Prevalence and causes of visual impairment in a rural North-east China adult population: a population-based survey in Bin County, Harbin
Purpose: To investigate the prevalence and causes of visual impairment in a rural population in north-east China.Methods: A population-based study was conducted within Bin County, Harbin of north-east China. Low vision and blindness were defined using the World Health Organization categories of visual impairment. The prevalence of visual impairment was estimated, and causes were identified based on best-corrected visual acuity (BCVA) as well as presenting visual acuity (VA).Results: Out of 5764 people, 4956 (86.01%) aged older than 40 participated in the study. The prevalence of visual impairment, low vision and blindness based on presenting VA was 9.6% (BCVA, 6.6%), 7.7% (BCVA, 4.9%) and 1.9% (BCVA, 1.7%), respectively. Taking the presenting VA, cataract (44%)