Prevalence of and associated factors for corneal blindness in a rural adult population (the southern Harbin eye study).

PURPOSE: To examine the distribution and causes of corneal blindness in a rural Chinese population.
METHODS: Cluster sampling of populations age > 50 was used. The protocol consisted of a detailed interview, visual acuity (VA) testing, and clinical examinations. An eye was considered to have cornea blindness if the visual acuity was < 20/400 due to a corneal disease.
RESULTS: A total of 5057 eligible subjects agreed to participate, giving an attendance rate of 91.0%. Corneal blindness in at least one eye was present in 48 participants, prevalence of 0.949% (95% CI: 0.682-1.216%) in at least one eye, which included 0.16% prevalence of corneal blindness in both eyes. The most frequent causes of corneal blindness in at least one eye included keratitis during childhood (39.6%), keratitis during adulthood (27.1%), and trauma (20.8%). We found that aging and male gender were associated with prevalence of corneal blindness. Multivariate analysis shows a higher OR of corneal blindness in subjects age 70 and older (1.746) and male gender (1.177).
CONCLUSIONS: Corneal blindness is a public health problem in southern Harbin, the majority of which is either preventable or treatable. Eye care planning must focus on corneal blindness as well as cataract.