Abstract
Purpose: :
This pilot study aims to investigate the prevalence and risk factors for the major causes of visual impairment and loss among Chinese–Americans in San Francisco. No large survey has been conducted to evaluate the prevalence of eye disease in this population residing in the U.S. It is anticipated that the study will enhance awareness of eye disease and improve vision care in this population.
Methods: :
This is a cross–sectional study targeting the Chinese–American community in San Francisco age 40 years or older. Recruitment was performed door to door and through screening of entire housing complexes. An enrollment questionnaire was completed and a full eye exam was performed. Low vision and blindness were defined according to the World Health Organization categories of visual impairment (BCVA in the eye with better vision worse than 20/60 to a lower limit of 20/400 and worse than 20/400 respectively).
Results: :
251 participants were screened: 80 males (32%) and 171 females (68%). The mean age of the participants was 70.3 years (range 40–91). The mean spherical equivalent refraction in the right eye was –0.62 ± 2.67 diopters (range –19.0 to +7.5 diopters). The mean spherical equivalent refraction in the left eye was –0.72 ± 3.08 diopters (range –22.75 to +7.25 diopters). A total of 12 participants (4.8%) met the World Health Organization criteria of low vision, and 2 participants (0.80%) met the criteria for blindness. The leading cause of visual impairment was cataracts (58%), followed by glaucoma (17%), then followed equally by age–related macular degeneration, hypertensive retinopathy and other retinal disease (8% each). Of the two cases of blindness found, one was from chronic angle closure glaucoma and the other due to traction retinal detachment associated with severe proliferative diabetic retinopathy.
Discussion: :
This pilot study suggests that the rates of low vision and blindness are similar to those found in Chinese populations in Asia. Cataract appears to be the leading cause of visual impairment, followed by glaucoma, a pattern similar to that seen amongst African Americans.
Conclusions: :
The results thus suggest that the cause–specific pattern vision loss in Chinese–Americans differs substantially from certain other groups of individuals residing in the U.S. Given the lack of population–based data on the prevalence of eye diseases and visual impairment among Asian–Americans, who make up over 4% of the US population, and constitute the fastest–growing racial group in the country, more precise population–based data are needed.
Keywords: clinical (human) or epidemiologic studies: prevalence/incidence • clinical (human) or epidemiologic studies: outcomes/complications • clinical (human) or epidemiologic studies: risk factor assessment