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Purpose: To study the frequency over time and outcome of penetrating keratoplasty (PK), "keratoplasty à chaud," in patients with infectious keratitis with 2-year follow-up data.

Methods: This register-based study included keratitis cases that had undergone PK in Sweden between 2001 and 2020 and reported to the Swedish Corneal Transplant Register.

Results: During the study period, 69 eyes were subjected to acute PK due to progressive infectious keratitis. The number increased from 2 annual procedures in the first half of the study period to 5 in the second half (P = 0.01). Preoperative corneal perforation was present in 43.5% (n = 30) of the eyes. Two years after surgery, follow-up data were completed in the register for 53 eyes; of these, 62.3% (n = 33) were considered to have functioning grafts, and 20.8% (n = 11) had experienced a rejection episode. The visual acuity improved from hand motion to counting fingers (P = 0.002), and the proportion of eyes with a visual acuity of ≤1.0 logMAR increased from 5.7% (n = 3) before the surgery to 45.3% (n = 24) at the 2-year follow-up (P < 0.001).

Conclusions: The number of active infectious keratitis cases undergoing keratoplasty à chaud increased in Sweden during the 21st century. Most of the cases were successful regarding the structural integrity of the bulb, that is, "had a saved eye" and even a functioning graft 2 years after corneal transplantation. The visual gain was distinct, albeit modest. In cases with severe infectious keratitis, and even a concomitant perforation in the cornea due to the infection, corneal transplantation should continue to be an option.

Purpose: This cross-sectional survey study aimed to explore the phacoemulsification techniques among Swedish cataract surgeons, and investigate the association between technique preferences and surgical outcomes, particularly posterior capsular rupture (PCR).

Methods: A survey questionnaire was responded by 170 cataract surgeons and data from 192 494 cases, linked to the surgeons, were analysed from the Swedish National Cataract Registry (SNCR) for 2021–2022. Surgeons' demographic characteristics, surgical techniques and complications were assessed. Associations between surgical technique preferences and outcomes were analysed with binary logistic regression.

Results: The chopping technique (stop and chop or direct chop) was favoured by 64.6% of surgeons, followed by divide and conquer (32.4%), and tilt and tumble (7.6%). Surgeons' annual caseloads varied widely (range 11–2687). No significant correlation was found between technique preference and PCR rates, which was consistently 0.5%–0.6% in all groups, except for a trend suggesting reduced risk with tilt and tumble. Mentoring activity (35.0%) and public surgical setting (40.3%) was highest in the direct chop group. Notably, 75% of the surgeries were performed by surgeons with more than 10 years' experience. Confounding factors, such as high-volume surgeons having a low frequency of complications, have been accounted for in a logistic regression.

Conclusion: This study provides insights into cataract surgery practices in Sweden and suggests that surgeons can choose their preferred approach without significantly affecting complication rates. This research also underscores the need for continued exploration of surgical practices and their impact on patient outcomes, particularly in the case of the tilt and tumble technique, which is less commonly employed.

Purpose: To study the prioritization effects of the of COVID-19 pandemic on Swedish cataract surgery using a national healthcare registry with high coverage.

Setting: A study from the Swedish National Cataract Register (NCR), involving all patients undergoing cataract surgery in Sweden during 2019–2022 – before, during and after the COVID-19 pandemic.

Results: With the pandemic outbreak, the number of cataract surgeries fell by 22% in 2020 (15 369 procedures), albeit with large regional differences (−43% to +58%). The numbers recovered in 2021, and in 2022, a new top notation was seen (n = 149 952). On a national level, the patients were younger (−0.46 years, p < 0.001), with a larger proportion of less difficult cases (p < 0.001) and the proportion of males was higher (p < 0.001) during the pandemic, but all these variables also differed substantially between different regions and clinics.

Conclusion: A national registry with high coverage can map the consequences of an event disrupting elective surgery in detail. During the COVID-19 pandemic, the impact on Swedish cataract surgery varied largely between different regions, clinics, and healthcare providers, leading to inequality in the availability of surgery. These differences likely owed to variations in healthcare policy approaches in different parts of the country. The present study shows that outcomes at one clinic or region cannot be extrapolated to larger regions under these circumstances. It actualizes the need to aim for a healthcare on equal terms, but it also shows a system that delivers care to many despite difficult times.

Fuchs endothelial corneal dystrophy (FECD) is caused by a corneal endothelial cell loss, leading to corneal edema and visual impairment. The most significant genetic risk factor for FECD is an expansion of the CTG18.1 locus in transcription factor 4 (TCF4). The current treatment for severe FECD is corneal transplantation, with Descemet stripping automated keratoplasty (DSAEK) as a common surgical method. Although successful in most cases, the risk for transplant failure due to diverse causes must be considered. In this study, we investigated if presence of TCF4 CTG18.1 expansion with more than 31 (n ≥ 31) repeats in donated corneal grafts could be a reason for corneal transplant failure after DSAEK. For this, nine consecutively failed DSAEK corneal grafts were genotyped for CTG18.1 repeat length. One-sided Mann–Whitney U test was performed to evaluate if failed DSAEK corneal grafts had longer CTG18.1 repeats than healthy controls from the same population. All failed corneal grafts had CTG18.1 n ≤ 27 with a median of 18 (IQR 8.0) repeats for the longest allele. There was no statistical difference in CTG18.1 repeat lengths between failed corneal grafts and the geographically matched healthy control group. In conclusion, none of the nine failed corneal grafts in our material had CTG18.1 repeat lengths ≥ 31, a cut-off known to have a biological relevance in FECD. Thus, our results suggest that the assessment of donors and inspection of the corneal tissue before the decision for procurement is sufficient, in terms of recognizing FECD in the donor.

Purpose: To analyse clinical characteristics and risk factors for post-operative endophthalmitis (POE) in a Swedish patient insurance database and compare prevalence of POE with two national quality registers. Methods: We analysed 218 medical records of patients who claimed compensation for POE following ocular surgery from 2010 to 2020. The data were cross-referenced with national quality registers.

Results: In total, 189 of 218 patients presented with severe ocular inflammation with no visibility into the posterior fundus and 160 of 218 had hypopyon. After treatment, the best corrected visual acuity improved from 2.4 to 1.8 LogMAR in mean (p < 0.01). Poorer visual outcome was associated with POE caused by Staphylococcus aureus, Enterococcus faecalis, and Streptococcus infections, as compared to coagulase-negative staphylococci (p < 0.01). Retinal detachment was linked to worse visual prognosis (p = 0.01). Eighteen patients required enucleation or evisceration, three of these had initially undergone vitrectomy, compared with 124 of 200 where the eyes were preserved. Peripheral vitrectomy showed better outcome compared to central vitrectomy (p = 0.02). Financial compensation was granted for 92 % of patients. However, a discrepancy was noted when comparing the number of patients with insurance claims to those reported by the national quality registers, indicating underreporting in both.

Conclusion: This study highlights the impact of bacterial type on visual recovery in POE. Peripheral vitrectomy showed better outcomes than central vitrectomy. Most patients needing enucleation or evisceration were not treated with vitrectomy. Significant discrepancies were found between POE prevalence in quality registers and insurance reports, indicating the need for better reporting, though the exact magnitude of underreporting remains unclear.

Objective: To evaluate the effects of customized corneal collagen cross-linking (CXL) on higher-order aberrations (HOAs) in keratoconus (KC): vertical coma (VC), horizontal coma (HC), spherical aberration (SA), trefoil (TF) and astigmatism, compared with the same effects in healthy eyes undergoing CXL for low-grade myopia.

Methods: This mixed-designed study included 38 eyes of 38 patients with KC, treated and followed prospectively, who received customized epi-on CXL in high oxygen, and a retrospective control group of 23 eyes from 23 patients who underwent central 4-mm CXL treatment for low-grade myopia. VC, HC, SA, TF and keratometry values were obtained from Pentacam HR® measurements at baseline and at 1, 6, 12 and 24 months post-treatment. Statistical analyses included paired T-tests for changes over time and Pearson correlation tests to assess relationships between aberrations, best spectacle-corrected and low-contrast visual acuities (BSCVA and LCVA, respectively) and CXL parameters.

Results: Reduced HOAs and improved visual acuities were observed in KC. A 20% reduction in VC was observed at 24 months (from −1.82 ± 1.15 μm to −1.46 ± 1.01 μm; 95% CI: [0.155, 0.629], p = 0.002), while a 17% reduction in HC was observed at 12 months (from −0.35 ± 0.56 μm to −0.29 ± 0.62 μm; 95% CI: [0.003, 0.096], p = 0.037). A positive correlation was found between baseline VC and the level of improvement in VC at 24 months (R2 = 0.200, p = 0.015). SA increased by 126% at 24 months (from −0.21 ± 0.62 μm to 0.054 ± 0.52 μm; 95% CI: [0.143, 0.347], p ≤ 0.001). TF and astigmatism did not alter from the treatment. In myopia, the natural positive SA increased by 57% post-treatment (from 0.14 ± 0.061 μm to 0.22 ± 0.076 μm at 24 months; 95% CI: [0.067, 0.098], p ≤ 0.001), while changes in VC and HC were minor and BSCVA remained stable.

Conclusion: Customized CXL effectively reduces HOAs in KC. For VC the improvement is larger in cases with higher preoperative VC, indicating that the concept of customization has its intended effect. Accordingly, SA and visual acuities improve in KC whereas CXL for low-grade myopia tends to increase corneal SA unfavourably.

Purpose: To study the trend of delayed sequential bilateral cataract surgery (DSBCS) in Sweden in the past decade.

Methods: This register-based cohort study utilized data from the Swedish National Cataract Register (NCR) from 2010 through 2019. Register files from patients who underwent cataract surgery in both eyes during the study period were linked using their social security numbers. Bilateral surgeries on different days were classified as DSBCS. The study investigated the association between DSBCS within 3 months and several variables with stratification and multivariate logistic regression. The following variables were used: operation year, region, private or public unit, age, sex, indication for surgery, type of intraocular lens (IOL), preoperative visual acuity, ocular comorbidity, posterior capsule rupture and perioperative difficulties.

Results: During the study period, 368,106 patients underwent DSBCS, of which 62.6% (n = 230,331) had bilateral surgery within 3 months. The median time between the surgeries was 61 days (interquartile range 26–161 days), showing regional variations. Better visual acuity in the fellow eye, presence of ocular comorbidity, various perioperative events and complications were associated with longer time to surgery of the second eye. Conversely, cataract surgery in more recent years, private clinic, increasing age, anisometropia and multifocal IOL were associated with shorter timespan between surgeries.

Conclusions: The majority of DSBCS were conducted within a 3-month timeframe, with the interval between surgeries decreasing throughout the study period. Several rational factors were associated with the time difference, in addition to regional variations. Many patients would probably benefit from less time between the surgeries, and we encourage a clinical practice taking the whole patient’s visual function into account.

Purpose: To analyse trends of ISBCS reported to the Swedish National Cataract Register (NCR) over a 10-year period.

Methods: Since 2010 the NCR contains social security number of all individuals in the list of parameters reported to NCR after each cataract procedure. Bilateral surgeries were mapped out using social security numbers. When dates of both-eye surgeries are identical for an individual it is classified as an immediate sequential bilateral cataract surgery (ISBCS). This study includes all data reported during the period 1st of January 2010 to 31st of December 2019. During the study period 113 cataract surgery clinics affiliated to the NCR reported their data on consecutive cataract cases.

Results: For the whole period 54 194 ISBCS were reported. The total number of bilateral cataract extractions was 422 300. There was a significant trend of increasing ISBCS over time with linear regression (Beta = 1.75, p < 0.001). In ISBCS the occurrence of an ocular comorbidity decreased over time. The use of a capsular tension ring was significantly more common in ISBCS than in delayed sequential bilateral cataract surgery (DSBCS). All other measures taken during surgery were more common in DSBCS. The use of multifocal IOL was significantly more frequent in ISBCS compared to DSBCS (p < 0.001).

Conclusions: The use of ISBCS has increased over the study period. The operated eyes have less risk factors than eyes going through a DSBCS, but both ocular comorbidities and surgical complications occur in ISBCS eyes.

Purpose: To analyse the temperature of the corneal surface in keratoconus during corneal customized crosslinking (CXL) with a preserved epithelium (epi-on) under oxygen flow, and epi-off CXL in room air, and to assess the effect of pre-heating the oxygen.

Methods: This masked, intra-individual comparing randomized study included 14 participants with bilateral progressive keratoconus treated with bilateral CXL: one eye with epi-on CXL under a flow of 2.5 L/min oxygen; the fellow eye with epi-off CXL in room air. In a second setting involving 12 healthy participants, room-tempered oxygen was flushed over one eye and oxygen pre-heated to 37°C over the fellow eye. The corneal surface temperature was assessed with infrared photography.

Results: A reduction in corneal surface temperature was seen from the pre-treatment application of topical riboflavin in the epi-off group (−1.1 ± 1.0°C, p < 0.001). The temperature increased during the first half of the CXL treatment in both groups (+0.7 ± 1.2°C, p = 0.041 for epi-on; +0.7 ± 0.9°C, p = 0.023 for epi-off CXL, respectively). In epi-on CXL an overall temperature increase was seen during the treatment (+0.8 ± 1.2°C, p = 0.016). In the second setting, pre-heating the oxygen rendered a surface temperature increase of +1.8 ± 0.2°C (p < 0.001).

Conclusion: In epi-off CXL, the application of topical room-tempered riboflavin decreases the corneal surface temperature, likely due to increased evaporation. A slight temperature increase is seen during CXL with both epi-on and epi-off CXL, albeit far below the corneal safety limit. The corneal temperature can, however, be increased by applying pre-heated oxygen, a possible approach to modify or augment the treatment effect in CXL.

Purpose: To investigate the surgical and pharmacological management and outcomes of patients with cataract and concurrent uveitis.

Methods: Data from the Swedish National Cataract Register, 2018–2019, were collected and analysed. Uveitic eyes were identified and eyes without uveitis were used as controls. Generalized estimating equations were used to adjust for intra-individual correlation.

Results: The study included 719 eyes with and 256 360 without uveitis. The mean age was 66.0 ± 13.5 (standard deviation [SD]) years in the uveitis group and 74.3 ± 8.7 years in the control group (p < 0.001). Surgery was associated with more intraoperative difficulties in eyes with uveitis (27.0%) than in control eyes (7.1%; p < 0.001). Posterior capsule rupture/zonular complications were registered in nine eyes with uveitis (1.3%) and in 1464 eyes without uveitis (0.6%; p = 0.02). Hydrophilic acrylic intraocular lenses (uveitis 3.6%, controls 1.2%) and subconjunctival steroids (uveitis 17.4%, controls 6.1%) were more frequently used in eyes with uveitis (p < 0.001). post-operative best-corrected visual acuity (BCVA) was 0.16 ± 0.38 logarithm of the minimum angle of resolution (logMAR, mean ± SD) in eyes with uveitis (n = 52) and 0.08 ± 0.20 in control eyes (n = 14 489; p = 0.008).

Conclusion: In this large registry-based Swedish cohort study, the findings demonstrate that cataract surgery in patients with uveitis poses more challenges and requires special surgical precautions. Eyes with concurrent uveitis had worse BCVA prior to and following surgery. Despite the intraoperative challenges, the visual improvement was greater in the uveitic group.