Six-Year Incidence and Causes of Low Vision and Blindness in a Rural Chinese Adult Population: The Handan Eye Study

Purpose: To determine the six-year incidence, risk factors, and causes of visual impairment in a Chinese population. Methods: This was a population-based study of eye disease in Chinese adults in a rural district of Handan in China. 6,830 individuals were invited to participate in 2006 and 5,394 returned for follow-up in 2012. All participants underwent standardized eye examinations. Visual impairment was defined according to WHO criteria. The incidence of visual impairment was age- and gender-standardized to the 2010 China Census. Multivariable logistic regression analysis was used to determine risk factors for visual impairment. Results: The leading causes of visual impairment were cataract and refractive error. Based on presenting visual acuity (PVA), the six-year incidence rates of low vision and blindness were 5.2% and 0.5%, respectively. Incidence of low vision was associated with older age (p < .001), less education (p < .001), diabetes (p < .05), and lower BMI (p < .001). The incidence of blindness was associated with diabetes (p < .05). Based on best-corrected visual acuity (BCVA), the six-year incidence rates of low vision and blindness were 0.8% and 0.1%, respectively. Incidence of low vision was associated with older age (p < .001) and lower BMI (p < .05). None of these factors were associated with the incidence of blindness. Conclusion: In Handan, the incidence of visual impairment was high and associated with older age, less education, diabetes, and lower BMI. The majority of cases were due to unoperated cataract and uncorrected refractive error, reflecting the need for improved eye care in this region.