Screening for Diabetic Retinopathy

doi:10.1059/0003-4819-116-8-660

Screening for Diabetic Retinopathy

Abstract

▪ Purpose: To determine the appropriate patients, methods, and timing for screening for diabetic retinopathy.

▪ Data Sources: Relevant articles were identified through prominent review articles, the authors' files, recommendations from experts, and a MEDLINE search (1986 to the present); additional references were selected from the bibliographies of identified articles.

▪ Study Selection: Selection of articles on the natural history of retinopathy was limited to large clinical series and formal epidemiologic studies of defined populations. Selection of articles on the therapeutic effect of photocoagulation and of glycemic control was limited to randomized trials. Sources bearing on the accuracy of screening modalities were necessarily more varied.

▪ Data Extraction: For important variables, individual estimates from multiple studies are presented rather than a single meta-analytic summary estimate.

▪ Results: Screening for retinopathy is justifiable if early detection leads to less vision loss at an acceptable cost. The evidence shows that 1) laser therapy reduces the rate of vision loss by 50% among patients with proliferative retinopathy and macular edema, conditions that are often asymptomatic; 2) duration of diabetes is the main risk factor for retinopathy; and 3) standard ophthalmoscopic examination has only moderate sensitivity (about 80% in research settings) and specificity (> 90% for proliferative retinopathy but lower for macular edema), making seven-field stereo-photography a more accurate method. Estimates of cost effectiveness indicate that screening for retinopathy not only saves years of vision but may be cost saving from a societal perspective.

▪ Conclusions: Screening for retinopathy in patients with diabetes, and subsequent photocoagulation therapy for those who have high risk macular edema or proliferative retinopathy, is clearly beneficial.

[Note that sections in this review are numbered so that they can be identified with cross-references as supporting evidence in the article, "Screening Guidelines for Diabetic Retinopathy," published in the Clinical Guideline section of this issue; see pages 683-685.—The Editors]

Article and Author Information

From Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts; and Johns Hopkins University and Hospital, Baltimore, Maryland. For current author addresses, see end of text.
Grant Support: In part by a grant from the Agency for Health Care Policy and Research (1 RO1 HS06665). Dr. Singer was supported, in part, by a Henry J. Kaiser Family Foundation Faculty Scholar Award in general internal medicine.
Requests for Reprints: Daniel E. Singer, MD, General Internal Medicine Unit, Bulfinch 1, Massachusetts General Hospital, Boston, MA 02114.
Current Author Addresses: Dr. Singer: General Internal Medicine Unit, Bulfinch 1, Massachusetts General Hospital, Boston, MA 02114. Dr. Nathan: Diabetes Unit, Massachusetts General Hospital, Boston, MA 02114.

Dr. Fogel: Diabetes Center, New England Sinai Hospital, 150 York Street, Stoughton, MA 02072.

Dr. Schachat: The Wilmer Ophthalmological Institute, The Johns Hopkins University and Hospital, Wilmer 200, 600 North Wolfe Street, Baltimore, MD 21205.