Age-related macular degeneration in Chinese-Canadians

Ethnicity has long been suspected to play a role in the risk of macular degeneration as well as its neovascular complications. We carried out a study to determine the prevalence of retinal diseases in Chinese-Canadians presenting for fluorescein angiography compared to a matched group of Canadians of European origin.

We reviewed 20,000 consecutive fluorescein angiograms obtained between December 1987 and November 1993 at a tertiary referral centre for ophthalmic care in Vancouver. All patients identified by name as being of Chinese ancestry were identified and matched to a patient of European ancestry. The two groups were compared in regard to the prevalence of specific retinal diseases, including age-related macular degeneration (AMD).

Among the first 10,000 fluorescein angiograms, 417 patients of Chinese ancestry were identified, of whom 61 (14.6%) had the primary diagnosis of AMD. The rate among the patients of European ancestry was 30.4% (127/417) (odds ratio [OR] 2.12, 95% confidence interval [CI] 1.79 to 2.56) (p < 0.001). A total of 88 ethnic Chinese patients were identified among the subsequent 10,000 angiograms. Pigment epithelial detachments were more than twice as common in the overall group of ethnic Chinese patients as in their counterparts of European ancestry (OR 2.6, 95% CI 0.7 to 10.1). Choroidal neovascularization was 1.6 times more common in the latter group (95% CI 0.98 to 2.8).

The findings support the growing clinical observations of a lower prevalence of AMD in nonwhite populations in addition to an increased prevalence of pigment epithelial detachments in ethnic Chinese patients.