Exploring ethnic and racial differences in intraocular pressure and glaucoma: The Canadian Longitudinal Study on aging.

Purpose: To determine whether self-reported race/ethnicity is associated with intraocular pressure (IOP) and glaucoma and to explore whether any associations are due to social, behavioral, genetic, or health differences. Design: Cross-sectional analysis of population-based data. Methods: We used the Canadian Longitudinal Study on Aging Comprehensive Cohort, which consists of 30,097 adults aged 45-85 years. Race/ethnicity was self-reported. Corneal-compensated intraocular pressure (IOP) was measured in mmHg using the Reichert Ocular Response Analyzer. Participants were asked to report if they have ever had a diagnosis of glaucoma and whether they used eye care in the past year. A glaucoma polygenic risk score (PRS) was calculated. Logistic and linear regression models were used. Results: Black individuals had higher mean IOP levels (beta coefficient (ß) = 1.46; 95% confidence interval [CI], 0.62, 2.30) while Chinese, Japanese and Korean (ß = -1.00; 95% CI, -1.63, -0.38) and Southeast Asian and Filipino individuals (ß = -1.56; 95% CI, -2.68, -0.43) had lower mean IOP levels as compared to White individuals after adjustment for sociodemographic, behavioral, genetic, and health-related variables. Black people were more likely to report glaucoma as compared to White people after adjustment (odds ratio [OR] = 2.43; 95% CI, 1.27, 4.64). Conclusion: Racial and ethnic differences in IOP and glaucoma were identified. Adjusting for sociodemographic, behavioral, genetic, and health-related variables did not fully explain these differences. Longitudinal research is needed to further explore the reasons for these differences and to understand their relevance to disease pathogenesis and progression.

Sensitivity and specificity of the uniform field electroretinogram in glaucoma detection in comparison to the pattern electroretinogram.

PURPOSE: To determine the ability of the photopic negative response (PhNR) of the uniform field electroretinogram (UF-ERG) to identify early glaucomatous changes in comparison to the checkerboard and bar stimuli of the pattern electroretinogram (PERG). METHODS: Forty-nine glaucoma patients were classified into two groups: glaucoma-suspect (23 eyes) and early to moderate glaucoma (30 eyes), based on their clinical examination and the results of standard automated perimetry. Thirty patients (30 eyes) with intraocular pressures (IOP) of 21 mmHg or less, with no history of reported high IOP, were included as controls. PERG and UF-ERG recordings were obtained on a Diagnosys D-341 Attaché-Envoy System. Visual field testing was done only for glaucoma-suspect and glaucoma patients. RESULTS: All three tests (PERG bar stimulus, PERG checkerboard stimulus and PhNR) displayed significantly prolonged peak times for glaucoma and glaucoma-suspect patients, with delays ranging from 7.8 to 14.8%, depending on the test. The PERG bar stimulus also showed a significantly lower N95 amplitude for both glaucoma groups (with reductions of 26.0% and 33.0% for glaucoma-suspect and glaucoma groups, respectively). The PERG checkerboard N95 amplitude component had high sensitivity for detecting glaucoma patients but a low specificity (97% and 37%, respectively; AUC = 0.61). Overall, the PhNR peak time showed the highest sensitivity and specificity (77% and 90%, respectively; AUC = 0.87). CONCLUSIONS: PERG bar stimuli and the PhNR of the UF-ERG can be used in the clinical setting to detect glaucoma-related changes in glaucoma-suspect and glaucoma patients. However, our data confirm that the PhNR peak time has the best combined sensitivity and specificity.

XIAP gene therapy effects on retinal ganglion cell structure and function in a mouse model of glaucoma.

Glaucoma is a prevalent neurodegenerative disease that is characterized by progressive visual field loss. It is the leading cause of irreversible blindness in the world. The main risk factor for glaucoma is elevated intraocular pressure that results in the damage and death of retinal ganglion cells (RGCs) and their axons. The death of RGCs has been shown to be apoptotic. We tested the hypothesis that blocking the activation of apoptosis may be an effective strategy to prevent RGC death and preserve functional vision in glaucoma. In the magnetic microbead mouse model of induced ocular hypertension, inhibition of RGC apoptosis was targeted through viral-mediated ocular delivery of the X-linked inhibitor of apoptosis (XIAP) gene, a potent caspase inhibitor. Pattern electroretinograms revealed that XIAP therapy resulted in significant protection of both somal and axonal RGC function in glaucomatous eyes. Histology confirmed that the treated optic nerves showed preservation of axon counts and reduced glial cell infiltration. These results show that XIAP is able to provide both functional and structural protection of RGCs in the microbead model of glaucoma and provide important proof-of-principle for XIAP's efficacy as a neuroprotective treatment for glaucoma.

Late bleb leak management with trabeculectomy shutdown, Baerveldt glaucoma device implantation, and titratable tube lumen size.

PURPOSE: To report a case of late subconjunctival bleb leak, and its management to preserve vision and achieve optimal pressure control in a patient with advanced glaucoma, a 3+ Seidel positive bleb leak, and hypotony maculopathy in the better-seeing eye. DESIGN: Case Report. METHODS: Shutdown of the earlier trabeculectomy site with a scleral graft was achieved before insertion of a 250-mm Baerveldt glaucoma device. An absorbable ligature was used around the tube to prevent early postoperative hypotony. Additional pressure control was obtained by using a permanent polypropylene ligature to decrease the effective lumen size after the resorbence of the vicryl ligature. This suture was left in a location that would be accessible to laser suture-lysis, or manual removal if necessary. RESULTS: Intraocular pressure at 1 year postoperatively was 13 mm Hg on no medications with resolution of the macular folds and 3 lines of improvement of Snellen corrected distance visual acuity. The leak was completely resolved. CONCLUSION: Excellent pressure control was achieved in the surgical management of a late onset bleb leak by shutting down the old trabeculectomy, and inserting a new Baerveldt tube shunt with an adjustable lumen size.

The ocular manifestations of Jacobsen syndrome: a report of four cases and a review of the literature.

PURPOSE: We report ophthalmic manifestations in four Jacobsen syndrome cases, review the literature, and suggest phenotype-genotype correlations. METHODS: Chart review of Ocular Genetics Program patients at The Hospital for Sick Children, Toronto, Canada. RESULTS: Four del11qter cases are presented. Hypertelorism/telecanthus, abnormally slanted palpebral fissures, abnormal retinal findings, nasolacrimal duct obstruction, anomalous extraocular muscles, amblyopia, and microcornea were found. CONCLUSIONS: We report typical findings and novel ocular presentations. Visual prognosis is generally good. Retinal dysplasia and coloboma seem associated with del11q23. ABCG4, NCAM, and Mfrp are candidate genes in this region that theoretically may be disrupted.