Introduction: Sightsavers is an international non-governmental organisation (NGO) working to eliminate avoidable blindness in low- and middle-income settings (LMIS). High quality evidence is essential for planning and delivering our programmes, however, evidence on what works to improve eye health in LMIS is relatively scarce and there is no single repository where all relevant research may be found.
To address this need, Sightsavers is developing eye health Evidence Gap Maps (EGMs) using the methodology developed by the International Initiative for Impact Evaluation (3ie). EGMs summarize, critically appraise and present evidence from systematic and literature reviews on a particular topic in a user-friendly format. The quality appraisal is integrated into the visual presentation of the EGM and shows where the strengths and weaknesses of evidence lie.
We will present our experiences of developing the cataract EGM including the challenges and benefits along with the initial evaluation of its potential to inform the development of EGMs for other eye diseases.

Methods:

Following a comprehensive search of relevant databases, websites and reviews of references, we sifted, and extracted data from all relevant reviews on cataract. Critical appraisal was conducted by two reviewers independently using Supported Use of Research Evidence (SURE) checklist and a summary of quality assessment was shared with the authors for comment.

Results:

Out of 1197 unique studies identified, 52 reviews met the inclusion criteria. Most reviews (18) addressed surgical methods for cataract, followed by quality of clinical care (17). Of the remainder, seven looked at risk factors/prevention, five studies were impact/economic evaluations, and three each addressed the burden of the disease and the accessibility of cataract services. Twenty-five studies were graded as being of low methodological quality, and 13 as being high quality.

Discussion:

EGMs will enable decision makers to make more informed choices by presenting the effectiveness of eye health interventions in a simple visual format. They will also enable researchers to prioritise areas where little evidence exists.