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.

No Strong Association between the Apolipoprotein E E4 Allele and Glaucoma: A Multicohort Study.

Purpose: To elucidate a potential association between the apolipoprotein E (APOE) E4 allele and glaucoma prevalence in large cohorts. Design: A cross-sectional analysis of baseline and prospectively collected cohort data. Participants: UK Biobank (UKBB) participants of genetically determined European ancestry (n = 438 711). Replication analyses were performed using clinical and genotyping data collected from European participants recruited to the Canadian Longitudinal Study of Aging (CLSA; n = 18 199), the Australian and New Zealand Registry of Advanced Glaucoma (ANZRAG; n = 1970), and the Blue Mountains Eye Study (BMES; n = 2440). Methods: Apolipoprotein E alleles and genotypes were determined, and their distributions were compared on the basis of glaucoma status. Similar analyses were performed using positive control outcomes associated with the APOE E4 allele (death, dementia, age-related macular degeneration) and negative control outcomes not associated with the APOE E4 allele (cataract, diabetic eye disease). Outcome phenotypes were also correlated with Alzheimer's dementia (AD), a clinical outcome highly associated with the APOE E4 allele. Main Outcome Measures: Results of APOE E4 genotype-phenotype comparisons were reported as odds ratios (ORs) with 95% confidence intervals (CIs). Replication analyses investigated APOE E4 associations in 2 replication cohorts (CLSA and ANZRAG/BMES). Results: The APOE E4 allele was inversely associated with glaucoma (OR, 0.96; 95% CI, 0.93-0.99; P = 0.016) and both negative controls (cataract: OR, 0.98; 95% CI, 0.96-0.99; P = 0.015; diabetic eye disease: OR, 0.92; 95% CI, 0.87-0.97; P = 0.003) in the UKBB cohort. A paradoxical positive association was observed between AD and both glaucoma (OR, 1.30; 95% CI, 1.08-1.54; P < 0.01) and cataract (OR, 1.15; 1.04-1.28; P = 0.018). No association between the APOE E4 allele and glaucoma was observed in either replication cohort (CLSA: OR, 1.03; 95% CI, 0.89-1.19; P = 0.66; ANZRAG/BMES: OR, 0.97; 95% CI, 0.84-1.12; P = 0.65). Conclusions: A small negative association observed between APOE E4 and glaucoma within the UKBB was not evident in either replication cohort and may represent an artifact of glaucoma underdiagnosis in APOE E4 carriers. Financial Disclosures: The author(s) have no proprietary or commercial interest in any materials discussed in this article.

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.

Optimising fundoscopy practices across the medical spectrum: A focus group study.

INTRODUCTION: Fundoscopy can be of great clinical value, yet remains underutilised. Educational attempts to improve fundoscopy utilisation have had limited success. We aimed to explore the barriers and facilitators underlying the uptake of clinical direct ophthalmoscopy across a spectrum of medical specialties and training levels. METHODS: Ten focus groups were conducted with medical students (n = 42), emergency department doctors (n = 24), basic physician trainees (n = 7), hospital physicians (n = 6) and general practitioners (n = 7). Independent thematic analysis of transcripts was conducted by three investigators. A consensus thematic framework was developed, and transcripts were reanalysed using this framework. RESULTS: Thematic analysis identified seven main themes: (1) technical barriers to performing fundoscopy examinations; (2) clinical culture and expectations regarding fundoscopy; (3) the influence of fundoscopy on clinical management; (4) motivation to perform the examination; (5) novel technology including smartphone fundoscopy, and the value of a digital fundus image; (6) training requirements, and; (7) use of limited resources. CONCLUSION: Our results build a more nuanced picture of the factors which determine fundoscopy utilisation. As current barriers limit practice by clinicians and medical students, expertise and confidence performing and interpreting fundoscopy are lost. This shifts the balance of perceived clinical utility to futility in changing patient management, and reinforces a cycle of reducing fundoscopy utilisation. We identified important cultural barriers such as accepted incompetence, and misperceptions of senior discouragement. Emerging technologies reduce the technical barriers to fundoscopy. Therefore education should: focus on detecting pathology from digital images; clarify the role of fundoscopy in patient management, and; be targeted at key career progression points.

Association Between Body Mass Index and Primary Open Angle Glaucoma in Three Cohorts.

PURPOSE: To evaluate the relationship between body mass index (BMI) and glaucoma progression. DESIGN: Multicohort observational study. METHODS: This study combined a retrospective longitudinal analysis of suspect and early manifest primary open angle glaucoma cases from the Progression Risk of Glaucoma: RElevant SNPs with Significant Association (PROGRESSA) study with 2 replication cohorts from the UK Biobank and the Canadian Longitudinal Study of Ageing (CLSA). In the PROGRESSA study, multivariate analysis correlated BMI with longitudinal visual field progression in 471 participants. The BMI was then associated with glaucoma diagnosis and cross-sectional vertical cup-disc ratio (VCDR) measurements in the UK Biobank, and finally prospectively associated with longitudinal change in VCDR in the CLSA study. RESULTS: In the PROGRESSA study, a lower BMI conferred a faster rate of visual field progression (mean duration of monitoring (5.28 ± 1.80 years (10.6 ± 3.59 visits) (ß 0.04 dB/year/SD95% CI [0.005, 0.069]; P = .013). In the UK Biobank, a 1 standard deviation lower BMI was associated with a worse cross-sectional VCDR (ß -0.048/SD 95% CI [-0.056, 0.96]; P < .001) and a 10% greater likelihood of glaucoma diagnosis, as per specialist grading of retinal fundus imaging (OR 0.90 95% CI [0.84, 0.98]; P = .011). Similarly, a lower BMI was associated with a greater risk of glaucoma diagnosis as per International Classification of Disease data (OR 0.94/SD; 95% CI [0.91, 0.98]; P = .002). Body mass index was also positively correlated with intraocular pressure (ß 0.11/SD; 95% CI [0.06, 0.15]; P < .001). Finally, a lower BMI was then associated with greater VCDR change in the CLSA (ß -0.007/SD; 95% CI [-0.01, -0.001]; P = .023). CONCLUSIONS: Body mass index correlated with longitudinal and cross-sectional glaucomatous outcomes. This supports previous work illustrating a correlation between BMI and glaucoma.

Association of High Polygenic Risk With Visual Field Worsening Despite Treatment in Early Primary Open-Angle Glaucoma.

Importance: Irreversible vision loss from primary open-angle glaucoma (POAG) can be prevented through timely diagnosis and treatment, although definitive diagnosis can be difficult in early-stage disease. As a consequence, large numbers of individuals with suspected glaucoma require regular monitoring, even though many of these may never develop disease and other high-risk individuals with suspected glaucoma may have delayed or inadequate treatment. POAG is one of the most heritable common diseases, and this provides an opportunity to use genetic instruments in risk-stratified screening, diagnosis, and treatment of early glaucoma. Objective: To assess the association of glaucoma polygenic risk with glaucoma progression in early-stage disease. Design, Setting, and Participants: This cohort study used clinical and genetic data obtained from a longitudinal cohort study, Progression Risk of Glaucoma: Relevant SNPs With Significant Association (PROGRESSA). Participants of European ancestry with characteristic optic nerve head changes suggestive of glaucoma were included. Data were collected between February 2012 and June 2020. Analysis took place between July 2020 and April 2022. Main Outcomes and Measures: The association of a glaucoma polygenic risk score (PRS) (2673 uncorrelated variants) with rate of peripapillary retinal nerve fiber layer thinning on optical coherence tomography and progression of visual field loss on 24-2 Humphrey visual fields. Results: A total of 1777 eyes from 896 individuals had sufficient data for structural progression analyses and 1563 eyes from 808 individuals for functional progression analyses. The mean (SD) age was 62.1 (9.9) years, 488 (44%) were male, and 1087 of 1103 individuals (98.5%) had European ancestry. An ancestrally matched normative population cohort (n = 17 642) was used for PRS reference. Individuals in the top 5% PRS risk group were at a higher risk of visual field progression compared with the remaining 95% after 5 years (hazard ratio, 1.5; 95% CI, 1.13-1.97; P = .005). Conversely, those in the bottom 20% PRS risk group were at a lower risk of visual field progression compared with an intermediate risk group over 3 years (hazard ratio, 0.52; 95% CI, 0.28-0.96; P = .04). Conclusions and Relevance: In this study, high polygenic risk was associated with more rapid structural and functional progression in early POAG, despite more intensive treatment. A PRS may serve as a valuable adjunct to identify individuals who stand to benefit the most from more frequent surveillance and earlier or more intensive treatment.

The APOE E4 Allele Is Associated with Faster Rates of Neuroretinal Thinning in a Prospective Cohort Study of Suspect and Early Glaucoma.

Purpose: To investigate the association between the apolipoprotein E (APOE) E4 dementia-risk allele and prospective longitudinal retinal thinning in a cohort study of suspect and early manifest glaucoma. Design: Retrospective analysis of prospective cohort data. Participants: This study included all available eyes from participants recruited to the Progression Risk of Glaucoma: Relevant SNPs [single nucleotide polymorphisms] with Significant Association (PROGRESSA) study with genotyping data from which APOE genotypes could be determined. Methods: Apolipoprotein E alleles and genotypes were determined in PROGRESSA, and their distributions were compared with an age-matched and ancestrally matched normative cohort, the Blue Mountains Eye Study. Structural parameters of neuroretinal atrophy measured using spectral-domain OCT were compared within the PROGRESSA cohort on the basis of APOE E4 allele status. Main Outcome Measures: Longitudinal rates of thinning in the macular ganglion cell-inner plexiform layer (mGCIPL) complex and the peripapillary retinal nerve fiber layer (pRNFL). Results: Rates of mGCIPL complex thinning were faster in participants harboring ≥1 copies of the APOE E4 allele (ß = -0.13 µm/year; P ≤0.001). This finding was strongest in eyes affected by normal-tension glaucoma (NTG; ß = -0.20 µm/year; P = 0.003). Apolipoprotein E E4 allele carriers were also more likely to be lost to follow-up (P = 0.01) and to demonstrate a thinner average mGCIPL complex (70.9 µm vs. 71.9 µm; P = 0.011) and pRNFL (77.6 µm vs. 79.2 µm; P = 0.045) after a minimum of 3 years of monitoring. Conclusions: The APOE E4 allele was associated with faster rates of mCGIPL complex thinning, particularly in eyes with NTG. These results suggest that the APOE E4 allele may be a risk factor for retinal ganglion cell degeneration in glaucoma.

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.

Classification of Visual Field Abnormalities in Highly Myopic Eyes without Pathologic Change.

PURPOSE: To develop a classification system of visual field (VF) abnormalities in highly myopic eyes with and without glaucoma. DESIGN: Secondary analysis of VF data from a longitudinal cohort study. PARTICIPANTS: One thousand eight hundred ninety-three VF tests from 1302 eyes (825 individuals). METHODS: All participants underwent VF testing (Humphrey 24-2 Swedish interactive threshold algorithm standard program; Carl Zeiss Meditec) and detailed ophthalmic examination. A comprehensive set of VF defect patterns was defined via observation of the 1893 VF reports, literature review, and consensus meetings. The classification system comprised 4 major types of VF patterns, including normal type, glaucoma-like defects (paracentral defect, nasal step, partial arcuate defect, arcuate defect), high myopia-related defects (enlarged blind spot, vertical step, partial peripheral rim, nonspecific defect), and combined defects (nasal step with enlarged blind spot). A subset (n = 1000) of the VFs was used to evaluate the interobserver and intraobserver agreement and weighted κ values of the classification system by 2 trained readers. The prevalence of various VF patterns and their associated factors were determined. MAIN OUTCOME MEASURES: The classification of VF in highly myopic eyes and its associated risk factors. RESULTS: We found that normal type, glaucoma-like defects, high myopia-related defects, and combined defects accounted for 74.1%, 10.8%, 15.0%, and 0.1% of all unique VF tests, respectively. The interobserver and intraobserver agreements were > 89%, and the corresponding κ values were 0.86 or more between readers. Both glaucoma-like and high myopia-related VF defects were associated with older age (odds ratios [ORs], 1.07 [95% confidence interval (CI), 1.04-1.10; P < 0.001] and 1.06 [95% CI, 1.04-1.10; P < 0.001]) and longer axial length (ORs, 1.65 [95% CI, 1.32-2.07; P < 0.001] and 1.37 [95% CI, 1.11-1.68; P = 0.003]). Longer axial length showed a stronger effect on the prevalence of glaucoma-like VF defects than on the prevalence of high myopia-related VF defects (P = 0.036). CONCLUSIONS: We propose a new and reproducible classification system of VF abnormalities for nonpathologic high myopia. Applying a comprehensive classification system will facilitate communication and comparison of findings among studies.

Comparative study of 2-year outcomes for Hydrus or iStent inject microinvasive glaucoma surgery implants with cataract surgery.

BACKGROUND: To compare real-world 24-month outcomes of phacoemulsification combined with either iStent inject or Hydrus Microstent. METHODS: Analysis of data from the Fight Glaucoma Blindness (FGB) international registry. Anonymized data from 344 eyes with mild-to-moderate open-angle glaucoma, normal-tension glaucoma or ocular hypertension that underwent phacoemulsification combined with either iStent inject (224) or Hydrus Microstent (120) were included. Data were adjusted for baseline characteristics using linear regression and propensity score matching. The primary endpoint was a comparison of mean intraocular pressure (IOP) at 24 months. RESULTS: At 24 months, there was no significant difference in IOP reduction between the two groups, consistent across all analyses. The matched cohort showed iStent inject achieved 3.1 mmHg reduction and Hydrus a 2.3 mmHg reduction (p = 0.530) and a mean medication reduction of 1.0 for iStent inject versus 0.5 for Hydrus (p = 0.081). 5.4% of eyes in the iStent inject group and 7.5% of eyes in the Hydrus group required subsequent procedures to improve IOP control within 24 months. Complications were rare with no significant differences between the groups. CONCLUSIONS: Twenty-four-month outcomes showed sustained IOP reduction with a good safety profile for both groups. There was no significant difference in IOP outcomes between the groups. There may be a small additional reduction in glaucoma medication usage following cataract surgery with iStent inject compared to Hydrus.

A Cost-Utility Analysis of Trabecular Bypass Devices Versus Usual Care for Patients With Open-Angle Glaucoma.

OBJECTIVE: The aim of this study was to determine whether insertion of a trabecular bypass device (TBD) is a cost-effective intervention for the treatment of open-angle glaucoma (OAG) with mild to moderate vision loss in the Australian setting. METHODS: We performed a cost-utility analysis of TBD implantation in conjunction with cataract surgery or as a standalone procedure in patients with OAG. The model used a Monte Carlo simulation to follow individual patients through a glaucoma treatment algorithm that included TBD and compared the costs and outcomes with those of patients simulated through an algorithm without TBD (usual care). The model tracked the intraocular pressure (IOP) of individual patients and then, based on this IOP, tracked the progression of the patient's glaucoma. Utility values were assigned dependent on severity of glaucoma. The analysis took the perspective of the Australian health care system. The main outcome was incremental cost per quality-adjusted life-year (QALY) of TBD versus usual care for the treatment of OAG. RESULTS: In the cataract surgery population, TBD surgery was associated with incremental healthcare costs of A$177 and 0.0726 QALYs per patient, resulting in an incremental cost per QALY gained of A$2430. In the standalone population, the overall incremental cost of TBD surgery versus usual care was A$2234. With QALYs gained of 0.1526 per patient, this equated to an incremental cost per QALY gained ratio of A$14,644. CONCLUSION: The incremental cost per QALY estimates for TBD were below thresholds generally accepted by Australian healthcare payers, suggesting that TBD is a cost-effective intervention for patients with primary OAG in the Australian setting.

eFOCUS 2: A randomised crossover trial of smartphone fundoscopy and direct ophthalmoscopy aiming to improve optic disc interpretation by medical students with e-learning support.

BACKGROUND: Ophthalmoscopy and its interpretation are complex. We aimed to compare the diagnostic accuracy of smartphone fundoscopy with traditional direct ophthalmoscopy for optic disc interpretation, with e-learning support. METHODS: We conducted a randomised, crossover study of 102 medical students. Students were offered e-learning for optic disc interpretation. A fundoscopy objective structured clinical examination was conducted after an introductory lecture and 10-min practical training session on smartphone fundoscopy and traditional ophthalmoscopy. Participants examined patients and simulator slides with a randomised crossover between smartphone [D-eye (Padova, Italy) or iExaminer (Welch Allyn, Macquarie Park, Australia)] and traditional ophthalmoscopy (Welch Allyn). Optic discs were graded independently by three masked ophthalmologists. The primary outcome was the ability to interpret an optic disc as normal or abnormal. Secondary outcomes included other optic disc aspects; student preferences; and e-learning performance. RESULTS: Students' agreement with the gold standard for an abnormal or normal disc was significantly greater using a smartphone (74.4%) than with direct ophthalmoscopy (68.1%, p = 0.032). More students preferred smartphone (74%) over direct ophthalmoscopy (26%, p < 0.001). E-learning led to an improvement in optic disc interpretation scores (mean improvement = 4.5%, 95% CI = 3.7-5.2, p < 0.001). CONCLUSIONS: Medical students are more accurate at recognising an abnormal optic disc using smartphone fundoscopy than traditional direct ophthalmoscopy, and have a strong preference for smartphone fundoscopy. E-learning may improve the interpretation of optic disc abnormalities. Smartphone fundoscopy may mitigate some technical challenges of fundoscopy and reinvigorate use of this valuable clinical examination.

Standalone iStent Trabecular Micro-bypass Glaucoma Surgery: A Systematic Review and Meta-Analysis.

PRECIS: Standalone trabecular micro-bypass glaucoma surgery with the iStent devices is associated with clinically relevant reductions in intraocular pressure (IOP) sustained over a reasonably long-term while simultaneously reducing medication burden and a relatively favorable safety profile. PURPOSE: While there is a relatively large body of evidence supporting the implantation of the iStent trabecular micro-bypass devices during phacoemulsification in patients with open-angle glaucoma (OAG), its efficacy as a standalone procedure has been less widely reported. The aims of this study were to systematically identify and quantitatively evaluate the efficacy of iStent devices (iStent and iStent inject) when performed independently of cataract surgery in patients with OAG. METHODS: A systematic review of the literature was undertaken in August 2019 to identify studies of standalone trabecular micro-bypass glaucoma surgery with iStent devices in patients with OAG. All randomized trials were considered and nonrandomized studies that included at least 6 months of follow-up or more than 10 eyes. Key efficacy analyses included postoperative IOP and medication use, which were used to evaluate weighted mean differences from baseline, and the proportion of eyes free of ocular medication. Postoperative adverse events were descriptively summarized. RESULTS: A total of 13 studies were identified including 4 randomized controlled trials and 9 nonrandomized or single-arm studies providing data for 778 eyes. In eyes implanted with iStent devices, a weighted mean IOP reduction of 31.1% was observed at 6 to 12 months. In studies reporting longer-term outcomes (36 to 48 mo or 60 mo), the weighted mean IOP reduction was 30.4% and 32.9%, respectively. The pooled weighted mean reduction in IOP from baseline across all studies at 6 to 12 months and 36 to 60 months poststent implantation was 7.01 mm Hg (95% confidence interval: 5.91, 8.11) and 6.59 mm Hg (95% confidence interval: 5.55, 7.63), respectively. Medication burden was reduced by ~1.0 medication at 6 to 18 months and 1.2 medications at 36 to 60 months. Adverse events reported in more than 5% of participants were progression of pre-existing cataract/cataract surgery and loss of best-corrected visual acuity but these rates were no different to those reported in comparator medical therapy study arms. CONCLUSIONS: The results from these studies support the independent effect of the iStent trabecular bypass devices on IOP and medication burden over a duration of follow-up of up to 5 years.

A Polygenic Risk Score Predicts Intraocular Pressure Readings Outside Office Hours and Early Morning Spikes as Measured by Home Tonometry.

PURPOSE: Intraocular pressure (IOP) elevations may occur in early morning or outside office hours and can be missed during routine in-clinic IOP measurements. Such fluctuations or peaks likely contribute to glaucoma progression. We sought to investigate the relationship between an IOP polygenic risk score (PRS) and short-term IOP profile. DESIGN: Cross-sectional study. PARTICIPANTS: Four hundred seventy-three eyes from 239 participants with suspected or established primary open-angle glaucoma sampled from 4 outpatient clinics in Australia between August 2016 and December 2019. METHODS: Participants underwent Icare HOME (Icare Oy, Vanda, Finland) tonometer measurements to record IOP 4 times daily for 5 days. Unreliable measurements were excluded. A minimum of 2 days with at least 3 reliable measurements were required. We used a validated IOP PRS derived from 146 IOP-associated variants in a linear regression model adjusted for central corneal thickness and age. MAIN OUTCOME MEASURES: Highest recorded early morning IOP and mean IOP within and outside office hours. Early morning IOP spikes were defined by a higher early morning IOP than the maximum in-office hours IOP. RESULTS: Reliable measurements were obtained from 334 eyes of 176 participants (mean age, 64 ± 9 years). Eyes in the highest IOP PRS quintile showed an early morning IOP increase of 4.3 mmHg (95% confidence interval [CI], 1.4-7.3; P = 0.005) and mean increase in IOP outside office hours of 2.7 mmHg (95% CI, 0.61-4.7; P = 0.013) than the lowest quintile, which were significant independently after accounting for a recent in-clinic IOP measured by Goldmann applanation tonometry. Eyes in the highest PRS quintile were 5.4-fold more likely to show early morning IOP spikes than the lowest quintile (odds ratio 95% CI, 1.3-23.6; P = 0.023). CONCLUSIONS: A validated IOP PRS was associated with higher early morning IOP and mean IOP outside office hours. These findings support a role for genetic risk prediction of susceptibility to elevated IOP that may not be apparent during in-clinic hours, requiring more detailed clinical phenotyping using home tonometry, the results of which may guide additional interventions to improve IOP control.

Corneal Stiffness Parameters Are Predictive of Structural and Functional Progression in Glaucoma Suspect Eyes.

PURPOSE: To investigate corneal stiffness parameters (SPs) as predictors of future progression risk in glaucoma suspect eyes. DESIGN: Prospective, longitudinal study. PARTICIPANTS: Three hundred seventy-one eyes from 228 primary open-angle glaucoma suspects, based on optic disc appearance, with normal baseline Humphrey Visual Field (HVF; Carl Zeiss Meditec) results. METHODS: Baseline corneal SPs were measured using Corvis ST (Oculus Optikgeräte GmbH). Participants were followed up every 6 months with clinical examination, HVF testing, and OCT. The baseline SP at first applanation (SP-A1) and highest concavity predicted the prospective outcome measures. MAIN OUTCOME MEASURES: Structural progression was measured by the OCT rate of thinning of the retinal nerve fiber layer (RNFL) and ganglion cell-inner plexiform layer (GCIPL). Functional progression was assessed by permutation analysis of pointwise linear regression criteria on HVF testing. RESULTS: Stiffness parameters correlated positively with central corneal thickness (CCT), which was adjusted for in all analyses. A higher SP-A1, suggestive of a stiffer cornea, was associated with a faster rate of RNFL thinning (P < 0.001), synergistic with thinner CCT (P = 0.004) over a mean follow-up of 4.2 years. Eyes with higher SP-A1 and thinner CCT (thin and stiff corneas) showed accelerated RNFL thinning by 0.72 µm/year relative to eyes with lower SP-A1 and thicker CCT (95% confidence interval [CI], 0.17-1.28; P = 0.011) and were at 2.9-fold higher likelihood of fast RNFL progression of more than 1 µm/year (95% CI, 1.4-6.1; P = 0.006). Consistent results also were observed with GCIPL thinning. Furthermore, a higher SP-A1 was associated with a greater risk of visual field progression (P = 0.002), synergistic with thinner CCT (P = 0.010). Eyes with higher SP-A1 and thinner CCT were at 3.7-fold greater risk of visual field progression relative to eyes with thicker CCT and lower SP-A1 (95% CI, 1.3-10.5; P = 0.014). CONCLUSIONS: Glaucoma suspect eyes with higher corneal SPs and lower CCT, suggestive of thin and stiff corneas, are at greater risk of progression. Corneal SPs seem to act synergistically with CCT as risk factors for glaucoma progression.

Cardiovascular Disease Predicts Structural and Functional Progression in Early Glaucoma.

PURPOSE: To investigate the association between cardiovascular disease and baseline structural defects and disease progression in glaucoma. DESIGN: Prospective, longitudinal study of preperimetric and perimetric glaucoma. PARTICIPANTS: Two thousand six hundred twenty-eight eyes from 1314 participants recruited to the Progression Risk of Glaucoma: Relevant SNPs with Significant Association (PROGRESSA) study were evaluated for baseline and longitudinal structural thinning using spectral-domain OCT and for visual field progression on Humphrey visual field (HVF) assessment. METHODS: Patients were classified as either predominantly macula ganglion cell-inner plexiform layer (mGCIPL), predominantly peripapillary retinal nerve fiber layer (pRNFL), or both mGCIPL and pRNFL structural change at enrollment, and then evaluated for longitudinal OCT or HVF progression. Cardiovascular disease and medication characteristics of the participants were compared with a reference group of stable patients. MAIN OUTCOME MEASURES: OCT and HVF baseline status and longitudinal progression. RESULTS: After accounting for age and cardiovascular characteristics, patients with predominantly mGCIPL thinning at baseline showed a higher prevalence of hypertension (odds ratio [OR], 2.70; 95% confidence interval [CI], 1.66-4.41; P < 0.001), antihypertensive use (OR, 2.03; 95% CI, 1.20-3.46; P = 0.008), and statin use (OR, 1.98; 95% CI, 1.07-3.66; P = 0.029) than reference patients. Patients with predominantly pRNFL thinning exhibited a comparable prevalence of cardiovascular disease or medication with reference patients. Review of longitudinal OCT and HVF data (mean follow-up, 5.34 ± 1.29 years) showed that hypertension was associated with an increased risk of both OCT (OR, 1.79; 95% CI, 1.17-2.75; P = 0.006) and HVF progression (OR, 1.92; 95% CI, 1.18-3.15; P = 0.013). A 1-standard deviation (approximately 21 mmHg) increase in systolic blood pressure at baseline was associated with a greater risk of OCT progression (OR, 1.27; 95% CI, 1.01-1.63; P = 0.041) and HVF progression (OR, 1.32; 95% CI, 1.01-1.73; P = 0.043). The association between systolic blood pressure and structural progression was comparable to that observed between intraocular pressure and structural progression (OR, 1.30; 95% CI, 1.01-1.67; P = 0.039). CONCLUSIONS: Cardiovascular disease is an important risk factor for glaucoma progression.

An Intraocular Pressure Polygenic Risk Score Stratifies Multiple Primary Open-Angle Glaucoma Parameters Including Treatment Intensity.

PURPOSE: To examine the combined effects of common genetic variants associated with intraocular pressure (IOP) on primary open-angle glaucoma (POAG) phenotype using a polygenic risk score (PRS) stratification. DESIGN: Cross-sectional study. PARTICIPANTS: For the primary analysis, we examined the glaucoma phenotype of 2154 POAG patients enrolled in the Australian and New Zealand Registry of Advanced Glaucoma, including patients recruited from the United Kingdom. For replication, we examined an independent cohort of 624 early POAG patients. METHODS: Using IOP genome-wide association study summary statistics, we developed a PRS derived solely from IOP-associated variants and stratified POAG patients into 3 risk tiers. The lowest and highest quintiles of the score were set as the low- and high-risk groups, respectively, and the other quintiles were set as the intermediate risk group. MAIN OUTCOME MEASURES: Clinical glaucoma phenotype including maximum recorded IOP, age at diagnosis, number of family members affected by glaucoma, cup-to-disc ratio, visual field mean deviation, and treatment intensity. RESULTS: A dose-response relationship was found between the IOP PRS and the maximum recorded IOP, with the high genetic risk group having a higher maximum IOP by 1.7 mmHg (standard deviation [SD], 0.62 mmHg) than the low genetic risk group (P = 0.006). Compared with the low genetic risk group, the high genetic risk group had a younger age of diagnosis by 3.7 years (SD, 1.0 years; P < 0.001), more family members affected by 0.46 members (SD, 0.11 members; P < 0.001), and higher rates of incisional surgery (odds ratio, 1.5; 95% confidence interval, 1.1-2.0; P = 0.007). No statistically significant difference was found in mean deviation. We further replicated the maximum IOP, number of family members affected by glaucoma, and treatment intensity (number of medications) results in the early POAG cohort (P ≤ 0.01). CONCLUSIONS: The IOP PRS was correlated positively with maximum IOP, disease severity, need for surgery, and number of affected family members. Genes acting via IOP-mediated pathways, when considered in aggregate, have clinically important and reproducible implications for glaucoma patients and their close family members.

Effect of phacoemulsification cataract surgery on intraocular pressure in early glaucoma: A prospective multi-site study.

IMPORTANCE: Cataract and primary open-angle glaucoma (POAG) commonly co-exist, and cataract surgery is thought to reduce intraocular pressure (IOP), the major modifiable risk factor of POAG. BACKGROUND: Previous studies exploring the effect of cataract surgery on IOP are limited by retrospective design, lack of a control group, medication use and washout and loss to follow up. DESIGN: Prospective, multicentre, matched case-control Australian study. PARTICIPANTS: 171 eyes of 108 POAG patients who underwent cataract surgery, matched to 171 control eyes. METHODS: Serial longitudinal IOP measurements were compared before and after cataract surgery, and relative to the controls. A mixed-effect model was used for the longitudinal data. MAIN OUTCOME MEASURES: Change in IOP. RESULTS: The mean follow-up time was 4.8 (1.4) years. Cataract surgery reduced mean IOP by 2.22 mmHg (95% confidence interval: 1.93-2.52 mmHg, P < .001) with 59 eyes (34%) achieving at least 3 mmHg reduction. Compared to matched controls, the mean reduction in IOP was 1.75 mmHg (95% confidence interval 1.15-2.33 mmHg; P < .001). Higher preoperative IOP and being on fewer topical glaucoma medications preoperatively were strongly predictive of a larger IOP reduction in a multivariable model. Anterior chamber depth was not associated with IOP reduction. Eyes with preoperative IOP ≥24 mmHg had a mean IOP reduction of 4.03 mmHg with 81% experiencing at least 3 mmHg reduction. Sub-analysis of medication naïve and pseudoexfoliation patients showed similar results. CONCLUSIONS AND RELEVANCE: Cataract surgery has a confirmed effect in reducing IOP in a "real world" setting of early glaucoma patients.

Multitrait analysis of glaucoma identifies new risk loci and enables polygenic prediction of disease susceptibility and progression.

Glaucoma, a disease characterized by progressive optic nerve degeneration, can be prevented through timely diagnosis and treatment. We characterize optic nerve photographs of 67,040 UK Biobank participants and use a multitrait genetic model to identify risk loci for glaucoma. A glaucoma polygenic risk score (PRS) enables effective risk stratification in unselected glaucoma cases and modifies penetrance of the MYOC variant encoding p.Gln368Ter, the most common glaucoma-associated myocilin variant. In the unselected glaucoma population, individuals in the top PRS decile reach an absolute risk for glaucoma 10 years earlier than the bottom decile and are at 15-fold increased risk of developing advanced glaucoma (top 10% versus remaining 90%, odds ratio = 4.20). The PRS predicts glaucoma progression in prospectively monitored, early manifest glaucoma cases (P = 0.004) and surgical intervention in advanced disease (P = 3.6 × 10-6). This glaucoma PRS will facilitate the development of a personalized approach for earlier treatment of high-risk individuals, with less intensive monitoring and treatment being possible for lower-risk groups.