Visual impairment in a Taiwanese population: prevalence, causes, and socioeconomic factors

We sought to estimate the prevalence of visual impairment among an elderly population in urban Taiwan, determine the causes of visual impairment, and gain information about certain socioeconomic factors associated with visual impairment.

A population-based survey of ocular diseases in residents aged 50 years or older was conducted in Peitou Precinct, Taipei, Taiwan. All participants underwent a comprehensive ophthalmic examination, including visual acuity measurement, using standardized protocols. Demographic data, marital status, employment status, and educational level were gathered through an interview.

A total of 2034 participants completed the visual acuity measurements. The prevalence of visual impairment (defined as best-corrected visual acuity in the better eye <6/18) among this population was 2.75% (95% confidence intervals: 2.04%-3.46%). Three major causes of visual impairment were cataract (30.4%), high myopic macular degeneration (25.0%), and age-related macular degeneration (14.3%). In multivariate analysis, age was positively correlated with visual impairment (P < 0.001), and higher education level was associated with a significant decrease in the odds of being visually impaired (P < 0.001). No relation was found between visual impairment and sex, or marital and employment status. CONCLUSIONS This study provides the first information about the prevalence and causes of visual impairment in Taiwan, and identifies age and educational level as the most important factors related to visual impairment. Additional educational programs should be developed to improve individual awareness of age-related ocular diseases and the availability of current ophthalmic intervention.