[Prevalence and causes of blindness and visual impairment in China from 1990 to 2021: an analysis based on the Global Burden of Disease 2021 Database].

Objective: To investigate the prevalence and etiologies of blindness and visual impairment in China from 1990 to 2021, and to provide references for formulating prevention and treatment strategies for blindness and visual impairment. Methods: This study was an ecological trend study based on the Global Burden of Disease (GBD) 2021 database. Data on the number of cases, prevalence, age-standardized prevalence and etiologies of blindness and visual impairment in China from 1990 to 2021 were extracted. The prevalence and changes in etiological composition in different genders and age groups were analyzed. Joinpoint regression model was used to calculate the Average Annual Percentage Change (AAPC). Decomposition analysis was performed to quantify the contributions of population aging, population growth and epidemiological change to the changes in the number of cases. Results: In 2021, the number of cases of blindness, severe visual impairment and moderate visual impairment in China was 8.768 2 million, 4.178 9 million and 47.757 2 million, respectively, which increased by 64.90%, 129.47% and 139.80% compared with 1990, with AAPCs of 1.70%, 2.87% and 2.89%, respectively (all P<0.05). The age-standardized prevalence rates were 465.14 per 100 000 population, 214.09 per 100 000 population and 2 501.72 per 100 000 population, respectively, which showed changes of -28.63%, -8.73% and+7.74% compared with 1990, with AAPCs of -1.03% (P<0.05), -0.15% (P=0.281) and 0.28% (P<0.05), respectively. The prevalence of visual impairment was higher in females than in males. In 2021, the highest number of cases of blindness and severe visual impairment was in the 70-74-year age group; the highest number of cases of moderate visual impairment was in the 65-69-year age group. Population aging contributed 133.40%, 87.49% and 68.54% to the changes in the number of cases of blindness, severe visual impairment and moderate visual impairment, respectively; population growth contributed 39.82%, 23.78% and 22.18%, respectively; epidemiological change contributed -73.22%, -10.56% and 9.28%, respectively. Refractive error and cataract were the top two etiologies of blindness and visual impairment. Conclusion: The number of cases of blindness and visual impairment in China showed an upward trend from 1990 to 2021. With population growth and aging, the disease burden will further increase. Focusing on cataract in the elderly and refractive error in children and adolescents is an important strategy to reduce the burden of blindness and visual impairment in China.