[2.6 million cataract surgeries: 31 years with the Swedish National Cataract Register 1992-2022]. / 2,6 miljoner kataraktoperationer.

This review summarizes data collected by the Swedish National Cataract Register (NCR), which by the end of 2022 contained data on more than 2.6 million cataract surgeries between 1992-2022. During these 31 years, the cataract surgery rate (CSR) rose from 3 700 to 14 407. The coverage of NCR is very high, including 93% of all cataract procedures in Sweden during the last decade. A clear trend is that the procedure is performed in eyes with increasingly high visual acuity. The proportion of patients with Snellen 0.5 or worse in the first eye at surgery has decreased from 88% in 2007 to 69% in 2022. Patient Reported Outcome Measures (PROM) have been registered with the Catquest-9SF questionnaire since 2008, demonstrating stable favorable outcomes. Surgical complications have decreased; endophthalmitis has decreased from 0.10% to below 0.02%, and posterior capsule rupture from 2.8% to 0.6%.

CTG18.1 expansion in transcription factor 4 (TCF4) in corneal graft failure: preliminary study.

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.

Ten-year trends of immediate sequential bilateral cataract surgery (ISBCS) as reflected in the Swedish National Cataract Register.

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.

Thermographic analysis of the corneal surface in epi-on and epi-off corneal crosslinking for keratoconus.

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.

Descemet Stripping Automated Endothelial Keratoplasty versus Descemet Membrane Endothelial Keratoplasty for Fuchs Endothelial Corneal Dystrophy: A National Registry-Based Comparison.

PURPOSE: To compare the outcome between posterior lamellar corneal transplant procedures for Fuchs endothelial corneal dystrophy, taking preoperative patient characteristics in consideration. Surgical methods compared were Descemet membrane endothelial keratoplasty (DMEK), Descemet stripping automated endothelial keratoplasty (DSAEK), and DSAEK with concomitant cataract surgery (phacoemulsification plus DSAEK). DESIGN: Registry-based study with propensity score matching. PARTICIPANTS: One thousand six hundred seventy-seven patients from all Swedish corneal transplantation units treated from 2012 through 2019. METHODS: All patients undergoing endothelial keratoplasty performed from 2012 through 2019 with completed 2-year follow-up data reported to The Swedish Corneal Transplant Register were included, totaling 1677 patients. Three comparable groups (DMEK, DSAEK, and phacoemulsification plus DSAEK) with 216 patients in each group were generated with propensity score matching based on preoperative visual acuity, age, sex, year of surgery, and preoperative risk factors such as inflammation, vascularization, and glaucoma. MAIN OUTCOME MEASURES: Best-corrected visual acuity (BCVA) at the 2-year follow-up, frequency of graft dislocation, graft rejection episodes, and graft failure within 2 years including primary graft failure. RESULTS: The preoperative corneal status was affected more severely in the DSAEK group before matching. In the matched groups, the median BCVA 2 years after surgery was 0.1 logarithm of the minimum angle of resolution (logMAR) in both the DMEK and the phacoemulsification plus DSAEK groups and 0.15 logMAR in the DSAEK group (P = 0.001). The frequency of graft dislocation was higher among the patients undergoing phacoemulsification plus DSAEK, but the frequency of graft failure and primary graft failure was higher in the DMEK group. CONCLUSIONS: Visual acuity improved in most patients (90%) with all 3 surgical methods. However, DMEK and phacoemulsification plus DSAEK reached higher levels of visual acuity 2 years after surgery, and phacoemulsification plus DSAEK was superior considering graft survival rate. All 3 surgical procedures showed both strengths and weaknesses, suggesting that the choice of surgical method should be individualized, taking into consideration not only the cornea, but each patient's complete medical status as well as the entire course of postoperative medical care. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Two point four million cataract surgeries: 30 years with the Swedish National Cataract Register, 1992-2021.

The present review summarizes data collected by the Swedish National Cataract Register (NCR), which by the end of 2021 contained data for more than 2.4 million cataract surgeries between 1992 and 2021. During these 30 years, the cataract surgery rate rose from 3700 to 12 800. The coverage of NCR is very high including 93% of all cataract procedures in Sweden between 2010 and 2021. Independently of demographic changes, the proportion of operations of patients age 60 to 79 has increased while the proportion of 80 to 90+ has decreased. The median visual acuity of the first eye planned for surgery was 0.1 decimal in 1992 and has increased to 0.5 decimal in 2021. Patient-reported outcome measures have been registered with the Catquest-9SF questionnaire since 2008, demonstrating intervention at an earlier stage, but consistently favorable outcomes. Surgical complications have decreased; endophthalmitis has decreased from 0.10% to below 0.02%, and posterior capsule rupture from 2.8% to 0.6%.

DNA methylation changes and increased mRNA expression of coagulation proteins, factor V and thrombomodulin in Fuchs endothelial corneal dystrophy.

Late-onset Fuchs endothelial corneal dystrophy (FECD) is a disease affecting the corneal endothelium (CE), associated with a cytosine-thymine-guanine repeat expansion at the CTG18.1 locus in the transcription factor 4 (TCF4) gene. It is unknown whether CTG18.1 expansions affect global methylation including TCF4 gene in CE or whether global CE methylation changes at advanced age. Using genome-wide DNA methylation array, we investigated methylation in CE from FECD patients with CTG18.1 expansions and studied the methylation in healthy CE at different ages. The most revealing DNA methylation findings were analyzed by gene expression and protein analysis. 3488 CpGs had significantly altered methylation pattern in FECD though no substantial changes were found in TCF4. The most hypermethylated site was in a predicted promoter of aquaporin 1 (AQP1) gene, and the most hypomethylated site was in a predicted promoter of coagulation factor V (F5 for gene, FV for protein). In FECD, AQP1 mRNA expression was variable, while F5 gene expression showed a ~ 23-fold increase. FV protein was present in both healthy and affected CE. Further gene expression analysis of coagulation factors interacting with FV revealed a ~ 34-fold increase of thrombomodulin (THBD). THBD protein was detected only in CE from FECD patients. Additionally, we observed an age-dependent hypomethylation in elderly healthy CE.Thus, tissue-specific genome-wide and gene-specific methylation changes associated with altered gene expression were discovered in FECD. TCF4 pathological methylation in FECD because of CTG18.1 expansion was ruled out.

Corneal transplantation in aniridia-related keratopathy with a two-year follow-up period, an uncommon disease with precarious course.

PURPOSE: The purpose of this study is to study the frequency, surgical transplantation technique and outcome in patients with aniridia-related keratopathy (ARK) with two-year follow-up period. METHODS: A retrospective registry-study including all ARK cases performed in Sweden and Denmark between 2001 and 2016 and registered in the Swedish Cornea Transplant Registry. RESULTS: A total of 36 eyes of 26 patients were subjected to corneal transplantation due to ARK during 2001 to 2016. Penetrating keratoplasty (PK) was the procedure of choice in 58.3% (n = 21) of the eyes, followed by a combination of PK and limbal stem cell transplantation in 13.9% (n = 5) and keratolimbal allograft in 13.9% (n = 5). Boston keratoprosthesis was used in 8.3% (n = 3), and anterior lamellar keratoplasty in 5.6% (n = 2). Thirteen of the procedures (36.1%) were retransplantations. Two years after surgery 26 cases were available to follow-up of which 16 of the grafts were functioning (61.5%). The median visual acuity showed a trend of improvement from hand motion to counting fingers. CONCLUSIONS: A majority of the ARK cases (61.5%) had a graft providing useful vision for the patient 2 years after corneal transplantation, but the visual gain was modest at best. Longer follow-up time is required to evaluate functional graft outcomes. Despite the introduction of limbal stem cell transplantation as a suitable treatment, PK was the most common surgical method in the present study.

Cataract surgery in patients with uveitis: Data from the Swedish National Cataract Register.

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.

Visual and satisfaction results with implantation of the trifocal Panoptix (R) intraocular lens in cataract surgery

Purpose: To assess visual results (including the Lapid-Kushlin defocus coefficient), and satisfaction, following the implantation of PanOptix® a trifocal intraocular lens.Methods: Observational, retrospective cohort study. 130 eyes of 65 subjects with bilateral implantation were included. Binocular uncorrected visual acuities [distance (Binocular UDVA), intermediate (Binocular UIVA) and near (Binocular UNVA)] were measured. Also, the manifest refraction, binocular defocus curve and binocular contrast sensitivity were determined. The Lapid-Kushlin defocus coefficient, a new single numerical parameter based on the area under the curve of the defocus curve, was calculated. The validated Spanish CATQUEST-9SF satisfaction survey was applied.Results: Postoperative visual acuity ranges were: binocular UDVA 0.18 to 0.0 LogMAR, binocular UIVA 0.30 to 0.0 LogMAR and Binocular UNVA 0.18 to 0.0 LogMAR. The levels of contrast sensitivity both in bright light conditions (with and without glare) and low light conditions with glare, remained within the limits of normality. Under scotopic conditions without glare values below normality were found at lower spatial frequencies. The binocular defocus curve showed a plateau without a clearly evident peak. The Lapid-Kushlin defocus coefficient was 0.199. Two patients (3.1%) needed glasses after the procedure for near and intermediate vision. No patient manifested great visual difficulties or was dissatisfied with the results.Conclusions: The trifocal platform showed very good results in this series of patients. 96.9% of the patients achieved independence of the glasses and expressed a high degree of satisfaction. The Lapid-Kushlin defocus coefficient was better than those calculated from literature, for other multifocal intraocular lenses. (AU)

Visual and satisfaction results with implantation of the trifocal Panoptix® intraocular lens in cataract surgery.

PURPOSE: To assess visual results (including the Lapid-Kushlin defocus coefficient), and satisfaction, following the implantation of PanOptix® a trifocal intraocular lens. METHODS: Observational, retrospective cohort study. 130 eyes of 65 subjects with bilateral implantation were included. Binocular uncorrected visual acuities [distance (Binocular UDVA), intermediate (Binocular UIVA) and near (Binocular UNVA)] were measured. Also, the manifest refraction, binocular defocus curve and binocular contrast sensitivity were determined. The Lapid-Kushlin defocus coefficient, a new single numerical parameter based on the area under the curve of the defocus curve, was calculated. The validated Spanish CATQUEST-9SF satisfaction survey was applied. RESULTS: Postoperative visual acuity ranges were: binocular UDVA 0.18 to 0.0 LogMAR, binocular UIVA 0.30 to 0.0 LogMAR and Binocular UNVA 0.18 to 0.0 LogMAR. The levels of contrast sensitivity both in bright light conditions (with and without glare) and low light conditions with glare, remained within the limits of normality. Under scotopic conditions without glare values below normality were found at lower spatial frequencies. The binocular defocus curve showed a plateau without a clearly evident peak. The Lapid-Kushlin defocus coefficient was 0.199. Two patients (3.1%) needed glasses after the procedure for near and intermediate vision. No patient manifested great visual difficulties or was dissatisfied with the results. CONCLUSIONS: The trifocal platform showed very good results in this series of patients. 96.9% of the patients achieved independence of the glasses and expressed a high degree of satisfaction. The Lapid-Kushlin defocus coefficient was better than those calculated from literature, for other multifocal intraocular lenses.

TCF4 trinucleotide repeat expansion in Swedish cases with Fuchs' endothelial corneal dystrophy.

PURPOSE: Fuchs' endothelial corneal dystrophy (FECD) has been considered a genetically heterogeneous disease but is increasingly associated with the transcription factor 4 (TCF4) gene. This study investigates the prevalence of the cytosine-thymine-guanine (CTG)n repeat expansion in TCF4 among FECD patients in northern Sweden coupled to the phenotype. METHODS: Blood samples were collected from 85 FECD cases at different stages. Short tandem repeat PCR and triplet repeat-primed PCR were applied in order to determine TCF4 (CTG)n genotype. RESULTS: A (CTG)n repeat expansion (n > 50) in TCF4 was identified in 76 of 85 FECD cases (89.4%) and in four of 102 controls (3.9%). The median (CTG)n repeat length was 81 (IQR 39.3) in mild FECD and 87 (IQR 13.0) in severe FECD (p = 0.01). A higher number of (CTG)n repeats in an expanded TCF4 allele increased the probability of severe FECD. Other ocular surgery was overrepresented in FECD cases without a (CTG)n repeat expansion (44.4%, n = 4) compared with 3.9% (n = 3) in FECD cases with an (CTG)n repeat expansion (p < 0.001). CONCLUSION: In northern Sweden, the FECD phenotype is associated with (CTG)n expansion in the TCF4 gene, with nearly 90% of patients being hetero- or homozygous for (CTG)n expansion over 50 repeats. Furthermore, the severity of FECD was associated with the repeat length in the TCF4 gene. Ocular surgery might act as an environmental factor explaining the clinical disease in FECD without a repeat expansion in TCF4.

Lower Fractions of TCF4 Transcripts Spanning over the CTG18.1 Trinucleotide Repeat in Human Corneal Endothelium.

Fuchs' endothelial corneal dystrophy (FECD) is a bilateral disease of the cornea caused by gradual loss of corneal endothelial cells. Late-onset FECD is strongly associated with the CTG18.1 trinucleotide repeat expansion in the Transcription Factor 4 gene (TCF4), which forms RNA nuclear foci in corneal endothelial cells. To date, 46 RefSeq transcripts of TCF4 are annotated by the National Center of Biotechnology information (NCBI), however the effect of the CTG18.1 expansion on expression of alternative TCF4 transcripts is not completely understood. To investigate this, we used droplet digital PCR for quantification of TCF4 transcripts spanning over the CTG18.1 and transcripts with transcription start sites immediately downstream of the CTG18.1. TCF4 expression was analysed in corneal endothelium and in whole blood of FECD patients with and without CTG18.1 expansion, in non-FECD controls without CTG18.1 expansion, and in five additional control tissues. Subtle changes in transcription levels in groups of TCF4 transcripts were detected. In corneal endothelium, we found a lower fraction of transcripts spanning over the CTG18.1 tract compared to all other tissues investigated.

Incidence of corneal transplantation after challenging cataract surgery in patients with and without corneal guttata.

PURPOSE: To study the risk for corneal transplantation after phacoemulsification with dense cataract or posterior capsule rupture (PCR) and the impact of corneal guttata. SETTING: Forty-nine Swedish cataract surgical units and 8 Swedish cornea transplantation units. DESIGN: Registry-based cohort study. METHODS: Patient data from the Swedish National Cataract Registry (2010 to 2012) were linked with data from the Swedish Cornea Transplant Registry (2010 to 2017). The outcome measures were risk for future corneal transplantation, visual acuity, and self-assessed visual function after phacoemulsification. Logistic and Poisson regression analyses with adjustment for confounder effects were used to investigate the association of the outcome measures with dense cataract, indicated by trypan blue capsular staining (TB) and PCR, separately and together. RESULTS: Altogether, data from 276 362 cataract patients were linked with data from 2091 patients with endothelial failure who underwent corneal transplantation.The risk for future corneal transplantation increased more than 3-fold with the presence of dense cataract or PCR, and a trend toward an ever-higher risk with the combination of TB and PCR together, but without any significant synergy of corneal guttata. Dense cataract, but not PCR, was significantly associated with an increased probability of inferior visual acuity after phacoemulsification. The impact on satisfaction was not statistically significant for any of the factors. CONCLUSIONS: Challenging cataract surgery increases the risk for future corneal transplantation equally in patients both with and without corneal guttata, despite a more vulnerable endothelium in the guttata group. This supports a strategy where PCR is limited and handled optimally and that cataract surgery is performed before the cataract turns critically dense.

Incidence of corneal transplantation after phacoemulsification in patients with corneal guttata: a registry-based cohort study.

PURPOSE: To investigate the risk for corneal transplantation after phacoemulsification related to corneal guttata. SETTING: Forty-nine Swedish cataract surgical units and 7 Swedish cornea transplantation units. DESIGN: Registry-based cohort study. METHODS: Patient data from the Swedish National Cataract Registry between 2010 and 2012 were linked with data from the Swedish Cornea Transplant Registry between 2010 and September 2017. Data from cataract patients were linked with data from patients who underwent corneal transplantation because of endothelial failure. Triple procedures and other surgical methods for cataract extraction other than phacoemulsification were excluded. If both eyes had surgery, 1 eye was randomly selected from the registry to obtain unrelated samples. The incidence was calculated per 10 000 person years, and Poisson regression analysis was used to investigate the risk for corneal transplantation because of endothelial failure after phacoemulsification. RESULTS: Altogether, data from 276 362 cataract patients were linked with data from 2091 patients who underwent corneal transplantation. The incidence rate of corneal transplantation after phacoemulsification among patients with corneal guttata was 88 per 10 000 person years (95% CI, 74.5-103.1). The annual incidence rate was highest within the first year and diminished thereafter. The incidence rate of corneal transplantation among patients without corneal guttata was 1.4 per 10 000 person years (95% CI, 1.2-1.6). Phacoemulsification in patients with corneal guttata was associated with corneal transplantation with an adjusted relative risk of 68.2 (95% CI, 54.0-86.2). CONCLUSIONS: The relative risk for corneal transplantation after phacoemulsification was 68.2 times higher for patients with corneal guttata than that for those without. Still, most of the patients with corneal guttata did not undergo corneal transplantation during the study period.

The impact of corneal guttata on the results of cataract surgery.

PURPOSE: To study the impact of corneal guttata on postoperative visual acuity and patients' self-assessed visual function after cataract surgery. SETTING: Patient data from 49 Swedish cataract surgery units. DESIGN: Retrospective cross-sectional register-based study. METHODS: Data from patients who had cataract surgery from 2010 to 2017 and completed the Catquest-9SF questionnaire were obtained from the Swedish National Cataract Register. Logistic proportional odds regression was used to model the impact of corneal guttata on the visual acuity and self-assessed visual function. Adjustments were made for age, sex, ocular comorbidities, days to follow-up, preoperative corrected distance visual acuity (CDVA) and preoperative Rasch person score. The main outcome measures were postoperative CDVA and Rasch person score calculated from the Catquest-9SF questionnaire. RESULTS: The study comprised data from 33 741 patients. Cataract surgery greatly improved CDVA and self-assessed visual function in patients both with and without corneal guttata. Still, corneal guttata was significantly associated with a poorer visual acuity and a worse self-assessed visual function after cataract surgery. The negative effect of corneal guttata on visual acuity was most prominent during the first 3 weeks postoperatively, but it persisted at least 3 months postoperatively. CONCLUSIONS: Patients with corneal guttata benefit substantially from cataract surgery but have an additional risk for inferior results compared with patients without corneal guttata. These findings could serve as valuable tools in clinical practice, in particular, when deciding to perform cataract surgery and how to inform the patient about surgical benefits and risks.