Optic nerve head drusen in black patients.

BACKGROUND

Several studies have suggested racial differences in the prevalence of optic nerve head drusen (ONHD). We aimed to determine the percentage of patients with ONHD who are black and to describe the clinical, ophthalmoscopic, and perimetric findings in these patients.

METHODS

We conducted a retrospective chart review of all patients with ONHD seen at our institution between 1989 and 2010. Only black patients with ONHD confirmed on either funduscopy or B-scan ultrasonography were included. Demographic and clinical findings in these patients were recorded and analyzed.

RESULTS

Of the 196 patients with confirmed ONHD, 10 (5.1%) were black. This included 7 females and 3 males with ages ranging from 8 to 61 years. Six of the 10 patients had bilateral ONHD. The ONHD were buried in 11 of 16 eyes and exposed in 5 of 16 eyes. Fifteen of 16 eyes with ONHD had small cupless optic nerve heads. Visual fields were normal in 4 of 16 eyes with ONHD. In the remainder, visual field defects included an enlarged blind spot (5 eyes), constricted field (5 eyes), nasal defect (2 eyes), central defect (1 eye), and generalized depression (1 eye). Visual field defects were present in 4 of 5 eyes (80%) with exposed ONHD and 8 of 11 eyes (72.7%) with buried ONHD. None of the patients were related, and none of their examined family members had exposed ONHD on funduscopic examination.

CONCLUSIONS

ONHD are rare in blacks, possibly due to the presence of a larger cup-to-disc ratio or a lack of predisposing genetic factors. Visual field defects are common in black patients with both exposed and buried ONHD.