Purpose:
To identify and characterize published systematic reviews (SRs) relevant to eyes and vision in major medical bibliographic databases.
Methods:
Search strategy: We developed a search strategy using keywords and terms from controlled vocabularies in the Unified Medical Language System treasure tool. We combined topical terms with terms related to SR methodology. We searched PubMed and the Cochrane Database of Systematic Reviews, the Database of Abstracts of Reviews of Effects, the Health Technology Assessment Database and the NHS Economic Evaluation Database in The Cochrane Library in November 2006. Eligibility: We included SRs, defined as full text review articles using a systematic methodology that included a clearly formulated research question, explicit methods to identify the primary studies, and predetermined inclusion and exclusion criteria. We included reviews with and without meta-analyses. SRs were eligible if they related to the etiology, epidemiology, prevention, diagnosis, intervention, practice patterns, economic evaluation, or health care utilization of eye diseases or visual impairment in humans. We excluded SRs that evaluated only animal or in vitro studies. Analyses: We reviewed the citations identified, eliminated duplicates and determined final eligibility. We classified the records by eye condition studied.
Results:
Our search identified 2,707 distinct records, of which 321 were eligible. The number of SRs increased more than 10-fold from 1992 (n = 4) to 2005 (n = 57) (see figure 1). A substantial proportion (41.1%; 132/321) concerned common aging eye conditions: 17.1% (55/321) on glaucoma, 11.2% (36/321) on AMD, 9.6% (31/321) on cataract, and 5.9% (19/321) on diabetic eye disease. Other topics with 7 or more SRs were low vision (10/321), refractive surgery (8/321) vision screening (7/321) and retinoblastoma (7/321).
Conclusions:
Our results revealed an increase in the application of SR methodology to assess the evidence in the eyes and vision literature in recent years. Enormous challenges remain, however, with many ocular conditions areas for which an evidence-based approach has not been used.
Keywords: clinical research methodology • aging