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Jóhannesson, Gauti
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Publications (10 of 30) Show all publications
Kristiansen, M., Linden, C., Qvarlander, S., Wåhlin, A., Ambarki, K., Hallberg, P., . . . Jóhannesson, G. (2018). Blood flow rate of ophthalmic artery in patients with normal tension glaucoma and healthy controls. Paper presented at Annual Meeting of the Association-for-Research-in-Vision-and-Ophthalmology (ARVO), APR 29-MAY 03, 2018, Honolulu, HI. Investigative Ophthalmology and Visual Science, 59(9)
Open this publication in new window or tab >>Blood flow rate of ophthalmic artery in patients with normal tension glaucoma and healthy controls
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2018 (English)In: Investigative Ophthalmology and Visual Science, ISSN 0146-0404, E-ISSN 1552-5783, Vol. 59, no 9Article in journal, Meeting abstract (Other academic) Published
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.

Place, publisher, year, edition, pages
The Association for Research in Vision and Ophthalmology, 2018
National Category
Ophthalmology
Identifiers
urn:nbn:se:umu:diva-152420 (URN)000442932805099 ()
Conference
Annual Meeting of the Association-for-Research-in-Vision-and-Ophthalmology (ARVO), APR 29-MAY 03, 2018, Honolulu, HI
Funder
Swedish Society for Medical Research (SSMF)The Swedish Medical Association
Available from: 2018-10-05 Created: 2018-10-05 Last updated: 2018-10-08Bibliographically approved
Linden, C., Heijl, A., Jóhannesson, G., Aspberg, J., Andersson Geimer, S. & Bengtsson, B. (2018). Initial intraocular pressure reduction by mono‐ versus multi‐therapy in patients with open‐angle glaucoma: results from the Glaucoma Intensive Treatment Study. Acta Ophthalmologica, 96(6), 567-572
Open this publication in new window or tab >>Initial intraocular pressure reduction by mono‐ versus multi‐therapy in patients with open‐angle glaucoma: results from the Glaucoma Intensive Treatment Study
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2018 (English)In: Acta Ophthalmologica, ISSN 1755-375X, E-ISSN 1755-3768, Vol. 96, no 6, p. 567-572Article in journal (Refereed) Published
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.

Place, publisher, year, edition, pages
John Wiley & Sons, 2018
Keywords
baseline pressure, intraocular pressure, multi-therapy, open-angle glaucoma, target pressure, therapy
National Category
Ophthalmology
Identifiers
urn:nbn:se:umu:diva-153137 (URN)10.1111/aos.13790 (DOI)000447257100004 ()30242986 (PubMedID)
Available from: 2018-11-08 Created: 2018-11-08 Last updated: 2018-11-08Bibliographically approved
Jóhannesson, G., Eklund, A. & Linden, C. (2018). Intracranial and Intraocular Pressure at the Lamina Cribrosa: Gradient Effects. Current Neurology and Neuroscience Reports, 18(5), Article ID 25.
Open this publication in new window or tab >>Intracranial and Intraocular Pressure at the Lamina Cribrosa: Gradient Effects
2018 (English)In: Current Neurology and Neuroscience Reports, ISSN 1528-4042, E-ISSN 1534-6293, Vol. 18, no 5, article id 25Article, review/survey (Refereed) Published
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.

Place, publisher, year, edition, pages
SPRINGER, 2018
Keywords
Translamina cribrosa pressure difference, Translaminar pressure difference, Cerebrospinal fluid, Intracranial pressure, Intraocular pressure, Normal tension
National Category
Ophthalmology
Identifiers
urn:nbn:se:umu:diva-150706 (URN)10.1007/s11910-018-0831-9 (DOI)000430797500004 ()29651628 (PubMedID)2-s2.0-85045399299 (Scopus ID)
Available from: 2018-09-03 Created: 2018-09-03 Last updated: 2018-09-03Bibliographically approved
Aspberg, J., Heijl, A., Jóhannesson, G., Linden, C., Andersson-Geimer, S. & Bengtsson, B. (2018). Intraocular Pressure Lowering Effect of Latanoprost as First-line Treatment for Glaucoma. Journal of glaucoma, 27(11), 976-980
Open this publication in new window or tab >>Intraocular Pressure Lowering Effect of Latanoprost as First-line Treatment for Glaucoma
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2018 (English)In: Journal of glaucoma, ISSN 1057-0829, E-ISSN 1536-481X, Vol. 27, no 11, p. 976-980Article in journal (Refereed) Published
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.

Place, publisher, year, edition, pages
Lippincott Williams & Wilkins, 2018
Keywords
open-angle glaucoma, latanoprost, intraocular pressure, IOP, IOP reduction
National Category
Ophthalmology
Identifiers
urn:nbn:se:umu:diva-153969 (URN)10.1097/IJG.0000000000001055 (DOI)000449638900011 ()30113517 (PubMedID)
Funder
Region SkåneVästerbotten County Council
Available from: 2018-12-10 Created: 2018-12-10 Last updated: 2019-01-14Bibliographically approved
Lindén, C., Qvarlander, S., Jóhannesson, G., Johansson, E., Östlund, F., Malm, J. & Eklund, A. (2018). Normal-Tension Glaucoma Has Normal Intracranial Pressure: A Prospective Study of Intracranial Pressure and Intraocular Pressure in Different Body Positions. Ophthalmology (Rochester, Minn.), 125(3), 361-368
Open this publication in new window or tab >>Normal-Tension Glaucoma Has Normal Intracranial Pressure: A Prospective Study of Intracranial Pressure and Intraocular Pressure in Different Body Positions
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2018 (English)In: Ophthalmology (Rochester, Minn.), ISSN 0161-6420, E-ISSN 1549-4713, Vol. 125, no 3, p. 361-368Article in journal (Refereed) Published
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.

National Category
Ophthalmology
Identifiers
urn:nbn:se:umu:diva-142423 (URN)10.1016/j.ophtha.2017.09.022 (DOI)000425377300015 ()29096996 (PubMedID)
Funder
Swedish Research Council, 2015-05616
Available from: 2017-11-30 Created: 2017-11-30 Last updated: 2018-06-21Bibliographically approved
Lindén, C., Qvarlander, S., Jóhannesson, G., Johansson, E., Östlund, F., Malm, J. & Eklund, A. (2018). 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) REPLY [Letter to the editor]. Ophthalmology (Rochester, Minn.), 125(6), e43-e44
Open this publication in new window or tab >>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) REPLY
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2018 (English)In: Ophthalmology (Rochester, Minn.), ISSN 0161-6420, E-ISSN 1549-4713, Vol. 125, no 6, p. e43-e44Article in journal, Letter (Refereed) Published
Place, publisher, year, edition, pages
Elsevier, 2018
National Category
Ophthalmology
Identifiers
urn:nbn:se:umu:diva-148825 (URN)10.1016/j.ophtha.2018.01.006 (DOI)000432371600007 ()29784104 (PubMedID)
Note

Refers to: Baartman B, Sudhagoni R, Swan R, Greenwood M, Berdahl, J. 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) DOI: 10.1016/j.ophtha.2017.09.022

Available from: 2018-06-21 Created: 2018-06-21 Last updated: 2018-11-06Bibliographically approved
Lindén, C., Qvarlander, S., Jóhannesson, G., Johansson, E., Östlund, F., Malm, J. & Eklund, A. (2018). 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) REPLY [Letter to the editor]. Ophthalmology (Rochester, Minn.), 125(10), E74-E75
Open this publication in new window or tab >>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) REPLY
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2018 (English)In: Ophthalmology (Rochester, Minn.), ISSN 0161-6420, E-ISSN 1549-4713, Vol. 125, no 10, p. E74-E75Article in journal, Letter (Refereed) Published
Place, publisher, year, edition, pages
Elsevier, 2018
National Category
Ophthalmology
Identifiers
urn:nbn:se:umu:diva-152382 (URN)10.1016/j.ophtha.2018.04.028 (DOI)000445012100008 ()30243346 (PubMedID)
Note

Refers to: Baartman B, Sudhagoni R, Swan R, Greenwood M, Berdahl, J. 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) DOI: 10.1016/j.ophtha.2017.09.022

Available from: 2018-11-01 Created: 2018-11-01 Last updated: 2018-11-06Bibliographically approved
Bengtsson, B., Heijl, A., Jóhannesson, G., Andersson-Geimer, S., Aspberg, J. & Linden, C. (2018). The Glaucoma Intensive Treatment Study (GITS), a randomized clinical trial: design, methodology and baseline data. Acta Ophthalmologica, 96(6), 557-566
Open this publication in new window or tab >>The Glaucoma Intensive Treatment Study (GITS), a randomized clinical trial: design, methodology and baseline data
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2018 (English)In: Acta Ophthalmologica, ISSN 1755-375X, E-ISSN 1755-3768, Vol. 96, no 6, p. 557-566Article in journal (Refereed) Published
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.

Place, publisher, year, edition, pages
John Wiley & Sons, 2018
Keywords
drug trial, glaucoma, quality of life, visual field
National Category
Ophthalmology
Identifiers
urn:nbn:se:umu:diva-153139 (URN)10.1111/aos.13791 (DOI)000447257100003 ()30171664 (PubMedID)
Available from: 2018-11-07 Created: 2018-11-07 Last updated: 2018-11-07Bibliographically approved
Johannesson, G., Shulman, S., Ruckert, R. & Stefansson, E. (2017). In Vivo Visualization of Large Choroidal Vessels Obliteration in Geographic Atrophy [Letter to the editor]. Retina, 37(2), E24-E24
Open this publication in new window or tab >>In Vivo Visualization of Large Choroidal Vessels Obliteration in Geographic Atrophy
2017 (English)In: Retina, ISSN 0275-004X, E-ISSN 1539-2864, Vol. 37, no 2, p. E24-E24Article in journal, Letter (Refereed) Published
National Category
Ophthalmology
Identifiers
urn:nbn:se:umu:diva-132634 (URN)000393671400008 ()28060149 (PubMedID)
Available from: 2017-03-20 Created: 2017-03-20 Last updated: 2018-06-09Bibliographically approved
Jóhannesson, G., Stefánsson, E. & Loftsson, T. (2016). Microspheres and Nanotechnology for Drug Delivery. Developments in ophthalmology, 55, 93-103
Open this publication in new window or tab >>Microspheres and Nanotechnology for Drug Delivery
2016 (English)In: Developments in ophthalmology, ISSN 1662-2790, Vol. 55, p. 93-103Article in journal (Refereed) Published
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.

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:umu:diva-117371 (URN)10.1159/000434693 (DOI)26501994 (PubMedID)
Available from: 2016-02-29 Created: 2016-02-29 Last updated: 2018-06-07Bibliographically approved
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