Ethnicity Based Differences in the Lamina Cribrosa Microstructure of Healthy Eyes

Abstract

Purpose : It has been shown that Asians have a high prevalence of normal tension glaucoma, while Caucasians and African-Americans have predominantly high tension glaucoma. This study compared the lamina cribrosa (LC) microstructure of a cohort of Korean and American eyes in order to discern microstructure differences between the cohorts that could contribute to this phenomenon.

Methods : The optic nerve head of 53 healthy eyes (42 subjects; 38 Korean eyes and 15 American eyes, consisting of a mixture of Caucasian and African-American eyes) was scanned 3 times during the same session with Cirrus HD-OCT (Zeiss, Dublin CA). These scans were registered and averaged to increase LC visibility using a method we have previously described. The area of the ONH featuring clearly visible LC was delineated, and scans were semi-automatically analyzed within the delineated area to segment the LC microstructure in 3D. The LC measurements of beam thickness, pore diameter, and beam/pore ratio were compared using a hierarchical linear model taking ethnicity and age into account.

Results : Baseline characteristics were similar between the cohorts (Table 1). Mean pore diameter was on average 3.78μm bigger in Asian subjects compared to non-Asian subjects (p<0.001), and beam/pore ratio was 0.33 units smaller in Asian subjects (p<0.001). No differences were detected in beam thickness.

Conclusions : The in vivo microstructure of the LC varies among different ethnicities. Further research is needed to determine the cause, effect and clinical relevance of these differences.

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.