Epidemiology of Diabetic Retinopathy and Maculopathy In Africa: A Systematic Revie

Abstract

Review Article Epidemiology of diabetic retinopathy and maculopathy in Africa: a systematic review P. I. Burgess 1,2 , I. J. C. MacCormick 1,2 , S. P. Harding 2 , A. Bastawrous 3 , N. A. V. Beare 4 and P. Garner 5 1 Malawi–Liverpool–Wellcome Trust Clinical Research Programme, Queen Elizabeth Central Hospital, College of Medicine, Blantyre, Malawi, 2 Department of Eye and Vision Science, University of Liverpool, Liverpool, 3 International Centre for Eye Health, Clinical Research Department, London School of Hygiene and Tropical Medicine, London, 4 St Pauls Eye Unit, Royal Liverpool University Teaching Hospital and 5 International Health Group, Liverpool School of Tropical Medicine, Liverpool, UK Accepted 18 July 2012 Abstract Aim To summarize findings from studies reporting the prevalence and incidence of diabetic ret inopathy and diabetic maculopathy in African countries in light of the ris ing prevalence of diabetes mellitus. Methods Using a predefined search strategy, we systematically se arched MEDLINE, EMBASE, S cience Citation index and Conference Proceedings Citation index, Af rican Index Medicus and the grey literature database ‘OpenSIGLE’ for studies published between January 1990 and February 2011. Included studies reported p revalence or incidence of diabetic retinopathy or diabetic maculopathy of subjects with diabetes resident in African countries. Results Sixty-two studies from 21 countries were included: three popul ation-based surveys; two cohort studies; five case–control studies; 32 diabetes clinic-based, nine eye c linic-based and 11 other hospital-based survey s. Included studies varied considerably in terms of patient selection, method of assessing the eye and re tinopathy classification. In populat ion-based studies, the reported prevalence range in patients with diabetes for diabetic retinopat hy was 30.2 to 31.6%, proliferati ve diabetic retinopathy 0.9 to 1.3%, and any maculopathy 1.2 to 4.5%. In diabetes clinic-based su rveys, the reported prevalence range for diabetic retinopathy was 7.0 to 62.4%, proliferative diabeti c retinopathy 0 to 6.9%, and any maculopathy 1.2 to 31.1%. No obvious association between prevalence and income level of the country was detected. Conclusions Large, community-based cross-sect ional and cohort studies are needed to i nvestigate rates and determinants of prevalence of diabetic retinopathy, incide nce and progression in Africa. Consensus i s needed on the most appropriate methods of identification and classification of retinopathy for research and clinical practice. Estimates of prevalence of diabetic retinopathy, proliferative diabetic r etinopathy and maculopathy are comparable w ith recent European and American studies.