Prevalence and Factors Associated with Visual Impairment in Children: Protocol for a Systematic Review and Meta-Analysis

Purpose: Visual impairment or blindness in newborns and children is a serious public health concern, due to highly negative effects on their development and social activity.In order to set policies and priorities and to evaluate global eye health, it is valuable to have contemporary information on the prevalence and causes of visual impairment in children.This article presents a protocol for a systematic review and meta-analysis that plans to evaluate the global prevalence and risk factors associated with visual impairment or blindness in children, including congenital, early, or late onset.Methods: Scientific literature from the following databases will be investigated: PubMed, EMBase, Cochrane Library.The primary outcome is the prevalence of irreversible visual impairment or blindness with congenital onset or onset during childhood (birth to 18 years).The secondary outcome is the difference of risk factors associated with visual impairment or blindness in children among age groups, continents, and between developing countries and advanced countries.Randomized controlled trials, quasi-experimental studies, nonrandomized comparative and non-comparative studies and case series will be included.The risk of bias will be assessed by using the Qualitative Assessment Tool for Quantitative Studies (McMaster University).If aggregation of data is possible for a subsection of studies, we will pool data using meta-analysis techniques.If aggregation of data is not possible, a qualitative synthesis will be presented.We will assess the quality and strength of the overall body of evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE).The systematic review will follow the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations.Conclusions: Our study will establish the epidemiological evidence of visual impairment or blindness in children.We anticipate that our findings will be of interest to healthcare professionals and policy makers.