Systematic reviews and meta-analyses in eyes and vision: first steps in identifying gaps in ophthalmology research

Ssemanda E1, Li T1, Dickersin K1
1Cochrane Eyes and Vision Group, USA

Background: Systematic reviews are the highest level of research evidence. Identifying and characterizing all systematic reviews in eyes and vision will help to detect gaps in ophthalmology research.

Objectives: We developed a database of systematic reviews and meta-analyses in eyes and vision and described the reports.

Methods: We identified systematic reviews, using a detailed search strategy in PubMed, EMBASE, and The Cochrane Library in 2009, and updated the search in 2012. We imported systematic reviews into an EndNote database and retrieved the full-texts. We considered a systematic review to be eligible if it examined a specific question and used explicit, pre-specified scientific methods to identify, select, assess, and summarize similar but separate studies. To ensure the identification of all systematic reviews, we considered reports with systematic review or meta-analysis in the title, subheading or text. We included co-publications and previous versions of Cochrane Reviews. One author assessed the characteristics of each report.

Results: Our search found 7676 citations, of which, we included 1005 systematic reviews. Nearly 19% of reports were current or previous versions of Cochrane Reviews. Most systematic reviews focused on glaucoma (18%), age-related macular degeneration (13%), cataract (9%), or diabetic retinopathy (7%). Systematic reviews were published from 1985 to 2012. The number of systematic reviews rose from four reports published in 1980–1989 to 58 reports available in 1990–1999 and 542 reports issued from 2000 to2009. While nearly 68% of systematic reviews examined an intervention, 13% of reviews investigated etiology. Approximately 12% of reviews focused on diagnostic tests or prognosis. Only 7% of reviews had another focus (e.g. cost-effectiveness).

Conclusions: We developed a database of systematic reviews and meta-analyses in eyes and vision. Most reviews focused on common eye diseases and assessed interventions. The number of systematic reviews in ophthalmology has increased in recent decades.