Changed trends of major causes of visual impairment in Sichuan, China from 1987 to 2006

Prevalence and Causes of Visual Impairment in Adults in Binhu District, Wuxi, China

Background

Previously reported data has guided the treatment and prevention of blindness. This study aimed to evaluate the current prevalence and causes of visual impairment among adults who were 50 years old and older in the Binhu District of Wuxi City, China.

Material/Methods

A randomized sample of stratified clusters was used to analyze individuals from 30 basic sampling units in Wuxi Binhu District. Visual impairment was defined according to World Health Organization (WHO) standards.

Results

A total of 6725 people who were at least 50 years old participated in this study. According to WHO standards, bilateral low vision and blindness prevalence were both higher in women than in men (low vision: 6.5% vs. 5.2%; and blindness: 1.4% vs. 0.8%; P=0.022 and P=0.039, respectively). The incidence of bilateral visual impairment increased significantly with age (P<0.001 and P<0.001, respectively). Further studies showed that the main causes of bilateral low vision were cataract, high myopic macular degeneration (MMD), and age-related macular degeneration (AMD). The main causes of bilateral blindness were cataract, MMD, and eye loss/atrophy, while the main causes of monocular low vision were cataract, MD, and AMD. The main causes of monocular blindness were cataract, eye loss/atrophy, and AMD.

Conclusions

The prevalence of low vision and blindness remains high in the Binhu District of Wuxi City in China, especially among older women. In our study, cataracts were the leading cause of visual impairment. Our study highlights that some efforts should be initiated to prevent and treat blindness and low vision. Additional causes of visual impairment were MMD, AMD, and eye loss/atrophy.