New insights into the genetics of primary open-angle glaucoma based on meta-analyses of intraocular pressure and optic disc characteristics

Primary open-angle glaucoma (POAG), the most common optic neuropathy, is a highly heritable disease (h2 = 0.42 ± 0.09). Siblings of POAG cases have a ten-fold increase risk of developing the disease. Intraocular pressure (IOP) and optic nerve head characteristics are used clinically to predict POAG risk. We conducted a genome-wide association meta-analysis of IOP and optic disc parameters and validated our findings in multiple sets of POAG cases and controls. Using imputation to the 1000 genomes (1000G) reference set, we identified 9 new genomic regions associated with vertical cup disc ratio (VCDR) and 1 new region associated with IOP. Additionally, we found 5 novel loci for optic nerve cup area and 6 for disc area. Previously it was assumed that genetic variation influenced POAG either through IOP or via changes to the optic nerve head; here we present evidence that some genomic regions affect both IOP and the disc parameters. We characterized the effect of the novel loci through pathway analysis and found that pathways involved are not entirely distinct as assumed. Further, we identified a novel association between CDKN1A and POAG. Using a zebrafish model we show that six6b (associated with POAG and optic nerve head variation) alters the expression of cdkn1a. In summary, we have identified several novel genes influencing the major clinical risk predictors of POAG and showed that genetic variation in CDKN1A is important in POAG ris

Prevalence and causes of blindness in subjects of 55 years and older:The Rotterdam study

Purpose. To study the prevalence and causes of blindness and low vision in a middle-aged and elderly population of the Netherlands. Methods. In a single center prospective follow-up study of 7983 subjects in Rotterdam, 6178 subjects of 55 years and older underwent a complete ophthalmological examination. The grade of visual impairment was classified according to WHO-standards: subjects with best-corrected visual acuity &lt; 0.05 in the better eye were defined as blind, subjects with visual acuity &lt; 0.3 in the better eye were defined as visually impaired. Results. We identified 32 subjects who were bilaterally blind and 98 subjects who were bilaterally visually impaired. Overall prevalence of blindness was 0.5%, ranging from 0.1% in subjects under 60 to 3.9% in subjects of 85 and older. Prevalence of visual impairment was 1.4%, ranging from 0.2% to 12.0%. Major causes of blindness were age-related macular degeneration (55%), myopic degeneration (7%), glaucoma (7%), cataract (7%), and a combination of the above pathology (17%). Conclusions. Age-related macular degeneration is by far the major cause of severe visual impairment in this predominantly white population of 55 years and older.</p

Prevalence and causes of blindness in subjects of 55 years and older:The Rotterdam study

Purpose. To study the prevalence and causes of blindness and low vision in a middle-aged and elderly population of the Netherlands. Methods. In a single center prospective follow-up study of 7983 subjects in Rotterdam, 6178 subjects of 55 years and older underwent a complete ophthalmological examination. The grade of visual impairment was classified according to WHO-standards: subjects with best-corrected visual acuity &lt; 0.05 in the better eye were defined as blind, subjects with visual acuity &lt; 0.3 in the better eye were defined as visually impaired. Results. We identified 32 subjects who were bilaterally blind and 98 subjects who were bilaterally visually impaired. Overall prevalence of blindness was 0.5%, ranging from 0.1% in subjects under 60 to 3.9% in subjects of 85 and older. Prevalence of visual impairment was 1.4%, ranging from 0.2% to 12.0%. Major causes of blindness were age-related macular degeneration (55%), myopic degeneration (7%), glaucoma (7%), cataract (7%), and a combination of the above pathology (17%). Conclusions. Age-related macular degeneration is by far the major cause of severe visual impairment in this predominantly white population of 55 years and older.</p

Efficacy and Safety of Micropulse Transscleral Cyclophotocoagulation

Background: Early studies have shown that micropulse transscleral cyclophotocoagulation (MP-TSCPC) might be an effective and safe treatment option for lowering intraocular pressure (IOP). These studies were, however, somewhat limited, in particular by their retrospective nature and the length of follow-up. Therefore, we assessed the efficacy and safety of this novel treatment in a large cohort for up to 4 years. Methods: We performed a prospective cohort study, including all patients who were treated with MP-TSCPC since November 2017. The primary outcome was a reduction of IOP and the number of IOP-lowering medications. Results: The mean ± standard deviation baseline IOP and number of IOP-lowering medications were 26.6 ± 10.8 mmHg and 3.3 ± 1.3. IOP was reduced by 8.2 ± 7.9 (31.8% reduction), 6.9 ± 8.7 (28.1% reduction), and 7.1 ± 8.4 (30.2% reduction) mmHg after 6, 12, and 24 months, respectively (p < 0.001). The mean postoperative number of IOP-lowering medications was significantly reduced after 6 months by 0.6 ± 1.5 (p = 0.002) but was not significantly different after 12 or 24 months. Oral acetazolamide was significantly reduced from 28 (29%) eyes before treatment, to 9 (9%) at the last follow-up visit (p < 0.001). No major complications were observed after treatment. Conclusions: MP-TSCPC is a safe and effective treatment option for lowering IOP, but only reduced IOP-lowering medications in the first 6 months after treatment. However, MP-TSCPC is especially effective in getting patients off oral IOP-lowering drugs

Efficacy of the PRESERFLO MicroShunt and a Meta-Analysis of the Literature

Background: Recent studies on the PRESERFLO MicroShunt suggest that it may be effective in lowering intraocular pressure (IOP); however, the number of studies on this device remains limited. Therefore, we assessed the efficacy of the PRESERFLO MicroShunt in patients with glaucoma and performed a meta-analysis of published results. Methods: Prospective study including all patients that underwent PRESERFLO MicroShunt surgery from 2018 onwards. Sub-analyses were performed for cataract-combined procedures. To compare our results, we performed a systematic review and meta-analysis. IOP, IOP-lowering medication and surgical complications reported in the retrieved studies were assessed. Results: A total of 72 eyes underwent PRESERFLO-implant surgery (59 as standalone procedure and 13 as cataract-combined procedure). No significant differences were found in IOP and IOP-lowering medication between both groups. The mean ± standard deviation IOP and IOP-lowering medications of both groups taken together declined from 21.72 ± 8.35 to 15.92 ± 8.54 mmHg (p < 0.001, 26.7% reduction) and 3.40 to 0.93 (p < 0.001, 72.6% reduction) at 1 year follow-up, respectively. Secondary surgeries were required in 19.4% of eyes, the majority (71.4%) within 6 months. The meta-analysis including 14 studies (totaling 1213 PRESERFLO MicroShunt surgeries) from the systematic review showed a mean preoperative IOP and IOP-lowering medication of 22.28 ± 5.38 and 2.97 ± 1.07, respectively. The three-years postoperative pooled mean was (weighted mean difference, 95% CI) 11.07 (10.27 [8.23–12.32], p < 0.001) mmHg and 0.91 (1.77 [1.26–2.28], p < 0.001) for IOP and IOP-lowering medication, respectively. The most common reported complication was hypotony (2–39%). Conclusion: The PRESERFLO MicroShunt is effective and safe in lowering IOP and the number of IOP-lowering medications

Clinical implications of old and new genes for open-angle glaucoma

Objective: Genome-wide association studies have revealed new insights into the genetic determinants of open-angle glaucoma (OAG). This study was performed to determine to what extent variants within established genes (MYOC, OPTN, and WDR36) and newly identified common genetic variants (ATOH7, CDKN2B, and SIX1) contribute to the risk of OAG.Design: Population-based setting, family-based setting, and a case-control study.Participants: The Rotterdam Study I cohort (N = 5312; mean age±standard deviation [SD], 68.0±8.4 years). Findings were replicated in the Genetic Research in Isolated Populations combined with the Erasmus Rucphen Family study (N = 1750; mean age±SD, 48.3±15.2 years), and a cohort from Southampton (N = 702; mean age±SD, 72.5±10.7 years).Methods: After identifying common variants associated with OAG within the established genes, the risk of OAG was analyzed using logistic regression. Discriminative accuracy was assessed by comparing the area under the receiver operator characteristic curve (AUC) for models, including the number of risk alleles, intraocular pressure, age, and gender, with the AUC for the same model but without the risk alleles.Main Outcome Measures: Odds ratios and AUCs of individual and combined risk alleles.Results: No consistent significant associations for the established genes (MYOC, OPTN, and WDR36) with OAG were found. However, when comparing the load of risk variants between cases and controls, 2 of 3 studies showed a significant increased risk of OAG for participants carrying more risk alleles of the 3 established genes. When combining all 6 genes, participants carrying a high number of risk alleles (highest tertile) had a 2.29-fold to 3.19-fold increase in risk of OAG compared with those carrying only a few risk alleles. The addition of the newly identified genes to IOP, age, and gender resulted in a higher AUC compared with the AUC without the newly identified genes (P = 0.027).Conclusions: A significant contribution to the risk of OAG was found for the new common variants identified by recent genome-wide association studies, but not for variants within the established genes. Participants carrying a high number of risk alleles had an approximately 3-fold increase in the risk of OAG compared with those with a low number of risk alleles.<br/

Common genetic variants associated with open-angle glaucoma

Open-angle glaucoma (glaucoma) is a major eye disorder characterized by optic disc pathology. Recent genome-wide association studies identified new loci associated with clinically relevant optic disc parameters, such as the optic disc area and vertical cup-disc ratio (VCDR). We examined to what extent these loci are involved in glaucoma. The loci studied include ATOH7, CDC7/TGFBR3 and SALL1 for optic disc area, and CDKN2B, SIX1, SCYL1/LTBP3, CHEK2, ATOH7 and DCLK1 for VCDR. We performed a meta-analysis using data from six independent studies including: the Rotterdam Study (n= 5736), Genetic Research in Isolated Populations combined with Erasmus Rucphen Family study (n= 1750), Amsterdam Glaucoma Study (n= 296) and cohorts from Erlangen and Tübingen (n= 1363), Southampton (n= 702) and deCODE (n= 36 151) resulting in a total of 3161 glaucoma cases and 42 837 controls. Of the eight loci, we found significant evidence (P= 1.41 × 10(-8)) for the association of CDKN2B with glaucoma [odds ratio (OR) for those homozygous for the risk allele: 0.76; 95% confidence interval (CI): 0.70-0.84], for the role of ATOH7 (OR: 1.28; 95% CI: 1.12-1.47) and for SIX1 (OR: 1.20; 95% CI: 1.10-1.31) when adjusting for the number of tested loci. Furthermore, there was a borderline significant association of CDC7/TGFBR3 and SALL1 (both P= 0.04) with glaucoma. In conclusion, we found consistent evidence for three common variants (CDKN2B, ATOH7 and SIX1) significantly associated with glaucoma. These findings may shed new light on the pathophysiological protein pathways leading to glaucoma, and point to pathways involved in the growth and development of the optic nerve

Genome-wide analysis of multi-ancestry cohorts identifies new loci influencing intraocular pressure and susceptibility to glaucoma.

To access publisher's full text version of this article click on the hyperlink at the bottom of the pageElevated intraocular pressure (IOP) is an important risk factor in developing glaucoma, and variability in IOP might herald glaucomatous development or progression. We report the results of a genome-wide association study meta-analysis of 18 population cohorts from the International Glaucoma Genetics Consortium (IGGC), comprising 35,296 multi-ancestry participants for IOP. We confirm genetic association of known loci for IOP and primary open-angle glaucoma (POAG) and identify four new IOP-associated loci located on chromosome 3q25.31 within the FNDC3B gene (P = 4.19 × 10(-8) for rs6445055), two on chromosome 9 (P = 2.80 × 10(-11) for rs2472493 near ABCA1 and P = 6.39 × 10(-11) for rs8176693 within ABO) and one on chromosome 11p11.2 (best P = 1.04 × 10(-11) for rs747782). Separate meta-analyses of 4 independent POAG cohorts, totaling 4,284 cases and 95,560 controls, showed that 3 of these loci for IOP were also associated with POAG.K08 EY022943/EY/NEI NIH HHS/United State