Abstract: Objective·To explore the relationship between sleep duration and the risk of diabetic retinopathy（DR） by performing a meta-analysis.Methods·The databases of Cochrane Library, PubMed, Embase, Web of Science, SinoMed, CNKI, VIP, and WanFang were searched for eligible studies regarding the relationship between sleep duration and the risk of DR up to April 2021. English search terms included "sleep" "sleep duration" "sleep time""sleeping habit" "quantity of sleep diabetic retinopathy" and "retinal diseases". Chinese search terms included "睡眠" "睡眠时间" and "糖尿病性视网膜病变 ". The type of literature was observational studies, including cross-sectional studies, case-control studies, and cohort studies. Two researchers independently screened the literature and extracted data. The extracted data included the first author, country, publication time, study type, sample size,mean age, exposure assessment, sleep duration, outcome assessment, adjusted variables. The Newcastle-Qttawa Scale（NOS） was used to evaluate the quality of the included studies and a meta-analysis was performed by using R 4.0.4 software. Results·A total of 1 146 documents were retrieved, and5 met the inclusion criteria, including 5 627 study subjects. Results showed that long sleep duration was positively correlated with the risk of any DR [the combined odds ratio（OR） in the fixed-effect model and random-effect model both were 2.05, 95% confidence interval（CI） 1.37-3.05) ], while short sleep duration was not associated with the risk of any DR(OR in the fixed-effect model and random-effect model were 0.89, 95%CI 0.72-1.10 and 0.98, 95%CI0.71-1.37, respectively], but it was related to the risk of moderate DR（OR in the fixed-effect model and random-effect model were 2.07, 95%CI 1.29-3.33 and 2.06, 95% CI 1.18-3.58, respectively）. Short sleep duration was not associated with the risk of vision-threatening diabetic retinopathy（OR in the fixedeffect model and random-effect model both were 0.92, 95%CI 0.58-1.47）. Conclusion·Sleep duration is significantly associated with the risk of DR, in which too much sleep is a risk factor, while short sleep is to be further determined by research. As a modifiable factor at the individual level, the role of sleep intervention in the management of DR should be further emphasized.

Key words: sleep duration, diabetic retinopathy, meta-analysis