Beta-Zone PPA Changes May Herald Glaucoma in Black Patients

Genetic predisposition for POAG may also affect optic nerve head structural features, including beta-zone PPA. Experts say it’ll be useful to incorporate genetic risk scores tailed to Black patients for stratifying glaucoma risk. Photo: Zhou LX, et al. BMC Ophthalmol. 2022; 22:431. Click image to enlarge. Optic nerve head morphologic changes come in many shapes and sizes, from tilting to tissue defects. One such change, peripapillary atrophy (PPA), affects the retinal pigment epithelium, photoreceptors and choriocapillaris, causing visible choroidal vessels and sclera. When PPA occurs in Bruch’s membrane, it’s termed beta-zone PPA. This phenomenon’s association with primary open-angle glaucoma (POAG) is well known, but how it affects those of African ancestry hasn’t been studied adequately. To fill in this knowledge gap, University of Pennsylvania researchers characterized demographic, ocular and genetic factors of beta-zone PPA in Black patients. They identified strong associations with older age and high cup-to-disc ratio in their paper for Eye.From the Primary Open-Angle African American Glaucoma Genetics study, the researchers identified 3,381 eyes, 969 of which had beta-zone PPA (28.6%). Analyses revealed that this condition was associated with older age and a larger vertical c/d ratio; it was also less common in women.As for anatomical links, these nerve head changes were negatively associated with grey crescent, neural rim notching and cylindrical or bean pot cup shapes. Larger beta-zone PPA area was associated with older age and large vertical c/d ratio; it was less likely to occur with conus pigmentosus, deeper cup length, higher IOP and rounder discs. “These findings highlight unique optic nerve head structural differences that may influence beta-PPA development,” wrote the study authors.Additionally, they noted that higher polygenic risk score and presence of the SNP rs34957764 in ROCK1P1 were both associated with this condition, though this same SNP was also linked with a lesser area of beta-zone PPA. Interestingly, though no clear genetic associations were identified, beta-PPA correlated with greater RNFL loss, the researchers found.Since the study included patients already diagnosed with POAG, the researchers weren’t able to address whether peripapillary atrophy expression is predictive of POAG onset or progression. They concluded in their paper that beta-zone PPA is a “glaucomatous marker in a high-risk population” but further research is needed to evaluate its clinical utility for predicting progression and which specific characteristics are linked to progression.Click here for the journal source. Sapir T, Salowe R, Chen Y, et al. Risk factors associated with beta-peripapillary atrophy in individuals of African ancestry with primary open-angle glaucoma. Eye 2025. [Epub ahead of print]. This article was developed by the editorial staff in conjunction with experts in the field. In the process, AI may have been among the editorial tools used to meet the goals of human editors, who approved all content.