Factors Associated with Large Cup-to-Disc Ratio and Blindness in the Primary Open-Angle African American Glaucoma Genetics (POAAGG) Study

Abstract

Background/Aims: Primary open-angle glaucoma (POAG) disproportionately affects individuals of African ancestry. In these patients’ eyes, a large cup-to-disc ratio (LCDR > 0.90) suggests greater retinal ganglion cell loss, though these patients often display varied visual ability. This study investigated the prevalence and risk factors associated with LCDR in African ancestry individuals with POAG and explored the differences between blind (>20/200) and not blind (≤20/200) LCDR eyes. Methods: A case–control methodology was used to investigate the demographic, optic disc, and genetic risk factors of subjects in the Primary Open-Angle African American Glaucoma Genetics Study. Risk factors were analyzed using univariable and multivariable logistic regression models with inter-eye correlation adjusted using generalized estimating equations. Results: Out of 5605 eyes with POAG, 1440 eyes (25.7%) had LCDR. In the multivariable analysis, LCDR was associated with previous glaucoma surgery (OR = 1.72), increased intraocular pressure (OR = 1.04), decreased mean deviation (OR = 1.08), increased pattern standard deviation (OR = 1.06), thinner retinal nerve fiber layer (OR = 1.05), nasalization of vessels (OR = 2.67), bayonetting of vessels (OR = 1.98), visible pores in the lamina cribrosa (OR = 1.68), and a bean-shaped cup (OR = 2.11). Of LCDR eyes, 30.1% were classified as blind (≤20/200). In the multivariable analysis, the statistically significant risk factors of blindness in LCDR eyes were previous glaucoma surgery (OR = 1.72), increased intraocular pressure (OR = 1.05), decreased mean deviation (OR = 1.04), and decreased pattern standard deviation (OR = 0.90). Conclusions: These findings underscore the importance of close monitoring of intraocular pressure and visual function in African ancestry POAG patients, particularly those with LCDR, to preserve visual function.

Paving the way while playing catch up: mitochondrial genetics in African ancestry primary open-angle glaucoma

“…Improvements have been made in enrollment of minority race and ethnic group individuals in U.S. clinical trials over the past decades although they are still underrepresented ( 62 ). Large-sample African American genetic studies are beginning to emerge, such as the POAAGG study containing 10,255 participants at the time of writing ( 67 ).…”

Study on Genotypes and Phenotypes of Neurodegenerative Diseases

“…The role of genetic factors in contributing to ethnic differences in health and disease is becoming increasingly recognised. Anusha Mamidipaka and colleagues examined the demographic, optic disc, and genetic risk factors for a large cup-to-disc ratio (LCDR) presentation and its subsequent progression to visual impairment or blindness in a large cohort of individuals of African ancestry that were recruited from the Primary Open-Angle African American Glaucoma Genetics (POAAGG) study [ 7 ]. No significant associations were found between genetic variants and LCDR or blindness, while previous glaucoma surgery, increased intraocular pressure, decreased mean deviation, and decreased pattern standard deviation were statistically significant risk factors for blindness in LCDR eyes.…”