Objective: To investigate the prevalence and main causes of blindness and low vision among adults aged ≥ 60 years in the suburban population of Nantong, Jiangsu, China.
Methods: It was a population-based cross-section study. Census in selecting individuals aged ≥ 60 years was conducted in two villages of suburb area in Nantong from June to August in 2008. One thousand three hundreds and ninety-one individuals received visual acuity test and eye examination, including lens examination by slit lamp. Blindness and low vision were graded by World Health Organization (WHO) visual impairment criterion and presenting visual acuity criterion, respectively. The main causes of blindness were analyzed in eyes whose visual acuity was lower than 0.05. Chi-square test and trend chi-square test were used to analyze the data.
Results: Of 1391 enumerated subjects, 1305 adults participated in the survey and the response rate was 93.82%. According to WHO visual impairment criterion, the prevalence of bilateral blindness and bilateral low vision was 0.54% and 4.06%, respectively; the prevalence of unilateral blindness was 3.37%. According to presenting visual acuity criterion, the prevalence of bilateral blindness was 2.15%, the prevalence of unilateral blindness was 7.13%. According to WHO visual impairment criterion and presenting visual acuity criterion, the prevalence of blindness was raised with increasing age (trend χ(2) = 27.97, P < 0.01). The leading cause of blindness were cataract, ocular fundus diseases and ametropia.
Conclusions: Cataract blindness continues as a significant problem among suburban elderly. There are large cataract patients that need operation in the eastern coastal region. The first important task in blindness prevention still is the elimination of cataract blindness.