Gray optic disc crescent: influence of ethnicity in a glaucoma population.

Purpose: To evaluate the prevalence of the gray optic disc crescent within a glaucoma population and the influence of ethnicity and other variables.

Patients And Methods: Consecutive patients of white or African American ethnicity, seen in the Glaucoma Service of Yale Eye Center, were included in the study. The 2 ethnic groups were not matched for refractive error, age, or stage of glaucoma. Stereodisc photos, suitable for detailed evaluation of disc and parapapillary features, of 1 or both eyes were selected by 1 investigator. The photos were masked to the other 2 investigators, who independently interpreted the disc and parapapillary features. The prevalence of the gray crescent in the 2 ethnic groups was compared by chi analysis. Correlation with age, sex, refractive error, intraocular pressure, and the presence and degree of glaucomatous optic neuropathy were also analyzed.

Results: Of 225 patients (447 eyes), the gray crescent was seen in one or both eyes of 32 patients (14.2%), which included 21 of the 77 [27.3%, 95% confidence intervals (CI) 9.95] African Americans and 11 of the 148 (7.4%, 95% CI 4.23) whites. The difference in prevalence of the gray crescent between the 2 ethnic groups was significant (P<0.0001). The prevalence of the gray crescent did not correlate with age, sex, refractive error, intraocular pressure or the presence or degree of glaucomatous optic neuropathy.

Conclusions: The gray optic disc crescent is a common finding within a glaucoma population, especially among persons of African heritage, but does not correlate with the presence or degree of glaucomatous optic neuropathy nor other patient variables.