In one of the largest analyses of longitudinal SD-OCT data among a diverse population of glaucoma patients cared for in routine clinical practice, significant differences in mGCIPL rates topographically mirrored areas of significant differences in pRNFL rates in most cases. Photo: Danica J. Marrelli, OD. Click image to enlarge.

Differences in rates of change in OCT parameters between diverse racial-ethnic groups have not been investigated using a large population receiving routine care. Researchers from the

Bascom Palmer Eye Institute in Miami recently evaluated how jointly modeled rates of peripapillary retinal nerve fiber (pRNFL) and macular ganglion cell-inner plexiform layer (mGCIPL) parameters differed between racial-ethnic groups when stratified by baseline disease severity and adjusted for key ocular and demographic characteristics. Their study identified faster rates of pRNFL and mGCIPL loss among non-Hispanic Black eyes across most of the spectrum of glaucomatous disease. These findings highlighted the complex interplay of genetic, ocular and socio-environmental factors that may influence the progression of glaucoma and contribute to the observed disparities between racial-ethnic groups.

To compare rates of change in these parameters among different race and ethnicities from a large electronic health record database of subjects with or suspected of glaucoma, this study evaluated a total of 21,472 spectral-domain OCT pRNFL scans and 14,431 mGCIPL scans from 2002 eyes. A total of 200 (15.6%) and 601 (46.8%) subjects identified as non-Hispanic Black and Hispanic, respectively.

Non-Hispanic Black eyes exhibited faster rates of change in pRNFL among glaucoma suspects (global pRNFL -0.57µm/year vs. -0.37µm/year among Hispanics), mild glaucoma (superior pRNFL quadrant -1.20µm/year vs. -0.75µm/year among non-Hispanic whites) and moderate glaucoma eyes (superior pRNFL quadrant -1.31µm/year vs. -0.52µm/year among Hispanics). Non-Hispanic Black eyes exhibited faster rates of mGCIPL loss, corresponding to pRNFL rates. The global pRNFL and mGCIPL rates were strongly correlated.

Significant differences in mGCIPL rates topographically mirrored areas of significant differences in pRNFL rates in most cases. Among glaucoma suspects, the researchers observed faster thinning in the inferior pRNFL quadrant and inferior/inferotemporal/inferonasal mGCIPL sectors in non-Hispanic Black eyes. Conversely, Hispanics exhibited faster rates in the inferior pRNFL quadrant and inferonasal mGCIPL sector among mild glaucoma eyes, although the former was not statistically significant. Among moderate glaucoma eyes, the superior pRNFL quadrant and superotemporal mGCIPL sector both featured faster rates among non-Hispanic Black eyes.

“These topographically correlated findings strengthen the likelihood of key differences between racial-ethnic groups,” the research team wrote in their paper.

“In our study, central corneal thickness (CCT) was significantly lower among non-Hispanic Black eyes, potentially suggesting a difference in sclera and lamina cribrosa biomechanics, which may dictate how elevated IOP or IOP fluctuations impact pRNFL and mGCIPL loss,” they added.  “These findings highlight the complex interplay of genetic, ocular and socioenvironmental factors that may influence the progression of glaucoma and contribute to the observed disparities between racial-ethnic groups.”

They concluded that racial-ethnic differences must be considered in the management of glaucoma patients, given the potential for a more rapid rate of disease progression within certain groups.