Cataract evidence gap map

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What this map shows

At Sightsavers, our EGMs summarise, appraise, and present evidence from systematic or literature reviews.

The cataract EGM summarises evidence from 86 reviews. The reviews are unevenly distributed across the sectors, with most addressing risk factors and prevention of cataract (25), closely followed by quality of clinical care (23) and treatment of cataract (21). Very little evidence is identified in terms of access to cataract-related health care services (7), economic evaluations of interventions (4) and epidemiology (4). Therefore, this gap map shows that there are clear gaps in evidence at the health systems sector level. No reviews are identified for cataract-related screening and quality of non-clinical care.

A total of 37 reviews are of low confidence, of which 22 provide strong evidence in response to the research question they set out to answer. 22 reviews on the map are of medium quality, where the majority (15) show strong evidence in response to their research question. Finally, a total of 27 reviews are of low confidence; 22 of these provide strong evidence in response to their research question. Very few reviews provide inconclusive or weak evidence in response to author’s research question, regardless of confidence level.

A special thank you to Dr. Baixiang Xiao for supporting in the review of studies written in Chinese.

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This evidence gap map was last updated March 2020.
Help us keep this gap map up to date by sending us an email: [email protected]


Sightsavers (2020). Cataract Evidence Gap Map [online] Available at: [Add date accessed]

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