Global Burden of Diseases, Injuries, and Risk Factors Study (GBD)—The Vision Loss Group—Methodology and Results of Systematic Review

Objective. To improve the accuracy of the global burden estimate of vision loss, this presentation shall describe the GBD systematic review process, with emphasis on seeking cause-specific data on the global prevalence and incidence. Background. This complete systematic assessment of the data on all diseases and injuries and produces comprehensive comparable estimates of the burden of diseases, injuries and risk factors for two time periods, 1990 and 2005. Methods. Prior to the systematic review, vision loss experts agreed on case definitions for 7 levels of presenting vision loss (visual sequelae). All articles published between 1980 and 2008 were searched among PubMed, Embase and the WHO Library using search terms that included eye diseases, visual sequelae and epidemiological terms. All non population-based studies were excluded. Full text articles were reviewed for eligibility and a quality assessment tool applied. Data abstracted yields age and sex-specific prevalence and incidence of visual sequelae, with cause-specific breakdown where possible. Results. 10,871 articles represented these global regions: Europe (33%), North America (25%), Asia (20%), Africa (12%), Australasia and Oceania (5%), Latin America (3%), Caribbean (1%), Israel (1%). Conclusions. From the perspective of vision loss, the intent is to improve the accuracy of the global burden estimate by incorporating recent population-based studies, reducing the threshold of visual impairment to 20/40, reporting on presenting VA rather than best-corrected visual acuity, and involving estimates of near visual impairment for the first time. Grants: Non