCMM). Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Eklund, Anders
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Linden, Christina
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Intracranial and Intraocular Pressure at the Lamina Cribrosa: Gradient Effects2018Ingår i: Current Neurology and Neuroscience Reports, ISSN 1528-4042, E-ISSN 1534-6293, Vol. 18, nr 5, artikel-id 25Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    Purpose of Review: A pressure difference between the intraocular and intracranial compartments at the site of the lamina cribrosa has been hypothesized to have a pathophysiological role in several optic nerve head diseases. This paper reviews the current literature on the translamina cribrosa pressure difference (TLCPD), the associated pressure gradient, and its potential pathophysiological role, as well as the methodology to assess TLCPD.

    Recent Findings: For normal-tension glaucoma (NTG), initial studies indicated low intracranial pressure (ICP) while recent findings indicate that a reduced ICP is not mandatory.

    Summary: Data from studies on the elevated TLCPD as a pathophysiological factor of NTG are equivocal. From the identification of potential postural effects on the cerebrospinal fluid (CSF) communication between the intracranial and retrolaminar space, we hypothesize that the missing link could be a dysfunction of an occlusion mechanism of the optic nerve sheath around the optic nerve. In upright posture, this could cause an elevated TLCPD even with normal ICP and we suggest that this should be investigated as a pathophysiological component in NTG patients.

    Ladda ner fulltext (pdf)
    fulltext
  • 21.
    Jóhannesson, Gauti
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik. Umeå universitet, Medicinska fakulteten, Wallenberg centrum för molekylär medicin vid Umeå universitet (WCMM). Department of Ophthalmology, Faculty of Medicine, National University Hospital, University of Iceland, Reykjavik, Iceland.
    Gottfredsdottir, Maria Soffia
    Asgrimsdottir, Gudrun Marta
    Loftsson, Thorsteinn
    Stefansson, Einar
    Can postoperative dexamethasone nanoparticle eye drops replace mitomycin C in trabeculectomy?2020Ingår i: Acta Ophthalmologica, ISSN 1755-375X, E-ISSN 1755-3768, Vol. 98, nr 6, s. 607-612Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Purpose: Compare (a) nonmitomycin C (MMC) trabeculectomy and 1.5% dexamethasone nanoparticle (DexNP) eye drops postoperatively with (b) trabeculectomy with MMC and Maxidex® eye drops postoperatively.

    Methods: Randomized prospective single masked clinical trial with 20 patients with primary open‐angle glaucoma undergoing primary trabeculectomy. The study group consisted of 10 patients without MMC intraoperatively and postoperative DexNP eye drops, and the control group consisted of 10 patients treated with MMC intraoperatively and postoperative Maxidex®. The drops were tapered out over 8 weeks. The main outcome measures were as follows: rates of complete success, that is intraocular pressure (IOP) within target pressures at different time‐points without IOP‐lowering medication, or reoperation. Secondary outcome measures included the following: relative success rate (with IOP‐lowering medications), number of glaucoma medications and reoperations. Patients were followed for 36 months.

    Results: Both groups showed similar postoperative course and IOP reduction. Intraocular pressures (IOPs) in the DexNP group and in the control group were 25.6 and 24.4 mmHg, respectively, at baseline. Intraocular pressures (IOPs) were reduced to 13.2 and 14.5 mmHg at 12 months, 11.7 and 12.6 mmHg at 24 months and 11.7 and 12.1 mmHg at 36 months, respectively. There were no statistically significant differences between the groups in absolute (p = 0.36) or relative (p = 1.0) success rates, number of medications (p = 0.71) or reoperations (p = 1.0) between the groups at any time‐point.

    Conclusions: DexNP eye drops are effective postoperative treatment following trabeculectomy. The potent anti‐inflammatory and antifibrotic effect of DexNP may offer an alternative to mitomycin C in glaucoma surgery.

    Ladda ner fulltext (pdf)
    fulltext
  • 22.
    Jóhannesson, Gauti
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Gudmundsdóttir, Gudrún J
    Rejykjavik, Island.
    Lindén, Christina
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Can the prevalence of open-angle glaucoma be estimated from a retrospective clinical material? A study on the west coast of Iceland.2005Ingår i: Acta Ophthalmologica Scandinavica, ISSN 1395-3907, E-ISSN 1600-0420, Vol. 83, nr 5, s. 549-553Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    PURPOSE: To explore the possibility of estimating the prevalence of open-angle glaucoma (OAG) on the west coast of Iceland using a clinical retrospective material, and to compare that estimate with the results from a recent prospective Icelandic study.

    METHODS: The compulsory ophthalmological examination for the prescription of eye glasses in combination with information obtained from Statistics Iceland were used to establish the prevalence of glaucoma in Akranes and to estimate the minimum prevalence for the greater west coast area. A recent prospective study from Iceland was used as reference.

    RESULTS: In all, 79% of 1443 Akranes inhabitants aged 50 years or more had visited the eye clinic at least once between 1996 and 2001. The prevalence of OAG was 4.8% (95% CI 3.6-6.1). The minimum prevalence for the west coast was 3.8% (95% CI 3.2-4.4). The prevalence increased with age (p < 0.001). The overall prevalence was similar to that of recently published prospective data but the prevalence of normal tension glaucoma (NTG) was lower.

    CONCLUSION: The results from the two studies are similar in many respects, which indicates that retrospective data may supply meaningful information on glaucoma prevalence. Important sources of error are the selection and attendance of patients, screening methods and diagnostic criteria. If routine examination does not include fundus photography and/or perimetry, the prevalence of NTG will be underestimated.

  • 23.
    Jóhannesson, Gauti
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Hallberg, Per
    Eklund, Anders
    Koskela, Timo
    Lindén, Christina
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Change in intraocular pressure measurement after myopic LASEK: a study evaluating Goldmann, Pascal and applanation resonance tonometry2012Ingår i: Journal of glaucoma, ISSN 1057-0829, E-ISSN 1536-481X, Vol. 21, nr 4, s. 255-259Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Purpose: To prospectively evaluate 3 tonometry methods—the gold standard, Goldmann applanation tonometry, a new method, Pascal dynamic contour tonometry (PDCT), and a method under development, applanation resonance tonometry (ART)—with respect to intraocular pressure (IOP) measurements before, 3 and 6 months after laser-assisted subepithelial keratectomy (LASEK).

    Materials and Methods: One randomly assigned eye of each of 53 healthy individuals, who underwent LASEK surgery for myopia was studied. Visual acuity, central corneal thickness, corneal curvature, and IOP were measured at each visit. Six IOP measurements/methods with 5 minutes pause between methods were performed.

    Results: All tonometry methods measured a significantly lower IOP after LASEK correction by a mean of −3.1 diopters. The IOP reduction was largest after 6 months for Goldmann applanation tonometry (−1.7±1.8 mm Hg) followed by ARTstat (−1.2±1.5 mm Hg), PDCT (−1.1±1.6 mm Hg), and ARTdyn (−1.0±1.5 mm Hg). The reduction of IOP did not differ significantly between different methods (P=0.11). There was a significant further reduction of measured IOP for PDCT between 3 and 6 months (−0.5±1.0 mm Hg). Uncorrected visual acuity improved significantly between 3 and 6 months postoperatively from 1.32±0.28 to 1.43±0.27.

    Conclusions: All tonometry methods measured a significant, but low, reduction of IOP 3 and 6 months after LASEK. Further change in visual acuity and IOP measurements between 3 and 6 months suggest a still ongoing postoperative process.

  • 24.
    Jóhannesson, Gauti
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Hallberg, Per
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Eklund, Anders
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Lindén, Christina
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Introduction and clinical evaluation of servo-controlled applanation resonance tonometry2012Ingår i: Acta Ophthalmologica Scandinavica, ISSN 1395-3907, E-ISSN 1600-0420, Vol. 90, nr 7, s. 677-682Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Purpose:  In recent years, Applanation Resonance Tonometry (ART) has been suggested for intraocular pressure (IOP) measurements. The manual version of ART (ARTmanual) has been further developed, and to improve usability, an automatic servo-controlled prototype (ARTservo) has been proposed. The aim of this study was to assess the limits of agreement (LoA) of ARTmanual and ARTservo as compared with the reference method, Goldmann Applanation Tonometry (GAT).

    Methods:  This was a prospective single-centre study on 152 eyes from 77 subjects. It was designed according to International Standard Organization’s (ISO) requirements for tonometers (ISO 2001). Intraocular pressure was measured six times/method in a standardized order. The ART technique has two available analysis procedures: a dynamic one that measures IOP during the indentation phase and a static one that causes a Goldmann-like measurement during two seconds of full applanation. The 95% LoA was defined as ±1.96 × standard deviation of difference against GAT.

    Results:  Mean IOP for GAT was 19.1 mmHg (range: 10–37 mmHg). The 95% LoA of ARTmanual was ±4.5 mmHg for both dynamic and static analyses. The 95% LoA of ARTservo was ±5.7 mmHg for dynamic and ±4.9 mmHg for static analyses.

    Conclusions:  This study confirms that the ART methodology is feasible. The further developed ARTmanual fulfilled the ISO standard with both the dynamic and the static analysis techniques. ARTservo with static analysis was close to fulfilling the standard but failed to do so in the highest IOP range. ARTservo has the potential to greatly improve usability if further development is completed.

  • 25.
    Jóhannesson, Gauti
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Hallberg, Per
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Eklund, Anders
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Lindén, Christina
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Pascal, ICare and Goldmann applanation tonometry: a comparative study2008Ingår i: Acta ophthalmologica, ISSN 1755-3768, Vol. 86, nr 6, s. 614-621Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    PURPOSE: To compare intraocular pressure (IOP) measurements by Pascal, ICare and Goldmann applanation tonometry (GAT), to evaluate the effects of central corneal thickness (CCT) and curvature on IOP measurement and to estimate the intra-observer variability.

    METHODS: A prospective, single-centre study of 150 eyes with a wide range of pressures. Six masked IOP measurements/method; corneal thickness and curvature were studied for each eye. GAT was the reference.

    RESULTS: IOPPascal and IOPICare correlated with IOPGAT (r = 0.91, 0.89). Mean ICare measurement exceeded GAT by 2 mmHg. Pascal measured higher than GAT at low IOPs and lower at high IOPs. For every 10 mmHg increase in IOP above 31 mmHg, Pascal measured 2 mmHg lower than GAT and vice versa. CCT was correlated significantly with IOPGAT (r = 0.23) and IOPICare (r = 0.43) but not with IOPPascal (P = 0.12). CCT was correlated with age. In a subgroup (>50 years), ICare and the difference between IOPGAT and IOPPascal were affected significantly by the CCT, whereas IOPGAT and IOPPascal were not. Corneal curvature was correlated significantly with IOPGAT (r = -0.27) and IOPPascal (r = -0.26) but not with IOPICare (P = 0.60). Intra-observer variability within each set of six measurements was approximately 2 mmHg, irrespective of method.

    CONCLUSION: This study showed a reasonable overall correlation and concordance between the IOP obtained with the three instruments. None of the methods were completely independent of the biomechanical properties of the cornea. ICare showed a significant dependency upon CCT, whereas GAT and Pascal showed a significant dependency on corneal curvature. All methods showed intra-observer variability, which leaves room for further improvement of methods.

  • 26.
    Jóhannesson, Gauti
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Lindén, Christina
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Eklund, Anders
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Behndig, Anders
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Hallberg, Per
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Can we trust intraocular pressure measurements in eyes with intracameral air?2014Ingår i: Graefe's Archives for Clinical and Experimental Ophthalmology, ISSN 0721-832X, E-ISSN 1435-702X, Vol. 252, nr 10, s. 1607-1610Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    PURPOSE: To evaluate the effect of intracameral air on intraocular pressure (IOP) measurements using Goldmann applanation tonometry (GAT) and applanation resonance tonometry (ART) in an in-vitro porcine eye model.

    METHODS: IOP was measured on thirteen freshly enucleated eyes at three reference pressures: 20, 30, and 40 mmHg. Six measurements/method were performed in a standardized order with GAT and ART respectively. Air was injected intracamerally in the same manner as during Descemet's stripping endothelial keratoplasty (DSEK) and Descemet's membrane endothelial keratoplasty (DMEK), and the measurements were repeated.

    RESULTS: Measured IOP increased significantly for both tonometry methods after air injection: 0.7 ± 2.1 mmHg for GAT and 10.6 ± 4.9 mmHg for ART. This difference was significant at each reference pressure for ART but not for GAT.

    CONCLUSIONS: Although slightly affected, this study suggests that we can trust GAT IOP-measurements in eyes with intracameral air, such as after DSEK/DMEK operations. Ultrasound-based methods such as ART should not be used.

  • 27.
    Jóhannesson, Gauti
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik. Department of Ophthalmology, National University Hospital, University of Iceland, Reykjavik, Iceland.
    Moya-Ortega, Maria D
    Ásgrímsdóttir, Gudrun Marta
    Agnarsson, Bjarni A
    Lund, Sigrún H
    Loftsson, Thorsteinn
    Stefánsson, Einar
    Dorzolamide cyclodextrin nanoparticle suspension eye drops and trusopt in rabbit2014Ingår i: Journal of Ocular Pharmacology and Therapeutics, ISSN 1080-7683, E-ISSN 1557-7732, Vol. 30, nr 6, s. 464-467Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Abstract Purpose: Dorzolamide nanoparticle γ-cyclodextrin eye drops may prolong the effect of dorzolamide on intraocular pressure. We test whether the nanoparticle drops have an irritating or toxic effect on the eye in an in vivo rabbit model. Methods: Eighteen pigmented rabbits were divided into 4 groups receiving dorzolamide nanoparticle γ-cyclodextrin eye drops×1/day or×2/day, Trusopt(®) (dorzolamide HCl)×3/day, and untreated controls that received no drops. The rabbits received treatment for 1 month. After sacrifice, 33 eyes and 25 Harderian glands were evaluated for histopathology in a masked way. Results: Mild inflammation was seen in 19/31 eyes and 13/23 Harderian glands. The difference in inflammation (n=eyes/n=glands)between the γ-cyclodextrin nanoparticle eye drops×1/day (n=5/5),×2/day (n=5/3), Trusopt (n=7/4), or untreated control (n=2/0) groups was nonsignificant in both eyes and glands (P=0.87 and P=0.92) Acute inflammation was seen in 1 Harderian gland that received γ-cyclodextrin nanoparticle eye drops×2/day. The difference in conjunctival injection between the groups was nonsignificant (P=0.30). Conclusions: Dorzolamide γ-cyclodextrin nanoparticle eye drops are no more locally toxic or irritating to the eye than Trusopt.

  • 28.
    Jóhannesson, Gauti
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik. Department of Ophthalmology, University of Iceland, National University Hospital, IS 101 Reykjavík, Iceland.
    Moya-Ortega, Maria D
    Faculty of Pharmaceutical Sciences, University of Iceland, Reykjavik, Iceland and Oculis Ehf., Reykjavik, Iceland.
    Ásgrímsdóttir, Gudrún Marta
    Oculis Ehf., Reykjavik, Iceland .
    Lund, Sigrún H
    Faculty of Medicine, University of Iceland, Reykjavik, Iceland.
    Thorsteinsdóttir, Margrét
    Loftsson, Thorsteinn
    Faculty of Pharmaceutical Sciences, University of Iceland, Reykjavik, Iceland.
    Stefánsson, Einar
    Department of Ophthalmology, University of Iceland, National University Hospital, IS 101 Reykjavík, Iceland .
    Kinetics of γ-cyclodextrin nanoparticle suspension eye drops in tear fluid2014Ingår i: Acta Ophthalmologica, ISSN 1755-375X, E-ISSN 1755-3768, Vol. 92, nr 6, s. 550-556Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    PURPOSE: We have developed nanoparticle γ-cyclodextrin dexamethasone (DexNP) and dorzolamide (DorzNP) eye drops that provide sustained high drug concentrations on the eye surface. To test these characteristics, we measured dexamethasone and dorzolamide levels in tear fluid in humans following eye drop administration.

    METHODS: Concentration of dexamethasone was measured by mass spectrometry. One drop of DexNP was instilled into one eye. Tear fluid was sampled with microcapillary pipettes at seven time-points after drop instillation. Control eyes received Maxidex(®) (dexamethasone). The same procedure was performed for dorzolamide with DorzNP and Trusopt(®) .

    RESULTS: Six subjects were included in each group. The peak concentration (μg/ml ± standard deviation) of dexamethasone for DexNP eye drops (636.6 ± 399.1) was up to 19-fold higher than with Maxidex(®) (39.3 ± 18.9) (p < 0.001). At 4 hr, DexNP was still 10 times higher than Maxidex(®) . In addition, DexNP resulted in about 30-fold higher concentration of dissolved dexamethasone in the tear fluid of extended time period allowing more drug to partition into the eye tissue. The overall concentration of dorzolamide was about 50% higher for DorzNP (59.5 ± 76.9) than Trusopt(®) (40.0 ± 76.7) (p < 0.05).

    CONCLUSION: The results indicate high and extended concentration of dissolved dexamethasone with DexNP, which can explain the greater and longer lasting effect of dexamethasone in the cyclodextrin nanoparticle drug delivery platform. Dexamethasone seems to fit the cyclodextrin nanoparticle suspension drug delivery platform with longer duration and higher concentrations in tear fluid than available commercial drops, while dorzolamide is less suitable.

  • 29.
    Jóhannesson, Gauti
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik. Umeå universitet, Medicinska fakulteten, Wallenberg centrum för molekylär medicin vid Umeå universitet (WCMM).
    Qvarlander, Sara
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Wåhlin, Anders
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI). Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Ambarki, Khalid
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Hallberg, Per
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Eklund, Anders
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Lindén, Christina
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Intraocular Pressure Decrease Does Not Affect Blood Flow Rate of Ophthalmic Artery in Ocular Hypertension2020Ingår i: Investigative Ophthalmology and Visual Science, ISSN 0146-0404, E-ISSN 1552-5783, Vol. 61, nr 12, artikel-id 17Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    PURPOSE: To investigate if decrease of IOP affects the volumetric blood flow rate in the ophthalmic artery (OA) in patients with previously untreated ocular hypertension.

    METHODS: Subjects with untreated ocular hypertension (n = 30; mean age 67 +/- 8 years; 14 females) underwent ophthalmologic examination and a 3-Tesla magnetic resonance imaging investigation. The magnetic resonance imaging included three-dimensional high-resolution phase-contrast magnetic resonance imaging to measure the OA blood flow rate. The subjects received latanoprost once daily in the eye with higher pressure, the untreated eye served as control. The same measurements were repeated approximately 1 week later.

    RESULTS: The mean OA blood flow rate before and after treatment was 12.4 +/- 4.4 and 12.4 +/- 4.6 mL/min in the treated eye (mean +/- SD; P = 0.92) and 13.5 +/- 5.2 and 13.4 +/- 4.1 mL/min in the control eye (P = 0.92). There was no significant difference between the treated and control eye regarding blood flow rate before (P = 0.13) or after treatment (P = 0.18), or change in blood flow rate after treatment (0.1 +/- 3.1 vs.-0.1 +/- 4.0 mL/min, P = 0.84). Latanoprost decreased the IOP by 7.2 +/- 3.1 mm Hg in the treated eye (P < 0.01).

    CONCLUSIONS: The results indicate that a significant lowering of IOP does not affect the blood flow rate of the OA in ocular hypertension subjects. The ability to maintain blood supply to the eye independent of the IOP could be a protective mechanism in preserving vision in subjects with ocular hypertension.

    Ladda ner fulltext (pdf)
    fulltext
  • 30.
    Jóhannesson, Gauti
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik. Department of ophthalmology, Faculty of medicine, University of Iceland, Reykjavik, Iceland.
    Stefánsson, Einar
    Loftsson, Thorsteinn
    Microspheres and Nanotechnology for Drug Delivery2016Ingår i: Developments in ophthalmology, ISSN 1662-2790, Vol. 55, s. 93-103Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Ocular drug delivery to the posterior segment of the eye can be accomplished by invasive drug injections into different tissues of the eye and noninvasive topical treatment. Invasive treatment involves the risks of surgical trauma and infection, and conventional topical treatments are ineffective in delivering drugs to the posterior segment of the eye. In recent years, nanotechnology has become an ever-increasing part of ocular drug delivery. In the following, we briefly review microspheres and nanotechnology for drug delivery to the eye, including different forms of nanotechnology such as nanoparticles, microparticles, liposomes, microemulsions and micromachines. The permeation barriers and anatomical considerations linked to ocular drug delivery are discussed and a theoretical overview on drug delivery through biological membranes is given. Finally, in vitro, in vivo and human studies of x03B3;-cyclodextrin nanoparticle eyedrop suspensions are discussed as an example of nanotechnology used for drug delivery to the eye.

  • 31.
    Jóhannesson, Gauti
    et al.
    Umeå universitet, Medicinska fakulteten, Wallenberg centrum för molekylär medicin vid Umeå universitet (WCMM). Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik. Department of Ophthalmology, University of Iceland, Reykjavik, Iceland.
    Stille, Ulf
    Department of Ophthalmology, Falu Lasarett, Falun, Sweden.
    Taube, Amelie Botling
    Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
    Karlsson, Markus
    Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden.
    Kalaboukhova, Lada
    Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
    Bergström, Anders
    Department of Clinical Sciences, Ophthalmology, Lund University, Lund, Sweden.
    Peters, Dorothea
    Department of Clinical Sciences, Ophthalmology, Lund University, Malmö, Sweden.
    Lindén, Christina
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Guidelines for the management of open-angle glaucoma: national program area eye diseases, national working group glaucoma2024Ingår i: Acta Ophthalmologica, ISSN 1755-375X, E-ISSN 1755-3768, Vol. 102, nr 2, s. 135-150Artikel i tidskrift (Refereegranskat)
    Ladda ner fulltext (pdf)
    fulltext
  • 32.
    Kristiansen, Martin
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Holmlund, Petter
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Linden, Christina
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Eklund, Anders
    Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI). Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Jóhannesson, Gauti
    Umeå universitet, Medicinska fakulteten, Wallenberg centrum för molekylär medicin vid Umeå universitet (WCMM). Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik. Department of Ophthalmology, University of Iceland, Reykjavik, Iceland.
    Optic nerve subarachnoid space posture dependency: an MRI study in subjects with normal tension glaucoma and healthy controls2023Ingår i: Investigative Ophthalmology and Visual Science, ISSN 0146-0404, E-ISSN 1552-5783, Vol. 64, nr 15, artikel-id 20Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Purpose: The purpose of this study was to examine the differences of optic nerve subarachnoid space (ONSAS) volume in patients with normal tension glaucoma (NTG) and healthy controls in different body positions.

    Methods: Eight patients with NTG and seven healthy controls underwent magnetic resonance imaging (MRI) examinations in head up tilt (HUT) +11 degrees and head down tilt (HDT) -5 degrees positions according to a randomized protocol determining the starting position. The ONSAS volume in both body positions was measured and compared between the two groups. The results were analyzed using a generalized linear model.

    Results: Between HDT and HUT, the postural ONSAS volume change was dependent on starting position (P < 0.001) and group (P = 0.003, NTG versus healthy). A subgroup analysis of those that were randomized to HUT examination first, coming directly from an upright position, showed that the patients with NTG had significantly larger positional ONSAS volume changes compared to the healthy controls; 121 ± 22 µL vs. 65 ± 37 µL (P = 0.049). Analysis of the ONSAS volume distribution showed different profiles for patients with NTG and healthy controls.

    Conclusions: There was a significant difference in ONSAS volume change between patients with NTG and healthy subjects when subjected to posture changes, specifically when going from upright to head-down posture. This indicates that patients with NTG had been exposed to a lower ONSAS pressure when they came from the upright posture, which suggests an increased translaminar pressure difference in upright position. This may support the theory that NTG has a dysfunction in an occlusion mechanism of the optic nerve sheath that could cause abnormally negative ONSAS pressures in upright posture.

    Ladda ner fulltext (pdf)
    fulltext
  • 33.
    Kristiansen, Martin
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Linden, Christina
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Qvarlander, Sara
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Wåhlin, Anders
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Ambarki, Khalid
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Hallberg, Per
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Eklund, Anders
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Jóhannesson, Gauti
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Blood flow rate of ophthalmic artery in patients with normal tension glaucoma and healthy controls2018Ingår i: Investigative Ophthalmology and Visual Science, ISSN 0146-0404, E-ISSN 1552-5783, Vol. 59, nr 9Artikel i tidskrift (Övrigt vetenskapligt)
    Abstract [en]

    Purpose: To determine the blood flow rate of the ophthalmic artery (OA) in patients with Normal Tension Glaucoma (NTG) compared to age-matched healthy controls using phase-contrast magnetic resonance imaging (PCMRI).

    Methods: Seventeen patients with treated NTG (11 female; mean age: 70±9 years) and 16 age-matched healthy controls (10 female; mean age: 71±9 years) underwent PCMRI using a 3-Tesla scanner as well as ophthalmological examinations including visual acuity, Goldmann Applanation Tonometry, Humphrey perimetry and fundoscopy. Ophthalmic blood flow was acquired using a 2D PCMRI sequence set to a spatial resolution of 0.35mm/pixel. Mean flow rate and cross-sectional area was calculated using Segment Software. The eye with the most severe glaucomatous damage classified by visual field index (VFI) was chosen for comparison. The primary outcome was blood flow rate of OA.

    Results: The mean VFI was 41% ± 26 (mean±SD) for the worse NTG eyes. The intraocular pressure was 13.6±2.6 mmHg for NTG eyes and 13.8±2.1 mmHg for control eyes. The blood flow rate in the NTG group was 9.6±3.7 ml/min compared to 11.8±5.5 ml/min in the control group. The area was 1.7±0.3 mm2 and 2.0±0.6 mm2 respectively. No statistical significance was found between NTG and the control group regarding blood flow rate (p=0.07) or OA area (p=0.12).

    Conclusions: Despite OA being an anastomosis between the intracranial and extracranial circulation, possibly generating an eye unrelated variability in blood flow, we found a trend level reduction of approximately 2 ml/min in NTG. The finding warrants blood flow rate analysis of smaller arteries specifically supplying the eye, e.g. the central retinal artery.

  • 34.
    Kristiansen, Martin
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Lindén, Christina
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Qvarlander, Sara
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Wåhlin, Anders
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI). Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Ambarki, Khalid
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Hallberg, Per
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Eklund, Anders
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Jóhannesson, Gauti
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik. Umeå universitet, Medicinska fakulteten, Wallenberg centrum för molekylär medicin vid Umeå universitet (WCMM).
    Feasibility of MRI to assess differences in ophthalmic artery blood flow rate in normal tension glaucoma and healthy controls2021Ingår i: Acta Ophthalmologica, ISSN 1755-375X, E-ISSN 1755-3768, Vol. 99, nr 5, s. e679-e685Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Purpose: To examine feasibility of phase-contrast magnetic resonance imaging (PCMRI) and to assess blood flow rate in the ophthalmic artery (OA) in patients with normal tension glaucoma (NTG) compared with healthy controls.

    Methods: Sixteen patients with treated NTG and 16 age- and sex-matched healthy controls underwent PCMRI using a 3-Tesla scanner and ophthalmological examinations. OA blood flow rate was measured using a 2D PCMRI sequence with a spatial resolution of 0.35 mm(2).

    Results: The blood flow rate in the NTG group was 9.6 +/- 3.9 ml/min [mean +/- SD] compared with 11.9 +/- 4.8 ml/min in the control group. Resistance Index (RI) and Pulsatility Index (PI) were 0.73 +/- 0.08 and 1.36 +/- 0.29, respectively, in the NTG group and 0.68 +/- 0.13 and 1.22 +/- 0.40, respectively, in the healthy group. The mean visual field index (VFI) was 46% +/- 25 for the worse NTG eyes. The measured differences observed between the NTG group and the control group in blood flow rate (p = 0.12), RI (p = 0.18) and PI (p = 0.27) were non-significant.

    Conclusions: This case-control study, using PCMRI, showed a slight, but non-significant, reduction in OA blood flow rate in the NTG patients compared with the healthy controls. These results indicate that blood flow may be of importance in the pathogenesis of NTG. Considering that only a limited portion of the total OA blood flow supplies the ocular system and the large inter-individual differences, a larger study or more advanced PCMRI technique might give the answer.

    Ladda ner fulltext (pdf)
    fulltext
  • 35.
    Linden, Christina
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Heijl, Anders
    Jóhannesson, Gauti
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik. Umeå universitet, Medicinska fakulteten, Wallenberg centrum för molekylär medicin vid Umeå universitet (WCMM).
    Aspberg, Johan
    Andersson Geimer, Sabina
    Bengtsson, Boel
    Initial intraocular pressure reduction by mono‐ versus multi‐therapy in patients with open‐angle glaucoma: results from the Glaucoma Intensive Treatment Study2018Ingår i: Acta Ophthalmologica, ISSN 1755-375X, E-ISSN 1755-3768, Vol. 96, nr 6, s. 567-572Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Purpose: To study newly diagnosed glaucoma patients given mono‐ or multi‐therapy regarding differences in initial intraocular pressure (IOP) reduction, target IOP levels reached and influence of untreated baseline IOP on IOP reduction.

    Methods: Patients newly diagnosed with manifest primary open‐angle glaucoma and included in the Glaucoma Intensive Treatment Study (GITS) were randomized to immediate intensive treatment with any of three different IOP‐lowering substances supplied in two bottles plus 360° laser trabeculoplasty or to conventional stepwise treatment starting with a single‐drug. Intraocular pressure reduction was analysed 1 month after initiation of treatment.

    Results: One hundred eighteen patients (143 eyes) received mono‐therapy and 122 patients (152 eyes) multi‐therapy. Median baseline IOP was 24.0 (min: 9.7, max: 56.0) mmHg in mono‐therapy eyes and 24.0 (min: 12.3, max: 48.5) mmHg in multi‐therapy eyes (p = 0.56). After 1 month in the two groups, respectively, values for median IOP reduction were 6.3 (range: −5.3–31.0) and 11.0 (range: 0.7–34.5) mmHg, and for mean relative decline 26.8 (range: −32.0–55.4) and 46.0 (range: 4.6–81.6) % (p = 0.000). A larger proportion of the multi‐therapy patients reached each target IOP level (p = 0.000). The higher the baseline IOP, the larger the observed pressure reduction, considering both absolute and relative figures. The effect was more pronounced in eyes with multi‐therapy than in those with mono‐therapy (p = 0.000). For every mmHg higher IOP at baseline, the IOP was reduced by an additional 0.56 (mono‐therapy) or 0.84 (multi‐therapy) mmHg.

    Conclusion: Intensive treatment led to considerably greater IOP reduction than mono‐therapy. Among patients with IOP ≥30 mmHg at diagnosis an IOP of <16 was reached in 2/3 of those with multi‐therapy but in none with mono‐therapy. The IOP reduction was highly dependent on the untreated IOP level.

    Ladda ner fulltext (pdf)
    fulltext
  • 36.
    Lindén, Christina
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Jóhannesson, Gauti
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Ögat2021Ingår i: Kliniska färdigheter: mötet mellan patient och läkare / [ed] Pontus Karling, Lund: Studentlitteratur AB, 2021, 4, s. 275-292Kapitel i bok, del av antologi (Övrigt vetenskapligt)
  • 37.
    Lindén, Christina
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Qvarlander, Sara
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Jóhannesson, Gauti
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Johansson, Elias
    Umeå universitet, Medicinska fakulteten, Institutionen för farmakologi och klinisk neurovetenskap, Klinisk neurovetenskap.
    Östlund, Fanny
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Malm, Jan
    Umeå universitet, Medicinska fakulteten, Institutionen för farmakologi och klinisk neurovetenskap, Klinisk neurovetenskap.
    Eklund, Anders
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Normal-Tension Glaucoma Has Normal Intracranial Pressure: A Prospective Study of Intracranial Pressure and Intraocular Pressure in Different Body Positions2018Ingår i: Ophthalmology, ISSN 0161-6420, E-ISSN 1549-4713, Vol. 125, nr 3, s. 361-368Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    PURPOSE: To test the hypothesis that normal-tension glaucoma (NTG) is caused by an increased pressure difference across the lamina cribrosa (LC) related to a low intracranial pressure (ICP).

    DESIGN: Prospective case-control study.

    PARTICIPANTS: Thirteen NTG patients (9 women; median 71 [range: 56-83] years) were recruited for investigation with the same protocol as 11 healthy volunteers (8 women; 47 [30-59] years). A larger control group (n = 51; 30 women; 68 [30-81] years) was used only for ICP comparison in supine position.

    METHODS: ICP and intraocular pressure (IOP) were simultaneously measured in supine, sitting, and 9° head-down tilt (HDT) positions. Trans-lamina cribrosa pressure difference (TLCPD) was calculated using ICP and IOP together with geometric distances estimated from magnetic resonance imaging to adjust for hydrostatic effects.

    MAIN OUTCOME MEASURES: ICP, IOP, and TLCPD in different body positions.

    RESULTS: Between NTG patients and healthy volunteers, there were no differences in ICP, IOP, or TLCPD in supine, sitting, or HDT (P ≥ 0.11), except for IOP in HDT (P = 0.04). There was no correlation between visual field defect and TLCPD, IOP, or ICP and in any body position (P ≥ 0.39). Mean ICP in supine was 10.3 mmHg (SD = 2.7) in the NTG group (n = 13) and 11.3 (2.2) mmHg in the larger control group (n = 51) (P = 0.24).

    CONCLUSIONS: There was no evidence of reduced ICP in NTG patients as compared with healthy controls, either in supine or in upright position. Consequently, the hypothesis that NTG is caused by an elevated TLCPD from low ICP was not supported.

    Ladda ner fulltext (pdf)
    fulltext
  • 38.
    Lindén, Christina
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Qvarlander, Sara
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Jóhannesson, Gauti
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Johansson, Elias
    Umeå universitet, Medicinska fakulteten, Institutionen för farmakologi och klinisk neurovetenskap, Klinisk neurovetenskap.
    Östlund, Fanny
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Malm, Jan
    Umeå universitet, Medicinska fakulteten, Institutionen för farmakologi och klinisk neurovetenskap, Klinisk neurovetenskap.
    Eklund, Anders
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Re: Linden et al.: Normal-tension glaucoma has normal intracranial pressure: a prospective study of intracranial pressure and intraocular pressure in different body positions (Ophthalmology. 2018;125:361-368) REPLY2018Ingår i: Ophthalmology, ISSN 0161-6420, E-ISSN 1549-4713, Vol. 125, nr 6, s. e43-e44Artikel i tidskrift (Refereegranskat)
  • 39.
    Lindén, Christina
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Qvarlander, Sara
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper.
    Jóhannesson, Gauti
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Johansson, Elias
    Umeå universitet, Medicinska fakulteten, Institutionen för farmakologi och klinisk neurovetenskap, Neurologi.
    Östlund, Fanny
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Malm, Jan
    Umeå universitet, Medicinska fakulteten, Institutionen för farmakologi och klinisk neurovetenskap, Neurologi.
    Eklund, Anders
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Re: Lindén et al.: Normal-tension glaucoma has normal intracranial pressure: a prospective study of intracranial pressure and intraocular pressure in different body positions (Ophthalmology.2018;125:361-368) REPLY2018Ingår i: Ophthalmology, ISSN 0161-6420, E-ISSN 1549-4713, Vol. 125, nr 10, s. e74-e75Artikel i tidskrift (Refereegranskat)
  • 40. Ohira, Akihiro
    et al.
    Hara, Katsunori
    Johannesson, Gauti
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Tanito, Masaki
    Asgrimsdottir, Gudrun Marta
    Lund, Sigrun H.
    Loftsson, Thorsteinn
    Stefansson, Einar
    Topical dexamethasone -cyclodextrin nanoparticle eye drops increase visual acuity and decrease macular thickness in diabetic macular oedema2015Ingår i: Acta Ophthalmologica, ISSN 1755-375X, E-ISSN 1755-3768, Vol. 93, nr 7, s. 610-615Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    PurposeTo compare in a randomized, controlled trial topical 1.5% dexamethasone -cyclodextrin nanoparticle eye drops (DexNP) with posterior subtenon injection of triamcinolone acetonide in diabetic macular oedema (DME). MethodsIn this prospective, randomized, controlled trial, 22 eyes of 22 consecutive patients with DME were randomized to (i) topical treatment with DexNP x3/day (4weeks), x2/day (4weeks) and x1/day (4weeks) or (ii) one posterior subtenon injection of 20mg triamcinolone acetonide. Study visits were at baseline and 4, 8, 12 and 16weeks. ResultsThe logMAR (Snellen) visual acuity (meanSD) improved significantly with DexNP from 0.41 +/- 0.3 (Snellen 0.39) to 0.32 +/- 0.25 (0.48) and 0.30 +/- 0.26 (0.50) at 4 and 8weeks, respectively. One-third of the DexNP group improved more than 0.3 logMAR units. For triamcinolone, logMAR changed significantly from 0.42 +/- 0.28 (0.38) at baseline to 0.32 +/- 0.29 (0.48) at 4w and 0.33 +/- 0.37 (0.47) at 12w. The central macular thickness (CMT) decreased significantly with DexNP from 483 +/- 141m to 384 +/- 142m at 4w and 342 +/- 114m at 8w. For triamcinolone, CMT decreased significantly at all time-points: 494 +/- 94m, 388 +/- 120, 388 +/- 145, 390 +/- 136 and 411 +/- 104m at 0, 4, 8, 12 and 16weeks, respectively. There was a modest increase in intraocular pressure (IOP) at all time-points with DexNP while no increase was seen with triamcinolone. Serum cortisol was affected by both treatments. ConclusionTopical DexNP significantly improve visual acuity and decrease macular thickness in patients with DME. The effect is similar to that from subtenon triamcinolone. A modest increase in IOP was seen with the nanoparticle eye drops, but IOP normalized after the discontinuation of treatment.

  • 41.
    Ohira, Akihiro
    et al.
    Izumo, Japan.
    Hara, Katsunori
    Izumo, Japan.
    Johannesson, Gauti
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Tanito, Masaki
    Izumo, Japan.
    Asgrimsdottir, Gudrun Marta
    Reykjavik, Iceland.
    Lund, Sigrun H.
    Reykjavik, Iceland.
    Loftsson, Thorsteinn
    Reykjavik, Iceland.
    Stefansson, Einar
    Reykjavik, Iceland.
    Topical Dexamethasone gamma-Cyclodextrin Nanoparticle Eye Drops increase Visual Acuity and decrease Macular Thickness in Diabetic Macular Edema2015Ingår i: Investigative Ophthalmology and Visual Science, ISSN 0146-0404, E-ISSN 1552-5783, Vol. 56, nr 7, artikel-id 2289Artikel i tidskrift (Övrigt vetenskapligt)
    Abstract [en]

    Purpose: To test the efficacy and safety of topical 1.5% dexamethasone γ-cyclodextrin nanoparticle eye drops (dexNP) for diabetic macular edema (DME) and compare to posterior subtenon injection of triamcinolone acetonide.

    Methods: This was a prospective, randomized controlled trial with 22 eyes in 22 consecutive patients with DME, who were randomized to a) topical treatment with dexNP eye drops x3/day for one month, x2/day the next month and finally x1/day the third month or b) one posterior subtenon injection of 20mg triamcinolone acetonide.

    Results: The central macular thickness (CMT) decreased significantly with dexNP eye drops from 483±141mm to 384±142 mm at 4 weeks and 342±114 mm at 8 weeks. For triamcinolone, CMT decreased significantly at all time points. Visual acuity (logMAR) improved significantly with dexNP eye drops from 0.41±0.3 (mean±SD) to 0.32±0.25 and 0.30±0.26 at 4 and 8 weeks respectively. One third of the eye drop group improved more than 0.3 logMAR units. For triamcinolone, logMAR changed significantly from 0.42±0.28 at baseline to 0.32±0.29 at 4 weeks and 0.33±0.37 at 12 weeks. There was a modest increase in IOP at all time points with dexNP eye drops while no increase was seen with triamcinolone. Serum cortisol was affected by both treatments.

    Conclusions: Topical dexamethasone γ-cyclodextrin nanoparticle eye drops significantly improve visual acuity and decrease macular thickness in patients with DME. The effect is similar to that from subtenon triamcinolone as well as to reports on intravitreal steroid implants and triamcinolone intravitreal injections. A modest increase in IOP was seen with the nanoparticle eye drops but IOP normalized after discontinuation of treatment.

  • 42.
    Otmani, Amin
    et al.
    Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Stockholm, Sweden.
    Jóhannesson, Gauti
    Umeå universitet, Medicinska fakulteten, Wallenberg centrum för molekylär medicin vid Umeå universitet (WCMM). Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik. Department of Ophthalmology, University of Iceland, Reykjavik, Iceland.
    Brautaset, Rune
    Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Stockholm, Sweden.
    Tribble, James R.
    Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Stockholm, Sweden.
    Williams, Pete A.
    Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Stockholm, Sweden.
    Prophylactic nicotinamide treatment protects from rotenone-induced neurodegeneration by increasing mitochondrial content and volume2024Ingår i: Acta neuropathologica communications, E-ISSN 2051-5960, Vol. 12, nr 1, artikel-id 37Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Leber’s hereditary optic neuropathy (LHON) is driven by mtDNA mutations affecting Complex I presenting as progressive retinal ganglion cell dysfunction usually in the absence of extra-ophthalmic symptoms. There are no long-term neuroprotective agents for LHON. Oral nicotinamide provides a robust neuroprotective effect against mitochondrial and metabolic dysfunction in other retinal injuries. We explored the potential for nicotinamide to protect mitochondria in LHON by modelling the disease in mice through intravitreal injection of the Complex I inhibitor rotenone. Using MitoV mice expressing a mitochondrial-tagged YFP in retinal ganglion cells we assessed mitochondrial morphology through super-resolution imaging and digital reconstruction. Rotenone induced Complex I inhibition resulted in retinal ganglion cell wide mitochondrial loss and fragmentation. This was prevented by oral nicotinamide treatment. Mitochondrial ultrastructure was quantified by transition electron microscopy, demonstrating a loss of cristae density following rotenone injection, which was also prevented by nicotinamide treatment. These results demonstrate that nicotinamide protects mitochondria during Complex I dysfunction. Nicotinamide has the potential to be a useful treatment strategy for LHON to limit retinal ganglion cell degeneration.

    Ladda ner fulltext (pdf)
    fulltext
  • 43.
    Peters, Dorothea
    et al.
    Lund University, Department of Clinical Sciences Malmö, Ophthalmology, Lund, Sweden; Department of Ophthalmology, Ophthalmology, Skåne University Hospital, Malmö, Sweden.
    Heijl, Anders
    Lund University, Department of Clinical Sciences Malmö, Ophthalmology, Lund, Sweden; Department of Ophthalmology, Ophthalmology, Skåne University Hospital, Malmö, Sweden.
    Andersson-Geimer, Sabina
    Lund University, Department of Clinical Sciences Malmö, Ophthalmology, Lund, Sweden; Department of Ophthalmology, Ophthalmology, Skåne University Hospital, Malmö, Sweden.
    Aspberg, Johan
    Lund University, Department of Clinical Sciences Malmö, Ophthalmology, Lund, Sweden; Department of Ophthalmology, Ophthalmology, Skåne University Hospital, Malmö, Sweden.
    Linden, Christina
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Jóhannesson, Gauti
    Umeå universitet, Medicinska fakulteten, Wallenberg centrum för molekylär medicin vid Umeå universitet (WCMM). Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik. Department of Ophthalmology, University of Iceland, Reykjavik, Iceland.
    Bengtsson, Boel
    Lund University, Department of Clinical Sciences Malmö, Ophthalmology, Lund, Sweden.
    Threat to fixation and vision-related quality of life in early open-angle glaucoma: results from the Glaucoma Intensive Treatment Study2023Ingår i: Acta Ophthalmologica, ISSN 1755-375X, E-ISSN 1755-3768, Vol. 101, nr 1, s. 74-80Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Purpose: To determine the effect of glaucomatous visual field (VF) damage close to the point of fixation, called threat-to-fixation (TTF), on vision-related quality of life (VRQoL) in open-angle glaucoma.

    Methods: A total of 239 patients from the Glaucoma Intensive Treatment Study (GITS) were included in this analysis. The second VF of patients with newly diagnosed primarily early glaucoma was evaluated for the presence or absence of TTF. TTF was defined as VF loss including one or more of the four innermost test points depressed at p < 1% in the total deviation probability map of Humphrey 24–2 SITA Standard visual fields. VRQoL was evaluated using Rasch-analysed National Eye Institute Visual Function Questionnaire 25 (NEI VFQ-25) scores. The correlation between VRQoL and TTF was evaluated using uni- and multivariable regression analyses.

    Results: TTF was present in at least one eye in 115 patients (48%); located in the superior hemifield alone in 47% (54 of 115), in the inferior hemifield alone in 23% (27 of 115), and in 30% (34 of 115) in both hemifields. The median Rasch-calibrated NEI VFQ-25 scores were identical when comparing patients with TTF (VRQoL score 66, 95% CI: 23–100) and those with no-TTF (VRQoL score 66, 95% CI: 21–100) (p = 0.925). Neither the presence of TTF (R2 = −0.004, = 0.968) nor the location of TTF (R2 = 0.023, = 0.103) was significantly correlated to Rasch-calibrated NEI VFQ-25 scores.

    Conclusion: The presence of TTF did not influence VRQoL, as measured by the NEI-VFQ-25, in this relatively large group of patients with mainly early glaucoma.

    Ladda ner fulltext (pdf)
    fulltext
  • 44.
    Rasmuson, Erika
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Bengtsson, Boel
    Linden, Christina
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Heijl, Anders
    Aspberg, Johan
    Andersson-Geimer, Sabina
    Jóhannesson, Gauti
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik. Umeå universitet, Medicinska fakulteten, Wallenberg centrum för molekylär medicin vid Umeå universitet (WCMM).
    Laser trabeculoplasty in newly diagnosed multi-treated glaucoma patients2021Ingår i: Acta Ophthalmologica, ISSN 1755-375X, E-ISSN 1755-3768, Vol. 99, nr 3, s. 269-274Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Purpose: To evaluate the intraocular pressure (IOP)‐lowering effect of laser trabeculoplasty (LTP) in eyes which IOP had been substantially reduced by intensive topical treatment for one week.

    Methods: Patients with newly diagnosed open‐angle glaucoma were randomized to treatment with three IOP‐lowering substances. One week later, 360° argon or selective LTP was performed. IOP was measured before LTP and at one‐, three‐, six‐ and 12‐month post‐LTP. The patients were part of the Glaucoma Intensive Treatment Study (GITS).

    Results: Mean IOP (± SD) in 152 eyes of 122 patients was 14.0 (± 3.5) mmHg just before LTP. For every mmHg higher IOP prior to LTP, the IOP was reduced by an additional 0.6 mmHg at 12 months. The IOP was significantly reduced at all follow‐up visits from −2.6 (± 3.1) mmHg at one month to −2.1 (± 3.8) mmHg at 12 months in eyes with pre‐LTP IOP ≥ 15 mmHg, while no significant IOP reduction was seen in eyes with pre‐LTP IOP < 15 mmHg. Older age, argon LTP and male sex were associated with larger IOP reduction after 12 months, whereas presence of exfoliation syndrome was associated with a smaller IOP reduction. No severe complications were reported.

    Conclusion: Success of LTP was highly dependent on the IOP level prior to LTP treatment. A sustained significant IOP reduction was seen in eyes with pre‐LTP IOP ≥ 15 mmHg whereas no such effect was seen in eyes with pre‐LTP IOP < 15 mmHg. Thus, LTP can be considered in eyes with multi‐treatment when target pressure of < 15 mmHg is not achieved.

  • 45.
    Rasmuson, Erika
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Bengtsson, Boel
    Department of Clinical Sciences in Malmö, Ophthalmology, Lund University, Malmö, Sweden.
    Linden, Christina
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Heijl, Anders
    Department of Clinical Sciences in Malmö, Ophthalmology, Lund University, Malmö, Sweden.
    Aspberg, Johan
    Department of Clinical Sciences in Malmö, Ophthalmology, Lund University, Malmö, Sweden; Department of Clinical Sciences in Malmö, Ophthalmology, Lund University, Malmö, Sweden.
    Andersson-Geimer, Sabina
    Department of Clinical Sciences in Malmö, Ophthalmology, Lund University, Malmö, Sweden; Department of Clinical Sciences in Malmö, Ophthalmology, Lund University, Malmö, Sweden.
    Jóhannesson, Gauti
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik. Umeå universitet, Medicinska fakulteten, Wallenberg centrum för molekylär medicin vid Umeå universitet (WCMM).
    Long-term follow-up of laser trabeculoplasty in multi-treated glaucoma patients2024Ingår i: Acta Ophthalmologica, ISSN 1755-375X, E-ISSN 1755-3768, Vol. 102, nr 2, s. 179-185Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Purpose: To evaluate the long-term effect of laser trabeculoplasty (LTP) in patients randomized to multi-treatment in the Glaucoma Intensive Treatment Study (GITS).

    Methods: Patients with untreated newly diagnosed open-angle glaucoma were treated with three intraocular pressure (IOP)-lowering substances for 1 week and then 360 degrees argon or selective LTP was performed. IOP was measured just before LTP and repeatedly during the 60-month study period. Our previous report on 12 months follow-up data revealed no effect of LTP in eyes having an IOP <15 mmHg before the laser treatment.

    Results: Before LTP, the mean IOP +/- standard deviation in all 152 study-eyes of 122 multi-treated patients was 14.0 +/- 3.5 mmHg. Three eyes of three deceased patients were lost to follow-up during the 60 months. After exclusion of eyes that received increased therapy during follow-up, the IOP was significantly reduced at all visits up to 48 months in eyes with pre-LTP IOP >= 15 mmHg; 2.6 +/- 3.1 mmHg at 1 month and 1.7 +/- 2.8 mmHg at 48 months, n = 56 and 48, respectively. No significant IOP reduction was seen in eyes with pre-LTP IOP <15 mmHg. Seven eyes, i.e., <13%, with pre-LTP IOP >= 15 mmHg at baseline had required increased IOP-lowering therapy at 48 months.

    Conclusion: LTP performed in multi-treated patients may provide a useful IOP reduction that is maintained over several years. This was true on a group level when the initial IOP was >= 15 mmHg, but if the pre-laser IOP was lower than that, chances of LTP success were small.

    Ladda ner fulltext (pdf)
    fulltext
  • 46.
    Rasmuson, Erika
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Linden, Christina
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Lundberg, Björn
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Jóhannesson, Gauti
    Umeå universitet, Medicinska fakulteten, Wallenberg centrum för molekylär medicin vid Umeå universitet (WCMM). Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik. Department of Ophthalmology, University of Iceland, Reykjavik, Iceland.
    Changes in intraocular pressure during the first 24 h after transscleral cyclophotocoagulation2024Ingår i: Acta Ophthalmologica, ISSN 1755-375X, E-ISSN 1755-3768Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Aims: To estimate the changes in intraocular pressure (IOP) during the first 24 h after transscleral cyclophotocoagulation (TCP).

    Methods: A prospective single-centre study, where patients with glaucoma destined for treatment with TCP were asked for participation. The IOP was measured prior to TCP and at 1, 2, 4, 6 and 24 h post-TCP. An IOP spike was defined as an elevation of IOP of ≥5 mmHg compared with baseline. The visual acuity (VA) was examined at baseline and after 24 h.

    Results: The mean IOP prior to TCP in 58 eyes of 58 patients was 26.2 (±8.9 SD) mmHg. Twenty-three eyes (40%) experienced an IOP spike at some examination timepoint during the first 24 h. The mean value of the IOP spike was 12.1 (±6.9) mmHg. Fifty-six per cent of the eyes with pseudoexfoliation glaucoma (PEXG) experienced an IOP spike, and 16% had an IOP spike ≥20 mmHg. The IOP was significantly reduced at the 24 h examination by 8.1 (±7.8) mmHg (n = 58). The VA 24 h after TCP was unchanged compared with baseline.

    Conclusion: Clinically significant IOP spikes were common in the first 24 h post-TCP. Almost one in five eyes had an increase of 10 mmHg and in almost one in 10 eyes, the IOP increase was 20 mmHg or higher. Eyes with PEXG had a higher occurrence of IOP spikes and displayed a greater magnitude of IOP elevation. Prophylactic post-operative IOP-lowering medication should be considered to prevent further glaucoma damage.

    Ladda ner fulltext (pdf)
    fulltext
  • 47.
    Rasmuson, Erika
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Linden, Christina
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Lundberg, Björn
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Jóhannesson, Gauti
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik. Umeå universitet, Medicinska fakulteten, Wallenberg centrum för molekylär medicin vid Umeå universitet (WCMM). Department of Ophthalmology, University of Iceland, Iceland.
    Changes in intraocular pressure during the first 24 hours after transscleral cyclophotocoagulationManuskript (preprint) (Övrigt vetenskapligt)
  • 48.
    Rasmuson, Erika
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Lindén, Christina
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Lundberg, Björn
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Jóhannesson, Gauti
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik. Umeå universitet, Medicinska fakulteten, Wallenberg centrum för molekylär medicin vid Umeå universitet (WCMM).
    Efficacy and safety of transscleral cyclophotocoagulation in Swedish glaucoma patients2019Ingår i: Acta Ophthalmologica, ISSN 1755-375X, E-ISSN 1755-3768, Vol. 97, nr 8, s. 764-770Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Purpose: To retrospectively evaluate the efficacy and safety of all transscleral cyclophotocoagulation (TCP) treatments performed during a 5-year period.

    Methods: Medical records of all patients, who had undergone TCP treatment between 2010 and 2014 at Umea University Hospital, Sweden, were evaluated. Clinical data including intraocular pressure (IOP), visual acuity (VA), number of topical glaucoma medications, use of oral acetazolamide, retreatments and complications during a 2-year follow-up were registered. Global success was defined as IOP 6-18 mmHg with or without glaucoma medication. 

    Results: Three hundred patients underwent TCP during the time period. Mean IOP at baseline was 29.3 11.0 (mean +/- standard deviation) mmHg (n = 297) with a mean reduction of 11.5 (+/- 12.0) mmHg at 1 year (n = 258; p < 0.001) and 12.6 (<plus/minus>12.0) mmHg at 2-year follow-up (n = 245; p < 0.001). Global success at 2 years was 64%, achieved by a mean of 1.2 treatments (n = 257). The number of topical glaucoma medications at baseline was 3.1 (<plus/minus>1.0; n = 296) and was reduced by 0.9 (+/- 1.0) medications at 2 years (n = 244; p < 0.001). Use of oral acetazolamide decreased from 30% (n = 90) at baseline to 5.3% (n = 13) at 2 years. In eyes with Snellen VA <greater than or equal to> 0.1, the mean VA at baseline was 0.55 (+/- 0.3) logarithm of the minimum angle of resolution (logMAR; n = 132) and 1.1 (+/- 0.9) logMAR (n = 76) at 2 years (p < 0.001). No cases of phthisis bulbi were found.

    Conclusion: This study displays a substantial and long-term reduction of IOP following TCP with a decrease in topical and oral glaucoma medications. The treatment appears to be safe but the decrease in VA during follow-up is a concern that needs further evaluation.

  • 49.
    Rutigliani, Carola
    et al.
    Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Stockholm, Sweden.
    Tribble, James R.
    Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Stockholm, Sweden.
    Hagström, Anna
    Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Stockholm, Sweden.
    Lardner, Emma
    Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Stockholm, Sweden; St. Erik Eye Hospital, Stockholm, Sweden.
    Jóhannesson, Gauti
    Umeå universitet, Medicinska fakulteten, Wallenberg centrum för molekylär medicin vid Umeå universitet (WCMM). Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Stålhammar, Gustav
    Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Stockholm, Sweden; St. Erik Eye Hospital, Stockholm, Sweden.
    Williams, Pete A.
    Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Stockholm, Sweden.
    Widespread retina and optic nerve neuroinflammation in enucleated eyes from glaucoma patients2022Ingår i: Acta neuropathologica communications, E-ISSN 2051-5960, Vol. 10, nr 1, artikel-id 118Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Neuroinflammation is recognized as a key component of neurodegenerative disease. In glaucoma, a common neurodegenerative disease and the leading cause of irreversible blindness, the evidence for neuroinflammation in patients is lacking. Animal models have demonstrated significant pro-inflammatory activation of resident glia in the retina, as well as influx of blood-derived monocytes and pro-inflammatory factors. Confirmation of this in human donor tissue has been challenging due to a lack of well-preserved and well-characterized post-mortem tissue. To address this we utilize archived, wax embedded eyes fixed immediately following enucleation from living glaucoma patients. We compared glaucoma to control eyes (enucleated for uveal melanoma where the tumor did not impact the central retina or optic nerve). We performed immunolabelling for neurodegenerative and glial markers (CD45, CD163, IBA1, GFAP, Vimentin) which were quantified by high-resolution light microscopy and image analysis in FIJI. Glaucoma eyes demonstrated significant neural loss consistent with advanced neurodegeneration. IBA1 and GFAP were significantly increased in the retina and optic nerve head of the glaucomatous eyes indicating that significant neuroinflammation had occurred which support findings in animal models. Inflammation is a treatable symptom of many diseases and as such, identification of earlier inflammatory processes in glaucoma could be important for potential future treatment options.

    Ladda ner fulltext (pdf)
    fulltext
  • 50. Shulman, Shiri
    et al.
    Jóhannesson, Gauti
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    Stefánsson, Einar
    Loewenstein, Anat
    Rosenblatt, Amir
    Habot-Wilner, Zohar
    Topical dexamethasone-cyclodextrin nanoparticle eye drops for non-infectious Uveitic macular oedema and vitritis: a pilot study2015Ingår i: Acta Ophthalmologica, ISSN 1755-375X, E-ISSN 1755-3768, Vol. 93, nr 5, s. 411-415Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Purpose: To evaluate the safety and efficacy of 1.5% dexamethasone nanoparticle (DexNP) drops in eyes with non-infectious uveitic macular oedema and vitritis. Methods: In a prospective pilot study, DexNP drops were administered four times a day for 4 weeks followed by drops tapering over a period of another 4 weeks. Follow-up time was 12 weeks. Results: Five eyes with macular oedema and three eyes with vitritis were included in the study. Best corrected visual acuity (BCVA) significantly improved from a median of 0.2 logMAR to a median of 0.15 logMAR at 4 weeks' time (p<0.05). Median BCVA was 0.175 logMAR and 0.2 logMAR, at week 8 and 12, respectively (p>0.05). Macular oedema significantly improved at all time-points as compared to baseline (p<0.05) and resolved in all eyes during follow-up. One eye had macular oedema relapse at week 12. Vitritis improved in all eyes and resolved completely in two eyes. One eye had intraocular pressure (IOP) elevation which was well controlled with topical antihypertensive treatment, and one eye had cataract progression. Conclusion: This short pilot study demonstrates favourable effect of 1.5% DexNP eye drops on eyes with non-infectious uveitic macular oedema and vitritis. Further comparative long-term studies are warranted to assess this effect.

12 1 - 50 av 51
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf