Genetic Risk Assessment of Degenerative Eye Disease (GRADE): study protocol of a prospective assessment of polygenic risk scores to predict diagnosis of glaucoma and age-related macular degeneration.

BACKGROUND: Glaucoma and age-related macular degeneration (AMD) account for a substantial portion of global blindness. Both conditions are highly heritable, with recognised monogenic and polygenic inheritance patterns. Current screening guidelines lack decisive recommendations. Polygenic risk scores (PRS) allow for cost-effective broad population risk stratification for these conditions. The predictive potential of PRS could facilitate earlier diagnosis and treatment, and prevent unnecessary vision loss. METHODS: The Genetic Risk Assessment of Degenerative Eye disease (GRADE) study is a prospective study designed to generate high-quality evidence about the feasibility of PRS to stratify individuals from the general population, enabling identification of those at highest risk of developing glaucoma or AMD. The targeted recruitment is 1000 individuals aged over 50 years, from which blood or saliva samples will be used for genotyping and an individual PRS for glaucoma and AMD will be derived. Individuals with PRS values in the bottom decile (n = 100), top decile (n = 100) and middle 80% (n = 100) for both glaucoma and AMD will undergo a detailed eye examination for glaucoma and/or AMD. DISCUSSION: The primary objective will be to compare the prevalence of glaucoma and AMD cases between low, intermediate, and high PRS risk groups. We expect to find a higher prevalence of both diseases in the high PRS risk group, as compared to the middle and low risk groups. This prospective study will assess the clinical validity of a PRS for glaucoma and AMD in the general Australian population. Positive findings will support the implementation of PRS into clinical practice.

High Polygenic Risk Is Associated with Earlier Initiation and Escalation of Treatment in Early Primary Open-Angle Glaucoma.

PURPOSE: To assess the association between a glaucoma polygenic risk score (PRS) and treatment outcomes in primary open-angle glaucoma. DESIGN: Prospective, observational cohort study. PARTICIPANTS: Participants from the Progression Risk of Glaucoma: Relevant SNPs with Significant Association Study were divided into a cohort with suspect glaucoma who were treatment naive at enrollment and one with early manifest and suspect glaucoma receiving treatment at enrollment. METHODS: A per-allele weighted glaucoma PRS was calculated for 1107 participants. Multivariable mixed-effects Cox proportional regression analysis assessed the association between PRS and time to commencement of intraocular pressure (IOP)-lowering therapy in 416 patients with suspect glaucoma who were treatment naive at study enrollment. Secondary analysis evaluated the association between PRS and escalation of IOP-lowering therapy among 691 patients with suspect and early manifest glaucoma who were receiving IOP-lowering therapy at enrollment. MAIN OUTCOME MEASURES: Commencement or escalation of IOP-lowering therapy. RESULTS: A higher PRS was associated with a greater risk of commencing IOP-lowering therapy within 5 years (hazard ratio [HR], 1.45 per 1 standard deviation [/SD]; 95% confidence interval [CI], 1.27-1.62; P < 0.001). Participants in the upper population-based quintile showed a 3.3 times greater risk of commencing therapy by 5 years than those in the lowest quintile (HR, 3.30; 95% CI, 1.63-6,70; P < 0.001) and a 5.4 times greater risk of commencing IOP-lowering therapy by 2 years than the those in the lowest quintile (HR, 5.45; 95% CI, 2.08-14.25; P < 0.001). A higher PRS was associated with a greater risk of treatment escalation among patients receiving treatment at enrollment (HR, 1.19/SD; 95% CI, 1.09-1.31; P < 0.001). In combined analysis of all participants, participants in the top population-based quintile were at 2.3 times greater risk of requiring initiation or escalation of IOP-lowering therapy than those in the lowest quintile (HR, 2.33; 95% CI, 1.75-3.01; P < 0.001). CONCLUSIONS: This study demonstrated novel associations between glaucoma polygenic risk and risk of commencement or escalation of IOP-lowering therapy, building on previous work highlighting the potential clinical usefulness of genetic risk stratification in glaucoma. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.

Physical Activity Is Associated With Macular Thickness: A Multi-Cohort Observational Study.

Purpose: To assess the association between physical activity and spectral-domain optical coherence tomography (SD-OCT)-measured rates of macular thinning in an adult population with primary open-angle glaucoma. Methods: The correlation between accelerometer-measured physical activity and rates of macular ganglion cell-inner plexiform layer (GCIPL) thinning was measured in 735 eyes from 388 participants of the Progression Risk of Glaucoma: RElevant SNPs with Significant Association (PROGRESSA) study. The association between accelerometer-measured physical activity and cross-sectional SD-OCT macular thickness was then assessed in 8862 eyes from 6152 participants available for analysis in the UK Biobank who had SD-OCT, ophthalmic, comorbidity, and demographic data. Results: Greater physical activity was associated with slower rates of macular GCIPL thinning in the PROGRESSA study (beta = 0.07 µm/y/SD; 95% confidence interval [CI], 0.03-0.13; P = 0.003) after adjustment for ophthalmic, demographic and systemic predictors of macular thinning. This association persisted in subanalyses of participants characterized as glaucoma suspects (beta = 0.09 µm/y/SD; 95% CI, 0.03-0.15; P = 0.005). Participants in the upper tertile (greater than 10,524 steps/d) exhibited a 0.22-µm/y slower rate of macular GCIPL thinning than participants in the lower tertile (fewer than 6925 steps/d): -0.40 ± 0.46 µm/y versus -0.62 ± 0.55 µm/y (P = 0.003). Both time spent doing moderate/vigorous activity and mean daily active calories were positively correlated with rate of macular GCIPL thinning (moderate/vigorous activity: beta = 0.06 µm/y/SD; 95% CI, 0.01-0.105; P = 0.018; active calories: beta = 0.06 µm/y/SD; 95% CI, 0.006-0.114; P = 0.032). Analysis among 8862 eyes from the UK Biobank revealed a positive association between physical activity and cross-sectional total macular thickness (beta = 0.8 µm/SD; 95% CI, 0.47-1.14; P < 0.001). Conclusions: These results highlight the potential neuroprotective benefits of exercise on the human retina.

High Polygenic Risk Is Associated with Earlier Trabeculectomy in Patients with Primary Open-Angle Glaucoma.

PURPOSE: To evaluate the association between a polygenic risk score (PRS) for primary open-angle glaucoma (POAG) and the age at the first trabeculectomy and the need for bilateral trabeculectomy. DESIGN: Retrospective observational cohort study. PARTICIPANTS: Nine hundred and three genotyped participants with POAG from the Australian and New Zealand Registry of Advanced Glaucoma. METHODS: The ocular surgical history of these participants was reviewed and the following parameters were recorded: age at diagnosis, age at trabeculectomy, and lateraly of trabeculectomy. Multivariate linear regression analyses correlated glaucoma PRSs with age at trabeculectomy, and laterality of trabeculectomy. For descriptive purposes, the participants were stratified into the top decile, intermediate group (10th-89th percentile), and bottom decile. MAIN OUTCOME MEASURES: Age at trabeculectomy, and laterality of trabeculectomy. RESULTS: Higher PRS was associated with younger age at the first trabeculectomy (ß, -1.94 years/standard deviation; 95% confidence interval [CI], - 0.41 to -3.47; P = 0.014). Participants in the top decile underwent their first trabeculectomy approximately 7 years earlier than participants in the lowest decile (mean difference, -7.04 years; 95% CI, 2.82-11.26). Participants in the top decile were 1.41-fold more likely to require bilateral trabeculectomy than participants in the bottom decile (odds ratio, 1.41; 95% CI, 1.06-1.91; P = 0.021). CONCLUSIONS: This report identified clinically relevant correlations between glaucoma PRS and the need for surgical intervention in patients with glaucoma. Further work is required to investigate the association between PRS and other clinical end points such as treatment initiation.

Genetic Risk of Cardiovascular Disease Is Associated with Macular Ganglion Cell-Inner Plexiform Layer Thinning in an Early Glaucoma Cohort.

Purpose: To evaluate the association between genetic risk for cardiovascular disease and retinal thinning in early glaucoma. Design: Prospective, observational genetic association study. Participants: Multicohort study combining a cohort of patients with suspect and early manifest primary open-angle glaucoma (POAG), a cohort of patients with perimetric POAG, and an external normative control cohort. Methods: A cardiovascular disease genetic risk score was calculated for 828 participants from the Progression Risk of Glaucoma: Relevant SNPs [single nucleotide polymorphisms] with Significant Association (PROGRESSA) study. Participants were characterized as showing either predominantly macular ganglion cell-inner plexiform layer (GCIPL), predominantly peripapillary retinal nerve fiber layer (pRNFL) or equivalent macular GCIPL and pRNFL spectral-domain OCT thinning. The cardiovascular disease genetic risk scores for these groups were compared to an internal reference group of stable suspected glaucoma and of an external normative population. Replication was undertaken by comparing the phenotypes of participants from the Australia New Zealand Registry of Advanced Glaucoma (ANZRAG) with the normative control group. Main Outcome Measures: Spectral-domain OCT and Humphrey Visual Field (HVF) change. Results: After accounting for age, sex, and intraocular pressure (IOP), participants with predominantly macular GCIPL thinning showed a higher cardiovascular disease genetic risk score than reference participants (odds ratio [OR], 1.76/standard deviation [SD]; 95% confidence interval [CI], 1.18-2.62; P = 0.005) and than normative participants (OR, 1.32/SD; 95% CI, 1.12-1.54; P = 0.002). This finding was replicated by comparing ANZRAG participants with predominantly macular GCIPL change with the normative population (OR, 1.39/SD; 95% CI, 1.05-1.83; P = 0.022). Review of HVF data identified that participants with paracentral visual field defects also demonstrated a higher cardiovascular disease genetic risk score than reference participants (OR, 1.85/SD; 95% CI, 1.16-2.97; P = 0.010). Participants with predominantly macular GCIPL thinning exhibited a higher vertical cup-to-disc ratio genetic risk score (OR, 1.48/SD; 95% CI, 1.24-1.76; P < 0.001), but an IOP genetic risk score (OR, 1.12/SD; 95% CI, 0.95-1.33; P = 0.179) comparable with that of the normative population. Conclusions: This study highlighted the relationship between cardiovascular disease and retinal thinning in suspect and manifest glaucoma cases.

The phenotypic spectrum of ADAMTSL4-associated ectopia lentis: Additional cases, complications, and review of literature.

Purpose: ADAMTSL4-associated ectopia lentis is a rare autosomal recessive condition that is primarily associated with crystalline lens displacement. However, the prevalence of other ocular and systemic manifestations of this condition is poorly understood. In this study, we summarize the ocular and systemic phenotypic spectrum of this condition. Methods: A cross-sectional case study series of four individuals with biallelic pathogenic or likely pathogenic ADAMTSL4 variants was performed alongside a literature review of individuals with ADAMTSL4-associated ectopia lentis on September 29, 2021. Ocular and systemic findings, complications, and genetic findings of all four individuals were collected and summarized. Results: The phenotypic spectrum across 91 individuals sourced from literature and four individuals from this case study series was highly variable. The main ocular phenotypes included ectopia lentis (95/95, 100%), ectopia lentis et pupillae (18/95, 19%), iris transillumination (13/95, 14%), iridodonesis (12/95, 13%), persistent pupillary membrane (12/95, 13%), and early-onset cataract or lens opacities (12/95, 13%). Anterior segment features other than ectopia lentis appeared to be exclusively associated with biallelic loss of function variants (p<0.001). Pupillary block glaucoma had a prevalence of 1%. Post-lensectomy complications included retinal detachment (6/41, 15%), elevated intraocular pressure (4/41, 10%), and aphakic glaucoma (1/41, 2%). Most individuals were not reported to have had systemic features (69/95, 73%). Conclusions: The clinical phenotype of ADAMTSL4-associated ectopia lentis was summarized and expanded. Clinicians should be aware of the varied ocular phenotype and the risks of retinal detachment, ocular hypertension, and glaucoma in the diagnosis and management of this condition.

Attitudes Toward Glaucoma Genetic Risk Assessment in Unaffected Individuals.

Purpose: Integrating polygenic risk scores (PRS) into healthcare has the potential to stratify an individual's risk of glaucoma across a broad population. Glaucoma is the most common cause of irreversible blindness worldwide, therefore effective screening for glaucoma endorsed by the population is highly important. This study assessed the attitude of unaffected individuals toward PRS testing for glaucoma, and sought to identify factors associated with interest in testing. Methods: We surveyed 418 unaffected individuals including 193 with a first-degree relative with glaucoma, 117 who had a recent eye examination, and 108 general members of the community. Results: Overall, 71.3% of the individuals indicated an interest in taking a polygenic risk test for glaucoma. Interest was more likely in those who believed glaucoma to be a severe medical condition (odds ratio [OR] = 14.58, 95% confidence interval [CI] = 1.15-185.50, P = 0.039), those concerned about developing glaucoma (OR = 4.37, 95% CI = 2.32-8.25, P < 0.001), those with an intention to take appropriate measures regarding eye health (OR = 2.39, 95% CI = 1.16-4.95, P = 0.019), and those preferring to know if considered to be at-risk or not (OR = 4.52, 95% CI = 2.32-8.83, P < 0.001). Conclusions: Our results show strong interest in genetic risk assessment for glaucoma among unaffected individuals in Australia. Translational Relevance: These findings represent a valuable assessment of interest in glaucoma polygenic risk testing among potential target populations, which will be integral to the implementation and uptake of novel PRS-based tests into clinical practice.

Attitudes Towards Polygenic Risk Testing in Individuals with Glaucoma.

PURPOSE: Glaucoma is the leading cause of irreversible blindness worldwide; however, vision loss resulting from glaucoma generally can be prevented through early identification and timely implementation of treatment. Recently, polygenic risk scores (PRSs) have shown promise in stratifying individual risk and prognostication for primary open-angle glaucoma (POAG) to reduce disease burden. Integrating PRS testing into clinical practice is becoming increasingly realistic; however, little is known about the attitudes of patients toward such testing. DESIGN: Cross-sectional, questionnaire-based study. PARTICIPANTS: Among the participants in the Australian and New Zealand Registry of Advanced Glaucoma, 2369 were invited to participate who fit the inclusion criteria of adults with a diagnosis of POAG who had not received genetic results that explain their condition, were not known to be deceased, resided in Australia, and had agreed to receive correspondence. METHODS: One thousand one hundred sixty-nine individuals (response rate, 49%) with POAG completed the survey evaluating their attitudes towards polygenic risk testing for glaucoma. MAIN OUTCOME MEASURES: Sociodemographic, health, perception, and emotional factors were examined to assess associations with interest in PRS testing. Interest in PRS testing was evaluated through assessing likelihood to take the test to predict personal risk of disease and disease severity, and whether the individual would recommend the test to family members or others. RESULTS: Our results show strong interest in the test, with 69.4% of individuals (798 of 1150) indicating a keenness in testing before diagnosis, had it been available. In particular, interest was seen in those from an urban area (odds ratio [OR], 1.70; 95% confidence interval [CI], 1.15-2.49; P = 0.007), those who perceived their risk of developing glaucoma as higher (OR, 2.05; 95% CI, 1.28-3.29; P = 0.003), and those who were worried about developing glaucoma (OR, 2.07; 95% CI, 1.27-3.37; P = 0.004). People who were interested in testing were more likely to change their eye health-seeking intentions and to recommend testing to family members and others, as well as to undergo testing for prognostication. CONCLUSIONS: These findings will help to facilitate the clinical implementation of PRS testing for glaucoma to reduce irreversible vision loss.