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Abstract #10257 Published in IGR 6-1
Racial differences in optic disc topography: baseline results from the confocal scanning laser ophthalmoscopy ancillary study to the ocular hypertension treatment study
Zangwill LM; Weinreb RN; Berry CC; Smith AR; Dirkes KA; Coleman AL; Piltz-Seymour JR; Liebmann JM; Cioffi GA; Trick GArchives of Ophthalmology 2004; 122: 22-28
OBJECTIVE: To examine racial differences in optic disc topography among ocular hypertensive participants in the Ocular Hypertension Treatment Study. METHODS: Four hundred and thirty-nine participants from seven ocular hypertension treatment study centers who had good-quality baseline images obtained using a quantitative three-dimensional confocal scanning laser ophthalmoscope, the Heidelberg Retina Tomograph (Heidelberg Engineering, Dossenheim, Germany), were included in this study. The first 10- or 15°-field of view mean topographical image acquired was included in all analyses. Differences in Heidelberg Retina Tomograph topographical optic disc parameter measurements by self-identified race were assessed using a mixed-effects linear model to control for confounders and for the use of both eyes in the model. RESULTS: By self-attribution, 74 (17%) of the 439 participants were of African origin, 329 (75%) were white, 24 (5%) were Hispanic, and 12 (3%) were Native American, Native Alaskan, Asian, Pacific Islander, or unknown. The African American participants had statistically significantly (p < o.001) larger mean (SD) optic disc areas than the other participants, 2.17 (0.41) mm2 versus 1.87 (0.38) mm2, respectively. African American participants had a larger cup area, cup volume, cup depth, neuroretinal rim area, rim volume, and smaller rim-optic disc area ratios than the other participants. No difference between African American and the other participants was found for cup shape and retinal nerve fiber layer thickness. After controlling for optic disc area, none of the differences between African American and the other participants found in the univariate analysis remained statistically significant (p > 0.10). CONCLUSIONS: This study demonstrated in a large cohort of subjects with ocular hypertension, that African Americans have significantly larger optic discs, optic cups, neuroretinal rims, and cup-disc ratios than other racial groups. Furthermore, this study found that differences in topographical optic disc parameters between African Americans with ocular hypertension and other racial groups are largely explained by the larger optic disc area in the African Americans. These results highlight the need to consider race and optic disc size when evaluating the appearance of the optic disc in glaucoma.
Dr. L.M. Zangwill, Department of Ophthalmology, University of California, San Diego, La Jolla, CA 92093, USA. zangwill@eyecenter.ucsd.edu
Classification:
2.14 Optic disc (Part of: 2 Anatomical structures in glaucoma)
6.9.1 Laser scanning (Part of: 6 Clinical examination methods > 6.9 Computerized image analysis)