The Ocular Hypertension Treatment Study: baseline factors that predict the onset of primary open-angle glaucoma

Comparison of Deep Learning and Clinician Performance for Detecting Referable Glaucoma from Fundus Photographs in a Safety Net Population

Purpose

Develop and test a deep learning (DL) algorithm for detecting referable glaucoma.

Design

Retrospective cohort study.

Participants

A total of 6116 patients from the Los Angeles County (LAC) Department of Health Services (DHS) were included.

Methods

Fundus photographs and patient-level labels of referable glaucoma (cup-to-disc ratio ≥0.6) provided by 21 certified optometrists. A DL algorithm based on the Visual Geometry Group-19 architecture was trained using patient-level labels generalized to images from both eyes. Area under the receiver operating curve (AUROC), sensitivity, and specificity were calculated to assess algorithm performance using an independent test set that was also graded by 13 clinicians with 0 to 10 years of experience. Algorithm performance was tested using reference labels provided by either LAC DHS optometrists or an expert panel of 3 glaucoma specialists.

Main Outcome Measures

Area under the receiver operating curve, sensitivity, and specificity.

Results

The DL algorithm was trained using 12 998 images from 5616 patients (2086 referable glaucoma, 3530 nonglaucoma). In this data set, the mean age was 56.8 ± 10.5 years with 54.8% women, 68.2% Latinos, 8.9% Blacks, 6.0% Asians, and 2.7% Whites. One thousand images from 500 patients (250 referable glaucoma, 250 nonglaucoma) with similar demographics (P ≥ 0.57) were used to test the algorithm. Algorithm performance matched or exceeded that of all independent clinician graders in detecting patient-level referable glaucoma based on LAC DHS optometrist (AUROC = 0.92) or expert panel (AUROC = 0.93) reference labels. Clinician grader sensitivity (range, 0.33-0.99) and specificity (range, 0.68-0.98) ranged widely and did not correlate with years of experience (P≥ 0.49). Algorithm performance (AUROC = 0.93) also matched or exceeded the sensitivity (range, 0.78-1.00) and specificity (range, 0.32-0.87) of 6 certified LAC DHS optometrists in the subsets of the test data set they graded.

Conclusions

A DL algorithm for detecting referable glaucoma trained using patient-level data provided by certified LAC DHS optometrists approximates or exceeds performance by ophthalmologists and optometrists, who exhibit variable sensitivity and specificity unrelated to experience level. Implementation of this algorithm in screening workflows could help reallocate resources and provide more reproducible and timely glaucoma care.

Financial Disclosures

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Reliability of Self-Monitoring of Intraocular Pressure With iCare Home2 Rebound Tonometry

PRCIS

Using iCare Home2 (iCare, Finland) rebound tonometry, self-measurement of intraocular pressure has demonstrated good reliability and ease of use.

PURPOSE

To investigate the reliability and repeatability of self-measured intraocular pressure (IOP) with rebound tonometry using iCare Home2.

PATIENTS AND METHODS

One hundred four patients out of 110 consecutive patients were recruited for this observational cross-sectional study. One randomly selected eye from each patient underwent 6 consecutive IOP measurements with Goldmann applanation tonometry (GAT), iCare IC200, and iCare Home2. Every eye was tested twice with each device, in random order, by an ophthalmologist for GAT and IC200, and by the patient itself for Home2. In addition, central corneal thickness (CCT) has been collected. The reliability of Home2 has been tested by calculating limits of agreement (LoA) between self-measured and physician-measured IOP, using the Bland-Altman analysis. The repeatability of each device has been tested by calculating the limits of repeatability (LoR) with the same method. Pearson correlation coefficient was used to determine the correlation between differences in IOP measurements and CCT.

RESULTS

The mean difference between GAT and iCare Home2 was -0.28±1.57 mmHg ( P =0.070), 95%-LoA: (-3.36 to 2.79 mmHg). The mean difference between IC200 and iCare Home2 was 0.92±1.48 mmHg ( P <0.0001), 95%-LoA (-1.98 to 3.82 mmHg). The mean difference between the first and second measurements with GAT, iCare IC200, and iCare Home2 measurements was 0.21±0.98 mmHg ( P =0.03), -0.02±1.11 mmHg ( P =0.88) and -0.23±1.04 mmHg ( P =0.05).

CONCLUSIONS

Self-measured IOP with rebound tonometry showed good reliability and repeatability when compared with physician-measured IOP with both standard GAT and rebound tonometry.

"Optic nerve of steel": A case of very high intraocular pressures with markedly little visual field progression over years

Purpose

We report a case of pseudoexfoliation glaucoma with exceedingly high intraocular pressures (IOP) but limited visual field progression despite poor adherence with treatment over a 7-year period.

Observation

A 67-year-old Eastern European female presented to the emergency room with an IOP of 52 mmHg OD and exam findings consistent with pseudoexfoliation glaucoma. Subsequent testing demonstrated superior and inferior arcuate deficits on Humphrey visual field (HVF) testing and corresponding thinning of optic nerve OD. The patient was very inconsistent with topical glaucoma medications, and after undergoing selective laser trabeculoplasty she was lost to follow-up without any additional treatment. She returned one year later with an IOP of 59 mmHg, but remarkably stable HVF. The patient refused to restart glaucoma drops and elected instead to proceed with a trabeculectomy OD, which was successfully performed, with the final visual acuity of 20/25 and IOP of 20 mmHg OD. The patient was again lost to follow-up for three years. Her IOP was 40 mmHg OD on return to clinic, but her glaucoma testing revealed very little progression. She decided to pursue placement of glaucoma drainage device (Baerveldt 350) OD, and her IOP was 18 mmHg OD after 6 months on no medications. The patient was lost to follow-up thereafter.

Conclusions

The limited visual field progression with chronically high IOP over years strongly argues in favor of IOP-independent mechanisms contributing to pathophysiology of glaucoma. This case also highlights the importance of longitudinal monitoring and tailoring glaucoma therapy holistically to individual patient circumstances.

Prevalence and Risk Factors of Primary Angle Closure Disease in an Adult Chinese American Population: The Chinese American Eye Study

OBJECTIVE

To assess the prevalence and risk factors of primary angle closure disease (PACD) among adult Chinese Americans.

DESIGN

Cross-sectional population-based study.

PARTICIPANTS

Total 4582 Chinese Americans 50 years and older from 15 census tracts in Monterey Park, CA.

METHODS

Participants received complete eye exams, including gonioscopy, fundus photography, and standard automated perimetry. Primary angle closure suspect (PACS) was defined as non-visible posterior trabecular meshwork for ≥270° on gonioscopy. Primary angle closure (PAC) was defined as PACS with peripheral anterior synechiae (PAS) and/or IOP≥21 mmHg without glaucomatous neuropathy (GON). PACG was defined as PACS or PAC with GON. Suspected PACG (sPACG) was defined as GON without PACS or PAC but with evidence of prior laser iridotomy or cataract surgery with residual PAS. Multivariable logistic regression models were developed to identify risk factors for PACS, PAC, and PACG.

MAIN OUTCOME MEASURES

Prevalence and risk factors of PACS, PAC, and PACG.

RESULTS

Data from 4,310 CHES participants were included in the analysis. The prevalence of PACS, PAC, and PACG were 8.1% (95% CI: 7.3%-9.0%; N = 351), 3.1% (95% CI: 2.6%-3.6%; N = 132), and 1.1% (95% CI: 0.8%-1.4%; N = 46), respectively. Prevalence of PACG and sPACG combined was 1.8% (95% CI: 1.4%-2.2%; N = 76). Older age (OR=1.06 per year), positive family history of glaucoma (OR=3.21), higher IOP (OR=1.17 per mmHg), and shorter axial length (OR=1.67 per mm) were significant risk factors (P < .003) for PACG on multivariable analysis. 75.0% of PACG cases were previously undiagnosed. There was one case of PACG with unilateral blindness and no cases with bilateral blindness.

CONCLUSION

PACG prevalence was not substantially lower among Chinese Americans compared to mainland Chinese. Older age, higher IOP, positive family history of glaucoma, and smaller AL conferred higher risk. While the majority of PACG cases were undetected, blindness was rare. Improved access to eye care and cataract surgery appears to mitigate severe visual morbidity associated with PACG.

Changes in individuals' glaucoma progression velocity after IOP-lowering therapy: A systematic review

Primary open-angle glaucoma (POAG) is a chronic progressive optic neuropathy often associated with increased intraocular pressure (IOP). Monitoring glaucoma progression velocity, for example, the rate of change in global indices such as mean deviation (MD), is a common way to determine whether functional deterioration has occurred. This systematic review aims to assess changes in glaucoma progression velocity in response to IOP-lowering therapy at an individual level. A systematic review was conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. A comprehensive search of PubMed, Cochrane CENTRAL, and ClinicalTrials.gov from database inception through November 12, 2023, was conducted for randomized clinical trials involving patients with POAG, normal tension glaucoma, or progressive ocular hypertension who received IOP-lowering therapy with a target IOP reduction ≥20% from baseline. Included trials were required to report visual field progression velocity information for individual patients before and after intervention. One study was found to meet inclusion criteria and, therefore, synthesis of data and meta-analysis were unable to be performed. The study reports on 139 eyes of 109 patients from the Ocular Hypertension Treatment Study who reached a POAG endpoint. In these patients, the post-treatment rate of MD change (-0.27 ± 0.7 dB/year) was significantly slower than the pre-treatment rate (-0.51 ± 0.8), P < 0.01. In addition, the rate of MD change significantly correlated with mean IOP reduction (p < 0.001). The singular study demonstrated that IOP-lowering therapy did variably slow glaucoma progression rate in that patient cohort. There is a need for more studies that focus on individual patients' responses to glaucoma treatment. Furthermore, this information should be used to classify the magnitude of patients' responsiveness to IOP reduction. Future studies should report pre- and post-intervention progression velocities.

Medical and surgical treatment management in open angle glaucoma patients of Asian descent: A narrative review

Glaucoma represents a progressive optic neuropathy characterized by optic nerve head damage, retinal nerve fiber layer thinning and visual field loss. There are significant disparities in the diagnosis, disease progression and treatment outcomes of glaucoma patients. Primary open angle glaucoma (OAG) patients of African descent have been found to have earlier and more severe disease than those of European descent. In 2020, half of the worldwide glaucoma patient population resided in Asia, where normal-tension and angle-closure glaucoma are more prevalent. The significant prevalence and diversity of OAG in Asia necessitates a better understanding of medical, laser, and surgical management in this growing population. PubMed and Embase database searches were conducted for all pertinent articles and abstracts published between January 1990 through January 2024 and review of the literature yielded 1,237 potential articles, from which 104 met the inclusion/exclusion criteria. The current literature suggests that prostaglandin analogues are efficacious and safe in OAG Asian patients, however little is known on other classes of hypotensive drugs. Published data on the laser and surgical management of glaucoma in Asian populations describe differences in outcomes between Asian and Caucasian populations including from minimally invasive glaucoma surgery. Longitudinal studies specifically designed to investigate treatment impact while accounting for access to care in the increasing global aging Asian population are warranted.

Spectralis Optical Coherence Tomography for Evaluating Ocular Hypertensive and Glaucoma Suspect Eyes: Real-World Data from Taiwan

Objectives: The aim of this research was to evaluate the diagnostic performance of Spectralis optical coherence tomography (OCT) parameters for ocular hypertensive (OH) and glaucoma suspect (GS) eyes in an Asian population from Taiwan. Methods: This retrospective cross-sectional study included 258 OH (mean deviation [MD]: -1.10 ± 1.75 dB), 380 GS (MD: -1.24 ± 2.63 dB), and 742 normal (MD: -1.47 ± 3.29 dB) eyes. The diagnostic performance of Spectralis OCT parameters, including optic nerve head (ONH) and macular parameters, was compared among groups. The area under the receiver operating characteristic curve (AUC) of each parameter signified its power to differentiate between normal and OH or GS eyes. Results: In various scanning protocols, circumpapillary retinal nerve fiber layer (NFL)-temporal (AUC = 0.538), macular NFL-outer temporal (AUC = 0.611), and retinal average thickness (RAT)_1.8 (AUC = 0.578) were the best parameters in distinguishing OH eyes from normal eyes. Moreover, minimum rim width (MRW)-mean global (AUC = 0.737), macular NFL-outer temporal (AUC = 0.558), and RAT_2.8 (AUC = 0.543) were the best parameters in distinguishing GS eyes from normal eyes. After adjusting for age and refraction effects, we determined that the AUCs for OH and GS were 0.694 and 0.646, respectively. Conclusions: Our real-world data indicate that Spectralis OCT parameters show some potential for early glaucoma detection and monitoring, but their current diagnostic effectiveness remains limited. When managing OH eyes, caution is required in evaluating macular retinal NFL thickness in addition to the ONH. Bruch's membrane opening-MRW is a potential objective indicator of ONH changes in GS eyes.

Validation of iCare IC200® rebound tonometry for intraocular pressure measurement

PURPOSE

To validate the measurement of intraocular pressure (IOP) using rebound tonometry (RT) compared to Goldmann applanation tonometry (GAT).

METHODS

We measured air puff tonometry (AT) with estimation of pachymetry, then IOP using GAT and RT in adult patients. We measured internal validity (agreement with Lin concordance coefficient-LCC, sensitivity and specificity for ocular hypertension (IOP threshold>21mmHg) and external validity (depending on pachymetry and body mass index) and determined the most comfortable method for the patients.

RESULTS

We included 341 eyes of 171 patients (73.2±10.7 years old, 52.1% men). Mean IOP was 16.5±4.7mmHg for RT and 16.2±4.1mmHg for GAT. Mean IOP difference between RT and GAT was 0.31±1.43mmHg; LCC was 0.95 (0.94 to 0.96, P=0.005). The prevalence of eyes with an IOP measurement >21mmHg was 15.5% for RT and 12.6% for GAT. Sensitivity and specificity of RT were 86% (71.1% to 94.7%) and 94.6% (91.4% to 96.9%) respectively. Depending on pachymetry, LCC was 0.98 (0.98 to 0.99), 0.94 (0.91 to 0.97), 0.94 (0.92 to 0.96), and 0.88 (0.83 to 0.93) between RT and GAT, respectively for the 4 pachymetry groups (<500, 500-520, 520-560, >560μm). Results were similar across BMI ranges (<25, 25-30, 30-35, >35). The most comfortable method was RT for 87% of patients.

CONCLUSION

RT is highly reliable in adult IOP measurement and independent of pachymetry and BMI.

Risk Factors for Diagnostic Change from Glaucoma Suspect to Primary Open-Angle Glaucoma and Vice Versa Over 2 Years

OBJECTIVE

This study investigates the incidence and causes of diagnostic changes from primary open-angle glaucoma suspect (POAGS) to primary open-angle glaucoma (POAG), and vice versa, in clinical practice.

DESIGN

This is a retrospective, single-site, case-control study.

PARTICIPANTS

It includes patients > 40 years of age diagnosed with either POAG or POAGS between 2013 and 2020. Controls had a minimum of 24 months of follow-up without a diagnostic change, whereas cases underwent a diagnostic change from glaucoma to suspect (POAG to POAGS) or from suspect to glaucoma (POAGS to POAG) within 2 years.

METHODS

At initial and follow-up visits, diagnosis, treatment, type of ophthalmic provider, and performance of pachymetry, visual fields (VFs), OCT, disc examination, and gonioscopy were recorded.

MAIN OUTCOME MEASURES

Data were then analyzed to determine if baseline characteristics, type of provider seen, or ophthalmic testing performed were protective or risk factors in regards to diagnostic change.

RESULTS

Nine hundred twenty-two subjects were included, and the incidence of diagnostic changes was 13.8% (127/922), of which 99 (78%) were upstaged from POAGS to POAG and 28 (22%) changed from POAG to POAGS. Pre-existing nonglaucomatous VF defect (P < 0.001) was significantly higher in cases than controls. Cases were significantly less likely to be seen by a glaucoma specialist at the initial visit compared with controls (P < 0.001), and less cases underwent VF testing (P < 0.001), OCT testing (P = 0.017), or gonioscopy (P = 0.013) at the initial visit. On multivariate analysis, performing VFs or OCT at both visits reduced the odds of short-term diagnostic change, whereas changing providers from a nonglaucoma specialist to a glaucoma specialist between visits increased the odds of diagnostic change. In the POAG-to-POAGS cases, 39% (11/28) were treated with either medications or laser trabeculoplasty, whereas 72% (71/99) of the POAGS-to-POAG cases were left untreated between visits.

CONCLUSIONS

It is important to understand risk factors for diagnostic changes in glaucoma, in order to prevent undertreatment of disease and overtreatment of suspects. Here we find specialist type and adherence to American Academy of Ophthalmology (AAO) recommended testing to be important factors in preventing short term diagnostic changes.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Optic Disc Microvasculature Reduction and Visual Field Progression in Primary Open-Angle Glaucoma

PURPOSE

To investigate the relationship between optic disc vessel density (ODVD) reduction and visual field (VF) progression in primary open-angle glaucoma (POAG) patients.

DESIGN

Retrospective case series.

METHODS

A total of 187 POAG eyes underwent ≥5 consecutive VF, spectral-domain optical coherence tomography, and swept-source OCT angiography imaging sessions during ≥3 years of follow-up. ODVD reduction was defined as a statistically significant negative slope (P < .05) of ODVD, calculated as the ratio of pixels occupied by vessels within the temporal optic disc area for any global, superior, or inferior sectors. The association between VF progression and rate of ODVD change was assessed by logistic regression and multivariable longitudinal linear mixed-effects models vs time.

RESULTS

During 3.67 ± 0.38 years of follow-up on the 187 eyes, 90 (48.1%) and 56 (29.9%) showed ODVD reduction and VF progression, respectively. A higher proportion of eyes with ODVD reduction had VF progression than did those without ODVD reduction (51/90 eyes [56.7%] vs 5/97 eyes [5.2%]; P < .001). VF progression was associated with a faster rate of global ODVD change (odds ratio, 5.10; P = .002) as well as a faster rate of global retinal nerve fiber layer thinning (odds ratio, 39.6; P = .008) in the multivariable model.

CONCLUSIONS

Optic disc microvasculature reduction was associated with VF progression even after adjusting for possible influencing factors including retinal nerve fiber layer thinning in POAG. This suggests that deep optic nerve head circulation has a role in the pathogenesis of glaucoma.

Intraocular Pressure Measurements With the Tono-Vera: A New Handheld Rebound Tonometer

PRCIS

In a cross-sectional study comparing the novel Tono-Vera handheld rebound tonometer with the Ocular Response Analyzer, a strong agreement was found between the intraocular pressure measurements of the 2 devices.

PURPOSE

To compare intraocular pressure (IOP) measurements obtained by the new Tono-Vera (Reichert Technologies), a novel handheld rebound tonometer with a proprietary camera-based positioning system, with those from the Ocular Response Analyzer (ORA, Reichert Technologies) non-contact tonometer.

PATIENTS

Fifty-four eyes of normal individuals and open angle glaucoma subjects.

METHODS

All subjects had at least 6 reliable measurements with the Tono-Vera and 3 with the ORA, acquired by the same technician in the same visit. The sample was randomly split into calibration and validation samples. An ordinary least squares linear regression model generated a calibration formula for Tono-Vera readings using ORA's Goldmann-correlated IOP (IOPg) as a target. Bland-Altman plots evaluated the agreement between Tono-Vera calibrated IOP (IOPtv) and ORA IOPg in the validation sample.

MAIN OUTCOME MEASURES

Agreement between IOPtv and IOPg measurements.

RESULTS

Fifty glaucoma and 4 normal eyes were included, mean age 68.3 ± 9.4 years, mean central corneal thickness 535.0 ± 39.6 μm. In the validation sample, mean IOPtv was 14.6 ± 5.2 mmHg (range, 7.4-28.5 mmHg) versus 15.0 ± 5.3 mmHg (range, 6.6-28.6 mmHg) for ORA IOPg ( R ² = 0.782). Bland-Altman plots showed a mean difference of -0.4 ± 2.5 mmHg (95% limits of agreement: -5.4 to 4.5 mmHg). 58.6%, 79.3%, and 96.5% of IOPtv measurements fell within ± 2, ± 3, and ± 5 mmHg of ORA measurements. No fixed or proportional biases were observed ( P = 0.620).

CONCLUSION

There was a strong correlation and agreement in IOP measurements between calibrated Tono-Vera IOP and ORA IOPg.

Twelve-Month Outcomes of Combined Phacoemulsification with Ab Interno Canaloplasty Versus Single-Use Dual Blade Goniotomy in Glaucoma Patients

BACKGROUND

To compare the efficacy and safety of combined phacoemulsification with ab interno canaloplasty (Phaco-AbiC) versus single-use dual blade goniotomy (Phaco-DBG).

MATERIAL AND METHODS

In this prospective consecutive case series, intraocular pressure (IOP), the number of IOP-lowering medications, the mean deviation (MD) of visual field testing, and surgery-related complications were evaluated in 25 eyes following Phaco-AbiC and 20 eyes following Phaco-DBG through 12 months of follow-up. Qualified or complete success was defined as postoperative IOP lower than 21, 18, and 16 mmHg with or without IOP-lowering medications.

RESULTS

At the 12-month follow-up, IOP was significantly reduced compared to baseline in the Phaco-AbiC (14.2 ± 2.7 versus 19.2 ± 4.7 mmHg, p < 0.001) and Phaco-DBG groups (16.7 ± 3.4 versus 19.9 ± 3.9 mmHg, p < 0.001). At the 12-month follow-up, IOP was significantly higher following Phaco-DBG than Phaco-AbiC (p = 0.011). Compared to baseline, the number of IOP-lowering medications was significantly reduced in the Phaco-AbiC (1.2 ± 1.4 versus 2.4 ± 1.0, p < 0.001) and Phaco-DBG groups (0.8 ± 0.9 versus 2.1 ± 0.9, p < 0.001) at the 12-month follow-up. For IOP lower than 16 mmHg, the complete and qualified success rate was significantly higher following Phaco-AbiC (36.0 and 76.2%, respectively) than Phaco-DBG (17.5 and 40.6%; p = 0.037; p = 0.007, respectively). No severe intra- or postoperative complications occurred.

CONCLUSION

Both Phaco-AbiC and Phaco-DBG achieved a significant reduction in IOP and IOP-lowering medications at the 12-month follow-up. IOP was significantly lower 12 months following Phaco-AbiC than Phaco-DBG.

Agreement and Reliability of Transpalpebral Tonometers with Goldmann Applanation Tonometer: A Systematic Review and Meta-analysis

TOPIC

The systematic review and meta-analysis consolidates the extant body of evidence comparing reliability and agreement between transpalpebral tonometers (TTs) and Goldmann applanation tonometer (GAT).

CLINICAL RELEVANCE

With a global prevalence of 3.54 percent, glaucoma stands as the second leading cause of preventable blindness. Projections indicate a rise to 111 million cases by 2040. Existing literature presents inconsistent findings while comparing TT and GAT. The derivation of summary estimates assessing their agreement holds significance, given TT's multifaceted applicability in clinical, community, and home settings.

METHODS

Systematic review was conducted using PubMed, Cochrane Library, and Google Scholar from January 2000 to December 2022. Two reviewers independently evaluated, enumerated, and extracted studies and data based on eligibility criteria. The Quality Assessment for Diagnostic Accuracy Studies checklist was used to assess study quality. The summary measures were pooled using the random-effects model as mean difference (MD), and 95% limits of agreement (LoA). We assessed heterogeneity using the I2 statistic. The study protocol was registered with the International Prospective Register of Systematic Reviews (CRD42022321693).

RESULTS

A total of 26 methods comparison studies (3577 eyes) were included in the meta-analysis. The overall random-effects MD (TT - GAT) and standard deviation (SD) for intraocular pressure (IOP) were -0.70 ± 4.32 mmHg (95% LoA: -8.74 to 7.33 mmHg). In the subgroup analysis based on index test devices used, Easyton showed the lowest MD, SD, (-0.29 ± 2.35 mmHg), and 95% LoA (-4.90 to 4.32 mmHg). In the univariate meta-regression model, we found that, on average, studies examining normal eyes reported a statistically significant lower MD of 2.67 mmHg (95% confidence interval: 0.27-5.07 mmHg; P = 0.03) between TT and GAT, compared to studies that assessed eyes with mixed ocular condition.

CONCLUSION

In the current meta-analysis, we found a small MD in the measured IOP between the 2 tonometers. However, given the high heterogeneity and a wider LoA, it is not advisable to use TT interchangeably with GAT.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Intraocular pressure correlation to progressive retinal nerve fiber layer loss in primary open angle glaucoma as measured by standard and modified goldmann applanation tonometers

PURPOSE

Characterize the relationship between intraocular pressure (IOP) as measured by standard and modified Goldmann prisms and the progressive loss of retinal nerve fiber layer (RNFL) in a cohort of glaucoma patients.

DESIGN

Retrospective cross-sectional cohort data analysis.

PARTICIPANTS

The study included all patients from a database of 1927 eyes, 966 patients with same visit sequential standard and modified Goldmann IOP measurements. From the database, 148 eyes, 75 patients met the inclusion criteria of a diagnosis of primary open angle glaucoma (POAG) with at least 5 sequential quality optical coherence tomographer (OCT) measurements.

METHODS

Sequential OCT images were obtained with the spectral domain Zeiss OCT5000. Participants were all diagnosed with POAG by untreated IOP ≥ 22, disk changes, and visual field (HVF) loss consistent with glaucomatous optic neuropathy (GON). Included were 575 Goldmann IOP measurements with standard and modified prisms affixed to the Goldmann applanation tonometer (GAT) armature. A modified prism includes a corneal conforming applanation surface minimizing the cornea's contribution to the IOP measurement. The study included a total of 940 OCT visits with an average of 6.3 visits per eye over an average of 4.9 years. Retinal nerve fiber layer (RNFL) loss rate was calculated by serial linear fit of average RNFL thickness measurements. Demographics as well as central corneal thickness (CCT) and corneal hysteresis (CH) data were also collected.

OUTCOME MEASURES

Pearson correlation coefficients and random coefficient models were used to evaluate the relationship between mean standard and modified IOP measurements and RNFL thickness measurements over time in POAG subjects. Secondary outcomes of CCT and CH correlation to RNFL were similarly analyzed.

RESULTS

For all 148 POAG eyes, the overall rate of RNFL loss for an average standard GAT IOP of 17.9 mmHg was 1.08 µm per year (p = 0.002). Each 1-mmHg increase in standard GAT IOP was associated with an additional RNFL loss of 0.047 µm per year (r = 0.153, p = 0.06). Each 1-mmHg increase in modified GAT IOP was associated with an additional RNFL loss of 0.084 µm per year (r = 0.289, p = 0.0005). A modified prism IOP measurement ≥ 22 mmHg indicates a 2.57 times greater probability of significant RNFL loss than a standard prism IOP measurement ≥ 22 mmHg, p < 0.0001.

CONCLUSIONS

Higher levels of GAT IOP during follow-up were related to higher rates of progressive RNFL loss detected by optic nerve OCT in treated POAG. A modified GAT prism surface demonstrates a significantly increased sensitivity, reliability and differentiation to progressive RNFL loss when compared to a standard GAT prism measured IOP. PRéCIS: A modified applanation surface prism with a corneal conforming shape used on a Goldmann tonometer appears to be a more sensitive and reliable indicator of progressive glaucomatous optic neuropathy as measured by retinal nerve fiber layer changes.

Risk for ocular hypertension progression to early glaucoma: A predictive model and key predictors

BACKGROUND

Ocular hypertension (OHT) is the most significant risk factor for glaucoma. We aimed to develop a model for predicting OHT progression to early glaucoma and to identify key predictors.

METHODS

Patients with OHT with at least two follow-up visits within 3 years were categorized into non-progressive and progressive groups based on optic nerve morphology and/or functional changes during follow-up. Data were split into training and testing sets (8:2 ratio). Least absolute shrinkage and selection operator regression and logistic regression were used to select predictors. Machine learning models were constructed using the selected predictors as input and evaluated using area under the receiver operating characteristic (AUC) and precision-recall (AP) curve values. The optimal model was further evaluated using 10-fold cross-validation and a validation set. The Shapley additive explanations method was applied to interpret the predictors.

RESULTS

Overall, 395 eyes from 395 patients were included (non-progressive: n = 295; progressive: n = 100). The random forest model outperformed all others, achieving AUC values of 0.881 (95 % confidence interval [CI]: 0.835-0.926) in the training set and 0.937 (95 % CI: 0.884-0.991) in the testing set. In the independent validation set (n = 82), the AUC and AP values were 0.865 (95 % CI: 0.782-0.947) and 0.707, respectively. Key predictors were baseline intraocular pressure, rim area, ganglion cell-inner plexiform layer (GCIPL) inferior-temporal thickness difference, and GCIPL superior-temporal thickness difference. Family history and male sex also contributed.

CONCLUSIONS

The developed model could effectively predict the risk for OHT progression to early glaucoma and may aid devising individualized treatment plans and follow-up protocols.

Associations between Clustered Visual Field Progression and Locations of Disc Hemorrhages in Glaucoma: A Three-year Prospective Study

PURPOSE

To evaluate the impact of disc hemorrhages (DHs) at different locations on clustered visual field (VF) progression in patients with primary open-angle glaucoma (POAG) over a 3-year prospective study.

DESIGN

A prospective, multicenter cohort study.

PARTICIPANTS

Patients diagnosed with POAG and intraocular pressure (IOP) ≤18 mmHg undergoing prostaglandin analog monotherapy.

METHODS

VF testing, IOP measurements, fundus photography, and optical coherence tomography (OCT) scans were conducted quarterly over a 3-year period. DH locations were categorized into superior, inferior, temporal, and nasal quadrants. The VF was subdivided into superior, inferior, and central regions, with the central VF further divided into superior central and inferior central zones. A multivariable linear mixed-effects model with random intercepts and slopes was employed to analyze the relationship between DH history at specific locations and progressive changes in clustered total deviation (TD).

MAIN OUTCOME MEASURES

Association between DH location and the rate of clustered VF progression.

RESULTS

Among 186 eyes from 109 patients, DH occurred in 61 eyes (32.8%). Superior, inferior, temporal, and nasal DH were observed in 19, 31, 21, and 2 eyes, respectively. Faster superior TD slope was significantly associated with inferior DH (P=0.032), but not with superior or temporal DH. A faster inferior TD slope was significantly associated with a worse inferior baseline TD value (P=0.009) and marginally associated with superior DH (P=0.053) but not with inferior or temporal DH. A faster central TD slope was significantly associated with temporal DH (P<0.001) and inferior DH (P=0.032) but not with superior DH. Detailed analysis revealed that inferior DH was significantly associated with the superior central TD slope (P=0.010), but not with the inferior central TD slope. Although DH recurrence was observed in 33 eyes, the number of DH events did not show an additive effect on corresponding clustered VF progression.

CONCLUSIONS

The location of DH was strongly associated with corresponding clustered VF progression in patients with POAG. Both temporal and inferior DH represent risk factors for central VF progression.

Association Between Cup-to-Disc Ratio and Structural and Functional Damage Parameters in Glaucoma: Insights From Multiparametric Modeling

Purpose

To model the association between vertical cup-to-disc ratio (CDR) and clinically relevant glaucomatous outcomes.

Methods

From a tertiary glaucoma clinic, clinician-estimated CDR, CDR derived from peripapillary optical coherence tomography scans, circumpapillary retinal nerve layer thickness, optic disc diameter, visual field (VF) mean deviation (MD), glaucoma hemifield test (GHT), and VF index were used to develop sigmoidal regression models of CDR, analyzed for floor/ceiling effects of functional or structural damage by model comparisons based on logarithms of Bayes factors (logBF, with logBF > 5 indicating very strong evidence).

Results

We selected 17,509 eyes of 10,420 patients. For all outcomes, there was strong evidence for sigmoidal regression compared with linear regression (all logBF > 650). Model fits were characterized by plateauing for CDR toward 0, with ceilings for functional outcomes below the values denoting normal VFs (MD = 0 and VF index = 100). The clinician-estimated CDR was stronger associated with functional outcomes (all logBFs > 347) and optical coherence tomography-measured CDR with retinal nerve layer thickness (logBF = 243). Areas under the receiver operator characteristic curve for abnormal MD and GHT vs. CDR were 0.626 and 0.653, respectively. Optic disc diameter only marginally improved predictability (areas under the receiver operator characteristic curve increase for abnormal MD/GHT: 0.001/0.006).

Conclusions

CDR is subject to ceiling effects for glaucoma-related outcomes and poor at discriminating early glaucomatous damage. CDR values should be interpreted with care, particularly in screening settings.

Translational Relevance

This interpretable nonlinear model helps to better explain specific impacts on and limitations of CDR, one of the most frequently recorded parameters for glaucoma diagnostics.

Evaluation of Reproducibility of Measurements of Peripapillary Blood Flow with Laser Speckle Flowgraphy in Healthy and POAG Subjects

BACKGROUND

Peripapillary blood flow is of diagnostic value in glaucoma.

MATERIAL AND METHODS

We investigated the reproducibility of peripapillary blood flow measurements in healthy individuals and in open-angle glaucoma (OAG) patients with the Nidek laser speckle flowgraphy (LSFG)-NAVI system. Blood flow was calculated as the mean of vascular area (MV), mean of tissue area (MT), and mean of overall flow (MA). Intra-rater, inter-session, and inter-rater reproducibility were assessed by determining the intraclass correlation coefficient (ICC) and coefficient of variance (COV).

RESULTS

There were 28 healthy subjects and 16 patients with OAG who participated in this prospective single-center trial. ICC and COV of intra-rater reproducibility were assessed in MV as 0.901; 6.424, MT as 0.909; 4.025, and MA as 0.965; 4.168. Inter-session reproducibility yielded ICC and COV values of MV (0.834; 9.223), MT (0.904; 6.215), MA (0.909; 7.069). Inter-rater reproducibility was computed for MV as 0.78; 9.758, MT as 0.890; 7.210, and MA as 0.888; 6.942. There was a significant difference in MA (p = 0.0184) between the healthy individuals (mean 36.299) and the OAG group (mean 24.944), which was not observed for MV (p = 0.0735) or MT (p = 0.1351).

CONCLUSION

High reproducibility of measurements of peripapillary blood flow with the LSFG system was demonstrated in both groups. There is a difference in peripapillary blood flow between healthy controls and OAG patients.

Socioeconomic and environmental factors associated with glaucoma in an African Ancestry Population: findings from the Primary Open-Angle African American Glaucoma Genetics (POAAGG) study

BACKGROUND/OBJECTIVES

Glaucoma is the leading cause of irreversible blindness, disproportionately affecting individuals of African ancestry. Limited research has examined the impact of neighbourhood quality and socioeconomic factors on primary open-angle glaucoma (POAG) risk in this population. This study aims to address these gaps by evaluating associations between ocular health and neighbourhood characteristics using geospatial data.

SUBJECTS/METHODS

We conducted a case-control study with 5192 African ancestry individuals from the Philadelphia area using data from the Primary Open-Angle African American Glaucoma Genetics (POAAGG) study. Geocoded U.S. Census data were merged with individual-level demographics and neighbourhood-level measures, including air quality, food accessibility, and socioeconomic indicators, to assess their association with glaucoma risk and severity.

RESULTS

The study included 3039 controls (58.5%) and 2153 POAG cases (41.5%). Higher POAG risk was associated with older age (OR 1.72 per 10-year increase, p < 0.001), male gender (OR 2.04, p < 0.001), lower BMI (OR 0.87 per 10 kg/m2 increase, p = 0.003), and nonuse of alcohol (OR 0.56 for alcohol use, p < 0.001). Low food access was more common in controls (OR 0.86, p = 0.03), and severe POAG cases were associated with lower homeownership rates (OR 0.95 per 10% increase, p = 0.049). However, most socioeconomic and environmental factors (air quality, education, income, occupation, family structure) were not significantly linked to POAG risk or severity.

CONCLUSION

Socioeconomic status did not significantly protect against POAG in African ancestry individuals. Individual factors were more influential, suggesting neighbourhood and socioeconomic factors may have a lesser impact than previously hypothesised.

Revolution in glaucoma treatment: a review elucidating canaloplasty and gonioscopy-assisted transluminal trabeculotomy as modern surgical alternatives

Open-angle glaucoma (OAG) is a leading cause of permanent blindness worldwide, and surgical interventions that restore the natural aqueous humor outflow pathway have emerged as promising treatment options. Therefore, we aimed to analyze the efficacy and safety profile of specific antiglaucoma surgeries, namely canaloplasty (ab interno and ab externo techniques) and gonioscopy-assisted transluminal trabeculotomy (GATT), in surgical treatment patients with primary and secondary OAG. Consequently, a systematic review of the recent literature was conducted using online databases. The effectiveness of the surgeries was assessed by reductions in intraocular pressure (IOP) measurements and decreased use of antiglaucoma eye drops preoperatively and postoperatively. The safety profile of these procedures was evaluated by recording the incidence of specific intraoperative and postoperative complications. Independent studies have shown that ab interno and ab externo canaloplasty procedures and GATT effectively lower IOP and decline medications burden. Therefore, given the favorable safety profiles, canaloplasty and GATT are associated with low incidences of postoperative adverse events and exhibit comparable safety characteristics. However, additional research, including a well-conducted randomized controlled trial comparing ab externo and ab interno canaloplasty with GATT, is required to validate our findings.

Kahook Dual Blade Goniotomy Outcomes in the Underserved Dominican Republic Black and Afro-Latinx Population

Background/Objectives: Black and Afro-Latinx communities have a higher propensity for more-severe glaucoma at a younger age. This study aimed to use the Kahook Dual Blade (KDB) to treat all glaucoma subtypes and severity levels in this historically underserved community. Materials and Methods: This study involved a retrospective analysis of surgical case records, with follow-up through 20 months. The subjects were glaucoma patients at Hospital Elias Santana in Santo Domingo, Dominican Republic. Inclusion criteria were age >18 years and a minimum follow-up of 1 year after surgery. All glaucoma subtypes and disease severities were included, including previous glaucoma procedures. Sequential patients undergoing KDB goniotomy alone or in combination with phacoemulsification cataract surgery were assessed. IOP data and number of medications were collected at specific time points: baseline, postoperative day 1, postoperative week 1, and postoperative months 1, 3, 6, 12, 16, and 20. Surgical outcome was determined using IOP and number of medications. Success was defined as either a 20% or more reduction in IOP or a decrease in at least one topical therapy. Recorded postoperative complications were hyphema, ocular hypertension, and need for additional glaucoma surgery. Results: A total of 90 eyes from 90 patients were included. A total of 100% of the patient population was Black or Afro-Latinx. The most common glaucoma subtype was primary open-angle (76.7%). Most of the eyes had severe glaucoma (53.3%). The mean preoperative baseline IOP was 20.5 mmHg. The mean postoperative IOP from all time points ranged from 12.9 to 13.5 mmHg (all time points were significantly lower than baseline IOP, p < 0.0001). A mean reduction in IOP percent of at least 31.5% was seen at every time point. There was a mean reduction of two medications by postoperative month 20. Surgical success was achieved in 95.6% of patients at postoperative month 1 and remained high throughout the study period (95.4% at month 20). Conclusions: KDB goniotomy achieved successful IOP and medication reduction across all levels of glaucoma severity. Surgical success rates were maintained to 20 months. While MIGS has historically been used as an intervention in mild-to-moderate glaucoma, our study results show that the KDB can play a significant role in all stages of glaucoma, including severe. MIGS should be considered as a favorable intervention in all disease severities in Black and Afro-Latinx communities around the world.

Comparative insights into the role of sex hormones in glaucoma among women and men

Baseline differences in sex hormone levels between males and females influence tissues including the brain and eye. To investigate the effects of estrogens and androgens on ocular physiology and glaucoma, we review the current literature on the influence of primary sex hormones on ocular function, glaucoma incidence and related parameters like intraocular pressure (IOP) at physiologic levels and related to hormone therapies in men and women. These articles reveal activity of estrogen, testosterone, and progesterone within ocular tissues including the retinal pigment epithelium and ciliary epithelium where they likely influence glaucoma pathophysiology through effects on ocular blood flow and aqueous outflow. A growing body of evidence demonstrates a protective role of estrogen in glaucoma. With fluctuations across a woman's lifetime through menstrual phases, pregnancy, and menopause, the general association seen is a lower risk of glaucoma and lower IOP with higher estrogen. Exogenous hormones in the form of oral contraceptive pills and hormone replacement therapy also appear to affect glaucoma risk, although published findings are inconsistent. Few studies have reported a positive association between IOP and serum testosterone, and men treated with androgen deprivation therapy have shown a reduced risk of glaucoma while masculinizing hormone therapies at supra-physiologic testosterone levels have significantly increased IOP. Sex hormone perturbations affect components of glaucoma pathogenesis including IOP and ocular blood flow and overlap with known risk factors like age and sex. Standardized studies are needed to further elucidate the roles of estrogen and testosterone in glaucoma risk and progression.

Validating and Updating the OHTS-EGPS Model Predicting 5-year Glaucoma Risk among Ocular Hypertension Patients Using Electronic Records

OBJECTIVE

To validate and update the Ocular Hypertension Treatment Study-European Glaucoma Prevention Study (OHTS-EGPS) model predicting risk of conversion from ocular hypertension (OHT) to glaucoma using electronic medical records (EMR).

DESIGN

Evaluation and update of a risk prediction algorithm using EMRs and linked visual field (VF) tests.

PARTICIPANTS

Newly diagnosed OHT patients attending hospital glaucoma services in England. Inclusion criteria are as follows: intraocular pressure (IOP) 22 to 32 mmHg (either eye); normal baseline VF test, defined as Glaucoma Hemifield Test (GHT) "within normal range" in a reliable VF test; at least 2 VF tests in total; no significant ocular comorbidities.

METHODS

Risk factors are as follows: age, ethnicity, sex, IOP, vertical cup-to-disc ratio, central corneal thickness, VF pattern standard deviation, family history of glaucoma, systemic hypertension, diabetes mellitus, and glaucoma treatment. Glaucoma conversion was defined as 2 consecutive and reliable VF tests with GHT "outside normal limits" and/or need for glaucoma surgery. For validation, the OHTS-EGPS model was applied to predict a patient's risk of developing glaucoma in 5 years. In the updating stage, the OHTS model was refitted by re-estimating the baseline hazard and regression coefficients. The updated model was cross-validated and several variants were explored.

MAIN OUTCOME MEASURES

Measures of discriminative ability (c-index) and calibration (calibration slope) were calculated and pooled across hospitals using random effects meta-analysis.

RESULTS

From a total of 138 461 patients from 10 hospital glaucoma services in England, 9030 patients with OHT fitted the inclusion criteria. A total of 1530 (16.9%) patients converted to glaucoma during this follow-up period. The OHTS-EGPS model provided a pooled c-index of 0.61 (95% confidence interval: 0.60-0.63), ranging from 0.55 to 0.67 between hospitals. The pooled calibration slope was 0.45 (0.38-0.51), ranging from 0.25 to 0.64 among hospitals. The overall refitted model performed better than the OHTS-EGPS model, with a pooled c-index of 0.67 (0.65-0.69), ranging from 0.65 to 0.75 between hospitals.

CONCLUSIONS

We performed an external validation of the OHTS-EGPS model in a large English population. Refitting the model achieved modest improvements in performance. Given the poor performance of the OHTS-EGPS model in our population, one should use caution in its application to populations that differ from those in the OHTS and EGPS.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Clinical pearls from glaucoma clinical trials: a case-based approach

Purpose of review

The purpose of this review is to summarize past and present findings of established clinical trials in glaucoma with a case-based approach. We provide a general overview of each major trial and provide recommendations for their implementation in clinical practice.

Recent findings

Summary

There have been several large glaucoma clinical trials performed over the last three decades. These trials have guided clinical decision making by helping risk stratify patients and guide medical and surgical management.

Visual Field Progression in the Ocular Hypertension Treatment Study

PURPOSE

To determine the rate of visual field (VF) loss before and after the diagnosis of primary open angle glaucoma (POAG) in the Ocular Hypertension Treatment Study (OHTS).

DESIGN

Prespecified analyses of data collected prospectively in a clinical trial with extended follow-up.

SETTING AND PARTICIPANTS

Participants who developed POAG during OHTS 1 and 2 (February 1994 to December 2008) constitute an inception cohort. Follow-up data were collected in OHTS 3 (January 2016-April 2019). Analyses were performed from July 2021 to August 2022.

INTERVENTION

In OHTS 1 and 2, visual field (VF) tests were performed every 6 months and stereoscopic optic disc photographs were taken every 12 months. These tests were repeated in OHTS 3.

MAIN OUTCOMES AND MEASURES

Slopes of mean deviation (MD) were calculated by linear regression for all eyes in OHTS 1 and 2: eyes that did not develop POAG, eyes that developed optic disc POAG only, and eyes that developed VF POAG with/without optic disc POAG. Mean pre- and post-POAG slopes were calculated for eyes with a minimum of 5 VFs for each period.

RESULTS

Mean age at diagnosis of POAG was 66.4 ± 9.5 SD years (n = 282 participants), (56%) were male, 61% were White non-Hispanic and 32% were Black not Hispanic by self-report. The post-POAG slope was -0.40 ± 0.64 SD dB/year for all POAG eyes (n = 280 eyes), -0.19 ± 0.4 SD dB/yr. for optic disc POAG only eyes (n = 112 eyes), and -0.54 ± 0.7 SD dB/yr. for VF POAG eyes with or without optic disc POAG (n = 168 eyes). Among the VF POAG eyes, 69 (41%) had post-POAG MD slopes worse than or equal to -0.5 dB/year, 35 (21%) had slopes worse than or equal to -1.0 dB/year, and 9 (5.4%) had slopes worse than or equal to -2.0 dB/year.

CONCLUSIONS AND RELEVANCE

Some participants in OHTS had rapid rates of VF loss in one or both eyes despite being followed in a clinical study. This emphasizes that ocular hypertensive patients require careful follow-up, especially those at high risk of developing POAG to ensure early diagnosis and appropriate treatment of POAG.

Structural basis for anomalous cellular trafficking behavior of glaucoma-associated A427T mutant myocilin

Familial mutations in myocilin cause vision loss in glaucoma due to misfolding and a toxic gain of function in a senescent cell type in the anterior eye. Here we characterize the cellular behavior and structure of the myocilin (myocilin A427T) mutant, of uncertain pathogenicity. Our characterization of A427T demonstrates that even mutations that minimally perturb myocilin structure and stability can present challenges for protein quality control clearance pathways. Namely, when expressed in an inducible immortalized trabecular meshwork cell line, inhibition of the proteasome reroutes wild-type myocilin, but not myocilin A427T, from endoplasmic reticulum associated degradation to lysosomal degradation. Yet, the crystal structure of the A427T myocilin olfactomedin domain shows modest perturbations largely confined to the mutation site. The previously unappreciated range of mutant myocilin behavior correlating with variable stability and structure provides a rationale for why it is challenging to predict causal pathogenicity of a given myocilin mutation, even in the presence of clinical data for members of an affected family. Comprehending the continuum of mutant myocilin behavior in the laboratory supports emerging efforts to use genetics to assess glaucoma risk in the clinic. In addition, the study supports a therapeutic strategy aimed at enhancing autophagic clearance of mutant myocilin.

Assessment of anterior scleral thickness in Turkish open angle glaucoma patients: an anterior segment optical coherence tomography study

BACKGROUND

To compare anterior scleral thickness (AST) in Turkish patients with open-angle glaucoma (primary open-angle glaucoma (POAG) and pseudoexfoliation glaucoma (PEG)) with healthy controls.

METHODS

This prospective study involved 41 patients with PEG, 69 patients with POAG, and 46 healthy controls. We obtained spectral domain anterior segment optical coherence tomography (AS-OCT) images from the nasal and temporal quadrants and made AST measurements of 1 mm (AST), 2 mm (AST2), 3 mm (AST3), and 4 mm (AST4) posterior to the scleral spur (SS). Schlemm's canal (SC) diameter and area measurements were performed using the ImageJ software. The results were compared statistically.

RESULTS

The average ASTs of the groups did not differ significantly (p > 0.05 for each). The analysis of the nasal SC diameter revealed a significant decrease in the POAG group in comparison with the PEG group, with no difference observed between the POAG and control groups (p = 0.038*). The mean nasal and temporal SC area was significantly smaller in the PEG and POAG groups compared with the control group (p < 0.001** and p < 0.001**, respectively).

CONCLUSIONS

There was no significant difference in nasal and temporal AST between groups; however, the SC area was found to be smaller in glaucoma groups compared with healthy controls. The present findings should be supported by further studies.

Comparing the Effectiveness of Propensity Score-Matched Ab Interno Trabeculotomy Between Two Types of Trabecular Hooks

Purpose

This retrospective study compares the surgical outcomes of ab interno trabeculotomy using the Kahook Dual Blade (KDB) and Tanito microhook (TMH) combined with cataract surgery.

Patients and Methods

Twenty-four eyes from 19 and 17 patients with glaucoma in the KDB and TMH groups, respectively, were included. Background factors were matched for medication score and disease type using propensity scores.

Results

Preoperative age, sex, intraocular pressure (IOP), medication scores, and disease type were comparable between the groups. The intraoperative incision range was lower in the KDB than TMH group. The postoperative medication scores and IOPs were 2.7±1.6 mmHg and 14.5 ± 2.8 mmHg in the KDB group, and 2.0±1.8 and 13.8 ± 3.4 mmHg in the TMH group, respectively. There were no significant differences between the groups regarding changes in medication scores, IOP reduction rate, or survival 6 months postoperatively. Postoperative IOP changes were significantly associated with preoperative IOP in both groups, and trabeculotomy range in the KDB group. There were no significant between-group differences regarding the incidence of postoperative complications, excluding a higher incidence of hyphema in the TMH group.

Conclusion

Surgical outcomes for ab interno trabeculotomy using the KDB and TMH were not significantly different. There was no significant difference in the occurrence of postoperative complications, except hyphema, which may reflect the difference in the incision range of trabeculotomy between the hooks. Finally, in the KDB group, where narrow incisions range up to just over one quadrant, the trabeculotomy incision range correlated with IOP.

Baseline choroidal microvasculature dropout as a predictor of rapid global structural loss in open-angle glaucoma

This study included 102 open-angle glaucoma (OAG) eyes with or without a localized choroidal microvasculature dropout (CMvD) at the inferior hemiretina, matched for age (≤ 10 years), axial length (≤ 1 mm), and visual field severity (≤ 1dB), and with a minimum 2-year follow-up. Serial thickness [circumpapillary retinal nerve fiber layer (cpRNFLT) and macular ganglion cell-inner plexiform layer thickness (mGCIPLT)], and vessel density (VD) [circumpapillary (cpVD) and macular VD (mVD)] parameters were obtained. The rate of change in each parameter at both the superior (CMvD-unaffected) and inferior (CMvD-affected) hemiretina were compared between matched eyes with (CMvD+) and without CMvD (CMvD-). Clinical factors associated with the rate of change in each parameter both globally and at the CMvD-unaffected hemiretina were also evaluated. CMvD + eyes showed significantly faster rates of VD and thickness loss at both the CMvD-affected and -unaffected hemiretina. In addition, CMvD was significantly associated with rapid loss of both VD and thickness parameters globally and at the CMvD-unaffected superior hemiretina. In conclusion, OAG eyes with CMvD show significantly faster rates of VD and thickness loss at both the CMvD-affected and unaffected hemiretina. A localized CMvD is an independent predictor of globally rapid structural loss in OAG eyes.

Central Corneal Thickness and Glaucoma Risk: The Importance of Corneal Pachymetry in Screening Adults Over 50 and Glaucoma Suspects

Glaucoma is a leading cause of preventable blindness, yet nearly half of those affected are unaware of their diagnosis. Individuals with glaucoma may present with "normal" or "lower" intraocular pressure (IOP) compared to typical glaucoma thresholds, due in large part to many of these individuals having thin corneas. Conversely, many with elevated IOP and thicker corneas may not necessarily have glaucoma. In this article, we review the importance of central corneal thickness (CCT) and corneal pachymetry devices in eye care. Additionally, we review the role of corneal thickness as a risk factor for glaucoma and glaucoma progression. PubMed and Web of Science databases were searched for articles and reviews on corneal pachymetry and its use in glaucoma, corneal biomechanics and refractive surgery, and glaucoma screening. The results of this review revealed that CCT is a risk factor for development of glaucoma, and in eyes suspected of glaucoma, corneal pachymetry can be performed by trained technicians to provide important information related to the risk of acquiring glaucoma and/or having other ocular diseases. Additionally, a lower CCT is associated with an increased risk of progression and faster rates of visual field loss in eyes with glaucoma. This review will provide evidence regarding the importance of performing corneal pachymetry on all persons over the age of 50 as part of a comprehensive eye examination to better identify those patients who have glaucoma or are glaucoma suspects.

Outcomes of Glaucoma Referrals in Adults Aged 18 to 40 Years

Importance

While early detection of glaucoma is vital to prevent irreversible vision loss, there are sparse data on the effectiveness of glaucoma referrals and methods to establish evidence-based referral guidelines in large, diverse populations.

Objective

To assess the prevalence and risk factors for diagnosed glaucoma and loss to follow-up among adult patients aged 18 to 40 years after a new diagnosis of referable glaucoma (ie, with glaucoma or suspected glaucoma).

Design, Setting, and Participants

This retrospective cohort study included patients aged 18 to 40 years presenting to Kaiser Permanente Southern California, a large managed health care system, for first-time eye examinations between January 1, 2013, and December 31, 2018. Data analysis occurred between September 2022 and August 2024.

Main Outcomes and Measures

The primary outcome was glaucoma diagnosed within 2 years of the first eye examination. The secondary outcome was the loss to follow-up, defined as failure to receive a glaucoma evaluation with visual field or optical coherence tomography testing within 2 years.

Results

The cohort included 292 453 patients aged 18 to 40 years who underwent first-time eye evaluations (mean [SD] age, 29.8 [6.4] years). Among 12 050 identified patients with referable glaucoma (52.3% female), 6827 (56.7%) completed glaucoma evaluations, of whom 563 (8.2%) were diagnosed with glaucoma (344 [61.1%] with open angle, 28 [5.0%] with angle closure, 84 [14.9%] with secondary glaucoma, and 107 [19.0%] with unspecified glaucoma). On multivariable analysis, male sex (odds ratio [OR], 1.55 [95% CI, 1.07-2.27]), higher intraocular pressure (IOP) (OR, 1.19 [95% CI, 1.15-1.23] per 1 mm Hg), and greater cup-disc ratio (CDR) (OR, 1.53 [95% CI, 1.34-1.75] per 0.1 unit) were associated with greater odds of glaucoma. Dichotomized age, IOP, and CDR models stratified 51 of 1613 patients (3.2%) into the low-risk group and 202 of 1477 patients (13.7%) into the high-risk group. Being younger than 32 years and having an IOP less than 18 mm Hg and a CDR less than 0.7 yielded a negative predictive value of 98.2% for a glaucoma diagnosis.

Conclusions and Relevance

In this cohort study, the diagnostic yield of glaucoma referrals was low among adults aged 18 to 40 years with first-time eye examinations. A simple risk-stratification strategy could help identify individuals with low and high risks of developing glaucoma, and adoption of evidence-based risk stratification and referral guidelines by health care systems and clinicians could improve equity of glaucoma care and use of eye-care resources.

Glaucoma Disease-Specific Adherence Measurement Tools Validated for Measuring Adherence to Glaucoma Medications: A Systematic Review

Background

Reviewing validated glaucoma disease-specific tools for measuring adherence could encourage adherence monitoring to avoid progressive visual field losses in people living with glaucoma.

Aim

To review the literature on validated disease-specific tools for measuring adherence to glaucoma medications.

Methods

Relevant peer-reviewed publications from the year 2000 to 2022 from PubMed, EMBASE, Scopus, and PROquest were retrieved. For each search conducted, the name of the search engine used, date of search, number of publications retrieved, and keywords used were documented. The selected articles were reviewed for inclusion and assessed for biases and quality. Each tool was described by the type of measurement, technique for measurement, strengths and weaknesses, and method of validation, respectively.

Results

Out of the 10 included articles, seven glaucoma disease-specific tools were identified namely; Glaucoma Treatment Compliance Assessment Tool-Short form (GTCAT-S), Glaucoma Treatment Compliance Assessment Tool-Long form (GTCAT-L), Travatan Dosing Aid (TDA), Eye-Drop Satisfaction Questionnaire (EDSQ), Glaucoma Adherence Questionnaire-Revised (GAQ-R), Glaucoma Adherence Questionnaire-Old (GAQ-O), and Schwartz Adherence Questionnaire (SAQ). Three studies had a low risk of bias, and seven recorded a moderate risk of bias. The TDA, GTCAT-S, and GTCAT-L were rated as high-quality tools.

Conclusions

Seven glaucoma disease-specific tools for measuring adherence were found. Integration of regular measurement of medication adherence as part of care for glaucoma patients would be beneficial for both patients and providers of eye care.

Diagnostic Decision-Making Variability Between Novice and Expert Optometrists for Glaucoma: Comparative Analysis to Inform AI System Design

BACKGROUND

While expert optometrists tend to rely on a deep understanding of the disease and intuitive pattern recognition, those with less experience may depend more on extensive data, comparisons, and external guidance. Understanding these variations is important for developing artificial intelligence (AI) systems that can effectively support optometrists with varying degrees of experience and minimize decision inconsistencies.

OBJECTIVE

The main objective of this study is to identify and analyze the variations in diagnostic decision-making approaches between novice and expert optometrists. By understanding these variations, we aim to provide guidelines for the development of AI systems that can support optometrists with varying levels of expertise. These guidelines will assist in developing AI systems for glaucoma diagnosis, ultimately enhancing the diagnostic accuracy of optometrists and minimizing inconsistencies in their decisions.

METHODS

We conducted in-depth interviews with 14 optometrists using within-subject design, including both novices and experts, focusing on their approaches to glaucoma diagnosis. The responses were coded and analyzed using a mixed method approach incorporating both qualitative and quantitative analysis. Statistical tests such as Mann-Whitney U and chi-square tests were used to find significance in intergroup variations. These findings were further supported by themes extracted through qualitative analysis, which helped to identify decision-making patterns and understand variations in their approaches.

RESULTS

Both groups showed lower concordance rates with clinical diagnosis, with experts showing almost double (7/35, 20%) concordance rates with limited data in comparison to novices (7/69, 10%), highlighting the impact of experience and data availability on clinical judgment; this rate increased to nearly 40% for both groups (experts: 5/12, 42% and novices: 8/21, 42%) when they had access to complete historical data of the patient. We also found statistically significant intergroup differences between the first visits and subsequent visits with a P value of less than .05 on the Mann-Whitney U test in many assessments. Furthermore, approaches to the exam assessment and decision differed significantly: experts emphasized comprehensive risk assessments and progression analysis, demonstrating cognitive efficiency and intuitive decision-making, while novices relied more on structured, analytical methods and external references. Additionally, significant variations in patient follow-up times were observed, with a P value of <.001 on the chi-square test, showing a stronger influence of experience on follow-up time decisions.

CONCLUSIONS

The study highlights significant variations in the decision-making process of novice and expert optometrists in glaucoma diagnosis, with experience playing a key role in accuracy, approach, and management. These findings demonstrate the critical need for AI systems tailored to varying levels of expertise. They also provide insights for the future design of AI systems aimed at enhancing the diagnostic accuracy of optometrists and consistency across different expertise levels, ultimately improving patient outcomes in optometric practice.

Resident Tissue Macrophages Govern Intraocular Pressure Homeostasis

Intraocular pressure is tightly regulated by the conventional outflow tissues, preventing ocular hypertension that leads to neurodegeneration of the optic nerve, or glaucoma. Although macrophages reside throughout the conventional outflow tract, their role in regulating intraocular pressure remains unknown. Using macrophage lineage tracing approaches, we uncovered a dual macrophage ontogeny with distinct spatial organizations across the mouse lifespan. Long-lived, resident tissue macrophages concentrated in the trabecular meshwork and Schlemm's canal, whereas short-lived monocyte-derived macrophages, instead, were abundant around distal vessels. Specific depletion of resident tissue macrophages triggered elevated intraocular pressure and outflow resistance, linked to aberrant extracellular matrix turnover in the resistance-generating tissues of the trabecular meshwork. This dysregulated physiology and tissue remodeling were not observed when we depleted monocyte-derived macrophages. Results show ontogeny and tissue-specific macrophage function within the outflow tract, uncovering the integral homeostatic role of resident tissue macrophages in resistance-generating tissues whose dysfunction is responsible for glaucoma.

Structural and vascular assessment of the optic nerve head and macula in chronic Chagas disease

Chagas disease (CD), a parasitic infection, may have ocular repercussions in its cardiologic form, since a history of heart disease of other etiologies already has been established as a risk factor for neuropathies and maculopathies. The aim of the present study was to investigate preclinical structural and vascular optic nerve head (ONH) and macular parameters in patients with chronic CD. Nineteen patients with CD and 19 healthy subjects were evaluated with optical coherence tomography, optical coherence tomography angiography, and Laguna ONhE® software. The main outcome measures were the glaucoma discriminant factor, average peripapillary retinal nerve fiber layer thickness, macular ganglion cell complex thickness, peripapillary vascular density (VD), foveal and parafoveal thickness, foveal avascular zone area, and total foveal and parafoveal VD from the superficial and deep capillary plexus that were compared between the two groups. No significant differences were observed among the studied variables. Although our findings suggested that the cardiovascular dysfunction resulting from chronic CD does not seem to cause significant structural or vascular preclinical changes to the ONH and the macula, the results herein benefit this patient population and may provide important preliminary information about the ocular impairment caused by the condition and its possible systemic complications.

Association between age at diagnosis of diabetes and ocular disease: Insights from a recent article

In this article, we discuss Ye et al's recent article on the association between age at diabetes diagnosis and subsequent risk of age-related ocular diseases. The study, which utilized United Kingdom Biobank data, highlighted a strong link between early diabetes onset and major eye conditions, such as cataracts, glaucoma, age-related macular degeneration, and vision loss, independent of glycemic control and disease duration. This finding challenges the previous belief that diabetic eye disease primarily correlates with hyperglycemia. As lifestyles evolve and the age of diabetes diagnosis decreases, understanding this relationship may reveal the complex pathogenesis underlying diabetes-related complications. This editorial summarizes potential mechanisms connecting the age of diabetes onset with four types of ocular diseases, emphasizing the significance of early diagnosis.

"Intrableb pigmentation following XEN implantation: A case series"

PURPOSE

To evaluate the incidence and to describe the characteristics of the intrableb pigmentation (IBP) following XEN63 implantation.

METHODS

Retrospective case series of three eyes presenting a pigment dispersion in the filtering bleb after a XEN63 implantation for uncontrolled IOP. Demographic, clinical and imaging data were obtained from medical records.

RESULTS

Three out of 40 patients who underwent XEN implantation (average age 70.67 years) showed an IBP during the 12 months postoperative period. The mean time of IBP onset was 50 days (range, 15-90). The slit lamp examination showed two IBP patterns: a "diffuse" pattern (2 patients) with multiple spots of pigmentation inside the bleb; a "punctiform" pattern (1 patient), with a single spot at the distal end of the device. The AS-OCT imaging confirmed the presence of IBP appearing as a hyperreflective spot/s in the context of the filtering bleb. The patient with the punctiform IBP experienced a distal XEN ostium obstruction with a decrease in bleb function. In one case the diffuse IBP occurred after a successful needling procedure. All the patients' IOP reported at the end of the follow-up was below 21 mmHg.

CONCLUSION

The development of IBP might occur after XEN implantation in various times and with different patterns. The IBP pattern can provide meaningful clues on the bleb filtering function. A proper follow-up based on slit lamp biomicroscopy, IOP measurement, and AS-OCT imaging is recommended to manage potential complications related to IBP.

Performance of Polygenic Risk Scores for Primary Open-Angle Glaucoma in Populations of African Descent

Importance

Primary open-angle glaucoma (POAG) polygenic risk scores (PRSs) continue to be evaluated in primarily European-ancestry populations despite higher prevalence and worse outcomes in African-ancestry populations.

Objective

To evaluate how established POAG PRSs perform in African-ancestry samples from the Genetics in Glaucoma Patients of African Descent (GIGA), Genetics of Glaucoma in Individuals of African Descent (GGLAD), and Million Veteran Program (MVP) datasets and compare these with European-ancestry samples.

Design, Setting, and Participants

This was a multicenter, cross-sectional study of POAG cases and controls from Tanzania, South Africa, Nigeria, Ghana, and the US. Included were individuals of African descent from South Africa and Tanzania from the GIGA dataset; individuals of African descent from Ghana, Nigeria, and the US from the GGLAD dataset; and individuals of African or European descent from the US in the MVP dataset. Data were analyzed from January 2022 to July 2023.

Exposures

Three PRSs derived from large meta-analyses of European and Asian populations, namely Gharahkhani et al (Gharahkhani PRS), Han et al (Han PRS), and Craig et al (Craig PRS).

Main Outcomes and Measures

Odds ratios (ORs) for POAG risk stratification comparing the highest and lowest quintiles; area under the receiver operating characteristic curve (AUROC), and liability coefficient of determination (R2) for the addition of PRS to a baseline of age, sex, and first 5 principal components.

Results

A total of 11 673 cases and 66 432 controls were included in this study across 7 ancestral groups. Mean (SD) age of the total participants was 76.9 (8.7) years, with 74 304 males (95.1%). The following were included in each dataset: GIGA (663 cases, 476 controls), GGLAD (1471 cases, 1482 controls), and MVP (9559 cases, 64 474 controls). Increases in ORs were found for the highest POAG risk quintile ranging from an OR of 1.68 (95% CI, 1.17-2.43) in Ghanaians to 7.05 (95% CI, 2.73-19.6) in the South African multiple ancestry group (which derives from at least 5 distinct ancestral groups: Khoisan, Bantus, Europeans, Indians, and Southeast Asians) with the Gharahkhani PRS. The Han PRS showed OR increases for the highest POAG risk quintile ranging from 2.27 (95% CI, 1.49-3.47) in African American individuals in the GGLAD dataset to 7.24 (95% CI, 6.47-8.12) in Europeans. The Craig PRS predicted OR increases in the highest quintile for all groups ranging from 1.51 (95% CI, 1.05-2.18) in Ghanaians to 6.31 (95% CI, 5.67-7.04) in Europeans. However, AUROC and R2 increases above baseline were lower for all African-ancestry compared with European-ancestry groups in the 3 tested PRSs.

Conclusions and Relevance

In this cross-sectional study, despite some improvements in OR-based risk stratification using the Gharahkhani PRSs, Han PRSs, and Craig PRSs, consistently lower improvements in AUROC and R2 for African-ancestry compared with European-ancestry groups highlight the need for risk prediction models tailored to diverse populations.

Immediate Effects of Goldmann Applanation Tonometry on Central Corneal Thickness Measurements Using Contact and Non-contact Pachymetry Methods

PURPOSE

The objective was to evaluate the immediate impact of Goldmann Applanation Tonometry (GAT), a gold-standard intraocular pressure measurement technique, on the reliability of central corneal thickness (CCT) measurements and to compare the outcomes between contact and non-contact pachymetry methods.

METHODS

Fifty-one adult participants without ocular pathology were enrolled. Serial CCT measurements were conducted using three different pachymetry modalities across three days, both at baseline and post-GAT: Day 1 with an ultrasound pachymeter (USP), Day 2 using optical low-coherence reflectometry (OLCR), and Day 3 via anterior segment optical coherence tomography (AS-OCT). The study involved comparing mean CCT and CCT standard deviation at baseline and post-GAT using one-way analysis of variance (ANOVA) and paired t-tests.

RESULTS

In the 610 CCT measurements performed, mean CCT did not show significant changes post-GAT overall or by modality (USP: +2.20 microns, p=0.63; OLCR: +1.0 microns, p=0.93; AS-OCT: +0.40 microns, p=0.95). However, contact USP consistently produced thicker corneal readings than non-contact OLCR and AS-OCT both at baseline and post-GAT (p < 0.0001). Notably, there was a significant increase in CCT standard deviation (+51.1%) and a decrease in adherence to technical repeatability specifications with contact USP following GAT (from 55% to 33%, p < 0.05).

CONCLUSIONS

The study suggests that contact intraocular pressure measurement methods like GAT may influence the reliability and repeatability of CCT measurements, as observed in our increased CCT measurement standard deviations. This could have important implications for accurate diagnosis and treatment planning for various ocular conditions. Given the study's limited sample size, further research may be warranted.

Effects of trabeculectomy on the postoperative central visual field as revealed by refraction values

PURPOSE

To evaluate the effects of trabeculectomy on the rate of deterioration of the central visual field (VF) in patients with normal-tension glaucoma (NTG), as revealed by refraction values.

STUDY DESIGN

Retrospective case series.

METHODS

We retrospectively analyzed 28 eyes, including 12 high myopic (spherical equivalent [SE] < - 6 diopters without pathological myopia) and 16 non-high myopic (SE ≥ - 6 diopters) eyes. The rate of VF deterioration (dB/year) was determined using linear regression analysis of 30 -2 and 10 -2 VF tests. The Wilcoxon signed-rank test was used to compare deterioration rates between groups. To assess the influence of initial post-surgery effects, statistical analyses were conducted with and without data from the initial postoperative VF exam.

RESULTS

Trabeculectomy significantly reduced intraocular pressure (IOP) in myopic (14.1 to 9.0 mmHg, P ≤ 0.01) and non-myopic (13.4 to 9.5 mmHg, P ≤ 0.01) eyes. Postoperatively, the 10-2 VF deterioration rate significantly decreased in myopic (- 1.31 to - 0.55 dB/year, P = 0.01) and non-myopic (- 0.80 to - 0.30 dB/year, P = 0.03) eyes. Excluding the first postoperative VF exam, the deterioration rates were - 0.51 ± 0.24 dB/year and - 0.54 ± 0.89 dB/year, respectively, indicating a minor impact on progression assessment.

CONCLUSIONS

Trabeculectomy may mitigate central VF deterioration in myopic NTG patients, emphasizing the potential benefits of timely surgical intervention. Further studies are needed to determine the optimal timing for surgery.

The need for more pragmatic trials in glaucoma research

AIM

There have been a number of clinical trials in glaucoma research published in the past two decades. Most of these trials were designed to evaluate very specific issues in selected populations placing them in the explanatory end of the pragmatic-explanatory continuum. The purpose of this study was to assess the level of pragmatism of published randomized controlled trials in glaucoma.

METHODS

A PubMed search using 'glaucoma' from 1995 to 2022 and randomized controlled trial (RCT) article type was done. Each study was assessed by three independent examiners using the Pragmatic-Explanatory Continuum Indicator Summary version 2 (PRECIS-2) toolkit. Scores were calculated for each study to determine the level of pragmatism. A summed score ≥36 was indicative of a very pragmatic study.

RESULTS

Thirty-two different articles were included in the analysis. These papers represented 13 different landmark trials. The median PRECIS-2 score was 32 (range, 25 for the Early Manifest Glaucoma Trial (EMGT) to 34 to the Collaborative Normal Tension Glaucoma Study (CNTGS) and the Ocular Hypertension Treatment Study). The Treatment of Advanced Glaucoma Study (TAGS), was considered very pragmatic and scored 33 points.

CONCLUSION

Despite the number of RCTs in glaucoma, there is still a need for more pragmatic studies.

Association between metformin use with circumpapillary retinal nerve fibre layer thickness and capillary vessel density in glaucoma

BACKGROUND/AIMS

To investigate the association between use of metformin and circumpapillary retinal nerve fibre layer (cpRNFL) thickness, as well as whole image capillary density (wiCD), in patients with glaucoma.

METHODS

This cross-sectional study included patients with glaucoma suspect or primary open-angle glaucoma (POAG) underwent optical coherence tomography angiography imaging. Use and duration of antidiabetic medications were assessed at the time of imaging. Multivariable linear mixed-effect modelling was used to estimate the effect of diabetes medication on wiCD and cpRNFL while controlling for covariates including age, race, body mass index, diagnosis, 24-2 visual field mean deviation, and intraocular pressure, average signal strength index as well as any variables that showed a p <0.1 in the univariable analysis.

RESULTS

A total of 577 eyes (330 POAG and 247 glaucoma suspect) of 346 patients were included. Sixty-five patients (23%) had diabetes, of whom 55 (78.5%) used metformin, and 17 (26.2%) used insulin. After adjusting for covariates, the association between metformin use and wiCD (1.56 (95% CI 0.40 to 2.71); p=0.008), duration of metformin use and wiCD (0.12 (95% CI 0.02 to 0.22) per 1 year longer; p=0.037), and metformin use and cpRNFL thickness (5.17 (95% CI 1.24 to 9.10) µm; p=0.010) had statistically significant associations in each model.

CONCLUSIONS

Metformin use was associated with higher wiCD and thicker cpRNFL. These findings indicate a potential association, underscoring the need for longitudinal studies to determine if metformin plays a role in the retinal conditions of patients with glaucoma.

TRIAL REGISTRATION NUMBER

NCT00221897.

Central corneal thickness and the risk of primary open-angle glaucoma: a Mendelian randomisation mediation analysis

BACKGROUND

The association of central corneal thickness (CCT) with primary open-angle glaucoma (POAG) remains uncertain. Although several observational studies assessing this relationship have reported an inverse association between CCT and POAG, this could be the result of collider bias. In this study, we leveraged human genetic data to assess through Mendelian randomisation (MR) the effect of CCT on POAG risk and whether this effect is mediated by intraocular pressure (IOP) changes.

METHODS

We used 24 single-nucleotide polymorphisms (SNPs) associated with CCT (p value<5×10-8) from a genome-wide association study (GWAS) (N=17 803) provided by the International Glaucoma Genetics Consortium and 53 SNPs associated with IOP (p value<5×10-8) from a GWAS of the UK Biobank (UKBB) (N=97 653). We related these instruments to POAG using a GWAS meta-analysis of 8283 POAG cases and 753 827 controls from UKBB and FinnGen.

RESULTS

MR analysis suggested a positive association between CCT and POAG (OR of POAG per 50 µm increase in CCT: 1.38; 95% CI: 1.18 to 1.61; p value<0.01). MR mediation analysis showed that 28.4% of the total effect of CCT on POAG risk was mediated through changes in IOP. The primary results were consistent with estimates of pleiotropy-robust MR methods.

CONCLUSION

Contrary to most observational studies, our results showed that a higher CCT is associated with an increased risk of POAG.

Study of the impact of the vascular systemic risk factors on peripapillary vascular density by optical coherence tomography angiography

BACKGROUND

The focus of therapeutic tools in glaucoma has been mainly to control of intraocular pressure. Recently there has been a growing interest in investigating the relationship of vascular risk factors in the development of glaucoma. The aim of this study was to assess the association between systemic arterial hypertension, diabetes mellitus and hypercholesterolemia, and peripapillary vascularization measured by Optical Coherence Tomography Angiography (OCTA) in glaucoma and healthy subjects.

METHODS

In this unicenter, observational, cross-sectional study, 212 subjects, 118 glaucoma patients and 94 controls were consecutively recruited. Of these, 86 participants were excluded due to poor OCTA image quality. Therefore, 146 subjects were included in the final analysis, 74 glaucoma patients and 72 controls. Using a linear regression model, with 95% confidence and 80% statistical power, the effect of vascular risk factors on OCTA parameters in the 146 subjects included in the final analysis was studied.

RESULTS

No significant impact of vascular risk factors on OCTA measurements was found. Diabetic patients tended to show a lower peripapillary perfusion vascular density than subjects without diabetes (β 0.016, 95%CI 0.003;0.030, p 0.016). Similarly, hypercholesterolemia patients appeared to show less peripapillary flow index than non-hypercholesterolaemic patients (β 0.029, 95%CI 0.013;0.046, p 0.001). Glaucoma patients had 0.02% lower peripapillary perfusion vascular density (β 0.020, 95% CI 0.011;0.029, p < 0.001), 0.04% lower peripapillary flow index (β 0.036, 95%CI 0.022;0.051, p < 0.001) and 9.62% thinner retinal nerve fibre layer (β 9.619, 95%CI 5.495;13.744, p < 0.001).

CONCLUSIONS

In conclusion glaucoma has greater effect on peripapillary vascular density parameters than any of the vascular risk factors analyzed.

KEY MESSAGES

What is known: • Vascular disfunction plays an important role in the development of glaucoma. • Optical coherence tomography angiography makes it possible to assess the retinal microvasculature and the role that its alterations could have in the development of glaucoma.

WHAT IS NEW

• Decrease of the peripapillary microcirculation seems to be more related to the increase in intraocular pressure and the glaucoma itself than to the presence of cardiovascular risk factors. • The effect of having diabetes, systemic arterial hypertension or hypercholesterolaemia on vascular parameters or nerve fibre layer thickness was low. • There was also no relevant impact of the systemic medication used for these diseases on the peripapillary vascular parameters studied or on nerve fibre layer thickness.

Corneal Confocal and Specular Microscopic Characteristics in Primary Open-Angle Glaucoma: An Optical Coherence Tomography (OCT)-Based Case-Control Study

BACKGROUND

Glaucoma, particularly open-angle glaucoma (OAG), is a leading cause of irreversible blindness, associated with optic nerve damage, retinal ganglion cell death, and visual field defects. Corneal biomechanical properties and cellular components, such as corneal nerve and keratocyte densities assessed by in vivo confocal microscopy (IVCM), may serve as biomarkers for glaucoma progression. This study aimed to explore the relationship between corneal nerve parameters, keratocyte density, and optical coherence tomography (OCT)-derived retinal nerve fiber layer (RNFL) thickness in primary open-angle glaucoma (POAG) patients and controls.

METHODS

This case-control study was conducted at Al-Shifa Trust Eye Hospital, Rawalpindi, Pakistan, from January 2023 to October 2024. It included 26 eyes of 17 glaucoma patients and 28 eyes of 18 age-matched controls. POAG was diagnosed based on elevated intraocular pressure (IOP), optic disc changes, RNFL defects, and visual field abnormalities. Participants underwent full ophthalmic evaluation, including OCT for RNFL thickness, specular microscopy, and corneal confocal microscopy (CCM). Data were analyzed using IBM SPSS Statistics for Windows, Version 26.0 (Released 2019; IBM Corp., Armonk, New York, United States), with Spearman's correlation and linear regression for association analysis.

RESULTS

Anterior stromal keratocyte density was significantly lower in glaucoma patients (436.63±145.44 cells/mm²) compared to controls (546.54±141.20 cells/mm²; p=0.007). No significant difference was found in posterior stromal keratocyte density (p=0.788). Corneal nerve parameters showed a higher nerve fiber length in glaucoma patients (19.25±5.74 mm/mm²), but the difference was not significant (p=0.143). Nerve branch density was significantly higher in glaucoma patients (40.22±23.44 branches/mm²) compared to controls (26.12±10.17 branches/mm²; p=0.054). Specular microscopy revealed significantly lower endothelial cell density in glaucoma patients (2159.8±393.39 cells/mm²) compared to controls (2474.15±272.59 cells/mm²; p=0.002). OCT measurements showed a significantly thinner global RNFL in glaucoma patients (69.79±24.79 µm) compared to controls (98.86±9.04 µm; p<0.001). Spearman's correlation analysis showed that anterior keratocyte density was positively correlated with global (r=0.294; p=0.045), superior (r=0.312; p=0.031), and inferior quadrant RNFL thickness (r=0.285; p=0.049). It was also negatively correlated with central corneal thickness (CCT) (r=-0.367; p=0.039). In multivariate analysis, the duration of glaucoma was significantly associated with RNFL thickness (p=0.011).

CONCLUSION

This study found that anterior stromal keratocyte density was positively correlated with RNFL thickness, suggesting a potential link between corneal cellular changes and glaucoma severity. Endothelial cell density was significantly lower in glaucoma patients, which may reflect the disease's impact or the effect of medications on corneal health. While corneal nerve parameters did not show significant differences, these findings highlight the importance of corneal biomechanical properties in glaucoma pathophysiology. Further studies with larger sample sizes and longer follow-up periods are needed to confirm these findings and explore the role of corneal parameters in glaucoma progression.

Amniotic membrane graft to patch an overfiltering trabeculectomy flap

Purpose

To describe the use of an amniotic membrane graft (AMG) with fibrin sealant to address an overfiltering trabeculectomy flap encountered intraoperatively.

Observations

A 35-year-old female with severe primary open angle glaucoma underwent trabeculectomy with mitomycin C due to uncontrolled intraocular pressure (IOP). Intraoperatively, the elastic nature of the scleral flap led to overfiltration, causing persistent anterior chamber shallowing despite numerous sutures. To decrease but not completely shut down aqueous outflow through the trabeculectomy flap, we utilized AMG and fibrin sealant to stabilize the flap. Postoperatively, the patient had a formed anterior chamber, elevated bleb and significantly reduced IOP, without the need for additional glaucoma medications.

Conclusions and importance

Amniotic membrane grafts (AMG) with fibrin sealant may help regulate aqueous flow efflux, maintain anterior chamber stability, and mitigate the risk of postoperative hypotony in trabeculectomy surgery. AMG was chosen in this setting given its anti-inflammatory, anti-fibrotic properties, as well as its optically clear nature to allow for post-operative visualization of the flap. AMG allows for early postoperative stabilization of the scleral flap without complete obstruction, and may be useful in patients at risk of early postoperative hypotony.

Reproducibility of the Time of Intraocular Pressure Peaks During Water-drinking Test in Patients Treated for Open-angle Glaucoma

Purpose

To evaluate the reproducibility and intra-eye similarity of the intraocular pressure (IOP) peaks induced by the water drinking test (WDT) in treated glaucoma patients.

Methods

This prospective cohort study evaluated 99 patients (198 eyes) who were treated for primary open-angle glaucoma. All patients underwent WDT in two consecutive visits with no change in their current therapy. The interval between the tests was 4 four to six months. The tests were administered at a similar time (4:00 PM ± 1 hour). The reproducibility of the time of the IOP peaks and the correlation between the peak time of both eyes during the two consecutive WDT sessions were assessed.

Results

Of all IOP peaks, 59.6% and 71.7% occurred at the same time during the two WDT sessions in the right and left eyes, respectively. In the first and second WDT sessions, the agreements in IOP peak time between the right and left eyes were 60% and 63%, respectively.

Conclusion

The IOP peak time between the two consecutive WDT sessions was moderately reproducible, and there was a moderate agreement in the peak time between the two eyes. In light of these findings, clinicians should avoid performing simplified versions of WDT to evaluate IOP peaks.

The Development and Validation of a Glaucoma Health Score for Glaucoma Screening Based on Clinical Parameters and Optical Coherence Tomography Metrics

Background/Objectives: This study aims to develop and validate a Glaucoma Health Score (GHS) that incorporates multiple individual glaucoma risk factors to enhance glaucoma detection in screening environments. Methods: The GHS was developed using a retrospective dataset from two clinical sites, including both eyes of glaucoma patients and controls. The model incorporated age, central corneal thickness, intraocular pressure, pattern standard deviation from a visual field threshold 24-2 test, and two parameters from an optical coherence tomography (OCT) test: the average circumpapillary retinal nerve fiber layer thickness and the minimum thickness of the six sectors of the macular ganglion cell plus the inner plexiform layer. The GHS was then validated in two independent datasets: one from primary care sites using Maestro OCT data (test dataset 1) and another from an academic center using DRI OCT Triton (test dataset 2). Results: Both eyes of 51 glaucoma patients and 67 controls were included in the development dataset. Setting the GHS cutoff at 75 points out of 100, test dataset 1, which comprised 41 subjects with glaucoma and 41 healthy controls, achieved an area under the receiver operating characteristic curve (AUROC) of 0.98, with a sensitivity of 71% and specificity of 98%; test dataset 2, which included 53 patients with glaucoma and 53 healthy controls, resulted in an AUROC of 0.95, with a sensitivity of 75% and specificity of 96%. A decision curve analysis across all datasets demonstrated a higher net benefit for the GHS model compared to individual OCT parameters. Conclusions: The GHS offers a feasible, standardized approach for early detection of glaucoma, providing strong specificity and acceptable sensitivity, with clear decision-making benefits in screening settings.

TRPV4 overactivation enhances cellular contractility and drives ocular hypertension in TGFβ2 overexpressing eyes

The risk for developing primary open-angle glaucoma (POAG) correlates with the magnitude of ocular hypertension (OHT) and the concentration of transforming growth factor-β2 (TGFβ2) in the aqueous humor. Effective treatment of POAG requires detailed understanding of interaction between pressure sensing mechanisms in the trabecular meshwork (TM) and biochemical risk factors. Here, we employed molecular, optical, electrophysiological and tonometric strategies to establish the role of TGFβ2 in transcription and functional expression of mechanosensitive channel isoforms alongside studies of TM contractility in biomimetic hydrogels, and intraocular pressure (IOP) regulation in a mouse model of TGFβ2 -induced OHT. TGFβ2 upregulated expression of TRPV4 and PIEZO1 transcripts and time-dependently augmented functional TRPV4 activation. TRPV4 activation induced TM contractility whereas pharmacological inhibition suppressed TGFβ2-induced hypercontractility and abrogated OHT in eyes overexpressing TGFβ2. Trpv4-deficient mice resisted TGFβ2-driven increases in IOP. Nocturnal OHT was not additive to TGFβ-evoked OHT. Our study establishes the fundamental role of TGFβ as a modulator of mechanosensing in nonexcitable cells, identifies TRPV4 channel as the final common mechanism for TM contractility and circadian and pathological OHT and offers insights future treatments that can lower IOP in the sizeable cohort of hypertensive glaucoma patients that resist current treatments.

Primary Open-Angle Glaucoma Polygenic Risk Score and Risk of Disease Onset: A Post Hoc Analysis of a Randomized Clinical Trial

Importance

Primary open-angle glaucoma (POAG) is a heritable disease. A polygenic risk score (PRS) threshold may be used to identify individuals at low risk of disease onset.

Objective

To assess the utility of a POAG PRS to identify ocular hypertensive individuals at low risk of disease onset.

Design, Setting, and Participants

This is a post hoc analysis of the Ocular Hypertension Treatment Study (OHTS), a multicenter randomized clinical trial across 22 centers in the US conducted among 1636 participants with ocular hypertension from February 1994 to April 2019 with available genetic data. Of the 1636 original participants, 1077 had available genetic data; after excluding 67 for missing data, data quality concerns, or ancestry other than European or African, 1010 were included in the present analysis. Data for this report were analyzed from November 2023 to June 2024.

Exposure

From 1994-2002, participants were randomized to receive topical intraocular pressure (IOP)-lowering medications. From 2002 onwards, all participants were given topical IOP-lowering medications.

Main Outcome and Measure

Twenty-year conversion rates by POAG PRS threshold, baseline randomization status, and OHTS clinical risk tertile.

Results

Among the 1010 participants in this study, 563 (65.8%) were female, and the mean (SD) age was 55.9 (9.4) years. In a mixed-effects logistic regression model adjusted for OHTS risk factors for conversion to POAG and randomization status, a PRS under the 48th percentile was associated with a 1.49 times higher likelihood of disease-free status after 20 years of follow-up (95% CI, 1.04-2.15; P = .03; unadjusted hazard ratio [HR], 1.64; 95% CI, 1.13-2.38; P = .009), compared with high polygenic risk. When we stratified the trial cohort into nongenetic OHTS clinical risk tertiles, the largest differences in survival probability at 20 years based on PRS threshold was observed in eyes in the highest tertile, initial observation group (20-year conversion rate: 61.1% in the high polygenic risk group vs 23.8% in the low polygenic risk group; 95% CI, -63.0 to -11.6; P = .01), with randomization to early treatment partially mitigating the effect of high genetic risk (20-year conversion rate: 37.3% in the high polygenic risk group vs 24.1% in the low polygenic risk group; 95% CI, -35.6 to 9.3%; P = .32).

Conclusions and Relevance

These findings support considering use of a POAG PRS threshold to identify individuals at low risk of disease onset, with those below the PRS threshold more likely to have lower conversion rates over 20 years. Among those considered at highest risk based on the OHTS clinical risk model, early treatment may partially offset the association with high genetic risk but provide limited benefit for those with low genetic risk.

Trial Registration

ClinicalTrials.gov Identifier: NCT00000125.