Prevalence and incidence of dry eye in the USA: a systematic review protocol

IntroductionDry eye is a multifactorial chronic condition characterised by tear film insufficiency and instability, and ocular symptoms including foreign body sensation, itching, irritation, soreness and visual disturbance. The prevalence and incidence of dry eye are major determinants of the magnitude of economic and societal costs of the disease. This protocol proposes a systematic review and meta-analysis of the prevalence and incidence of dry eye in the USA.Methods and analysisWorking with an information specialist, we will develop search strategies for Ovid Medline and Embase for population-based cross-sectional and cohort studies involving US-based populations that report the prevalence and/or incidence of dry eye. We will include studies involving persons of all ages from 1 January 2010 to the current date with no language restrictions. We will also hand-search references of included studies, dry eye epidemiology-related systematic reviews, clinical practice guidelines and literature provided by agencies and organisations. Two investigators will independently screen the titles and abstracts, and then full-text reports to determine eligibility. One investigator will extract study data and perform risk of bias assessments using tools designed specifically for prevalence and incidence studies. A second investigator will verify all extracted study data and risk of bias assessments. We will assess heterogeneity, qualitatively and quantitatively. When appropriate, we will meta-analyse prevalence and incidence estimates.Ethics and disseminationThis review does not require approval by an ethics committee because it will use published studies. We will publish our results in a peer-reviewed journal and present at relevant conferences.PROSPERO registration numberCRD42021256934.