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Availability of evidence on cataract in low/middle-income settings: a review of reviews using evidence gap maps approach
  1. Bhavisha Virendrakumar1,
  2. Emma Jolley1,
  3. Iris Gordon2,
  4. Cova Bascaran3,
  5. Elena Schmidt1
  1. 1Research department, Sightsavers, Haywards Heath, UK
  2. 2Cochrane Eyes and Vision Group, International Centre for Eye Health, London School of Hygiene & Tropical Medicine, London, UK
  3. 3Clinical Research Department, Faculty of Infectious and Tropical Diseases, International Centre for Eye Health, London School of Hygiene & Tropical Medicine, London, UK
  1. Correspondence to Bhavisha Virendrakumar, Sightsavers, 35 Perrymount Road, Haywards Heath, West Sussex RH16 3BW, UK; bvirendrakumar{at}


Background Despite high-quality evidence being essential for planning and delivering eye health programmes, evidence on what works is relatively scarce. To address this need, we developed eye health Evidence Gap Maps (EGMs) with the first one focusing on cataract. These maps summarise, critically appraise and present evidence in a user-friendly format. This paper presents experiences of developing the cataract gap map and discusses the challenges and benefits of the process.

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

Results A total of 52 reviews were included in the map. The majority of the reviews addressed quality of clinical care (20) and types of treatment (18). Overall, 30 reviews provided strong evidence in response to the research question, 14 reviews showed weak or no evidence and in 14 reviews the results were inconclusive. 14 reviews were regarded as high quality, 12 were medium quality and 26 were graded as low quality. To verify the validity of the Supporting the Use for Research Evidence (SURE) checklist, studies were also appraised using the Scottish Intercollegiate Guidelines Network (SIGN) tool. Based on the κ statistics test, results showed excellent agreement between the two checklists (K=0.79).

Discussion EGMs support policy makers and programme managers to make informed decisions and enable researchers to prioritise future work based on the most evident gaps on knowledge.

  • Eye (Globe)
  • Field of vision
  • Vision
  • Epidemiology

This is an Open Access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:

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  • Contributors BV contributed towards the conception and design; drafted the manuscript and approved the final version. EJ and ES contributed to the content of the paper, reviewed it critically for substantial intellectual content and approved the final version. IG and CB provided their input towards the paper.

  • Competing interests None declared.

  • Provenance and peer review Not commissioned; externally peer reviewed.

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