Differences in optic disc topography between black and white normal subjects

Area of Science:

• Ophthalmology
• Optometry
• Racial Health Disparities

Background:

• Optic disc topography is crucial for diagnosing glaucoma and other optic neuropathies.
• Previous studies suggest potential racial variations in optic disc morphology, but the influence of confounding factors like scleral canal size is not fully elucidated.

Purpose of the Study:

• To investigate racial differences in optic disc topography between Black and White individuals.
• To determine if these differences persist independently of scleral canal area and reference plane height.

Main Methods:

• A cross-sectional observational study involving 146 eyes from Black subjects and 97 eyes from White subjects without ocular disease.
• Retinal topography was assessed using a retinal topographer, with parameters analyzed unadjusted and adjusted for optic disc area and reference plane height.

Main Results:

• Black individuals exhibited a significantly greater optic disc area compared to White individuals.
• Most racial differences in optic disc parameters were not significant after adjusting for disc area and reference plane height.
• Black individuals showed a deeper maximum cup depth, independent of disc area and reference plane height.

Conclusions:

• Normal variations in optic disc topography between Black and White individuals are largely explained by differences in disc area and reference plane height.
• A residual racial difference in optic cup depth exists, independent of these structural parameters.
• These findings underscore the importance of considering racial variations in optic disc structure for accurate disease assessment and highlight the comparable performance of the Moorfield classification across racial groups.