Philip I. Burgess

Epidemiology of diabetic retinopathy and maculopathy in Africa: a systematic review

Diabet. Med. 30, 399–412 (2013)

Diabetes in sub-Saharan Africa: from clinical care to health policy

Harvard TH Chan School of Public Health, Harvard University, Boston, MA, USA (Prof R Atun FRCP, Prof T Bärnighausen MD, I Postolovska ScD, S Vollmer PhD, B Ammon, A Annamreddi, A Awasthi, S Bhadriraju, J Chai MPH, J Ho BS, S S Kakarmath MBBS MS, R Kharel, M A Kyle, S C Lee MD, A Lichtman MD, J Manne-Goehler MD, M Nair MPH, O L O Okafor MPH, O Okunade MD, D Sando, A Sharma MPH, A S Syed MPH); Harvard Medical School, Harvard University, Boston, MA, USA (Prof R Atun, A Binagwaho MD, P Chipendo MD, J Manne-Goehler); Centre for Global Health, King’s College London, Weston Education Centre, London, UK (J I Davies MD); MRC/Wits Rural Public Health and Health Transitions Research Unit, School of Public Health, Education Campus, University of Witwatersrand, Parktown, South Africa (J I Davies); University of Bristol, Bristol, UK (E A M Gale FRCP); Muhimbili University of Health and Allied Sciences, and Abbas Medical Centre, Dar es Salaam, Tanzania (Z G Abbas MMed); Institute of Public Health, Faculty of Diabetes in sub-Saharan Africa: from clinical care to health policy

Prevalence of diabetic retinopathy, cataract and visual impairment in patients with diabetes in sub-Saharan Africa.

Background/aims There are few published data on the prevalence of diabetic retinopathy in sub-Saharan Africa. We report the prevalence of all grades of retinopathy and associations with systemic parameters in patients attending a secondary care diabetes clinic in Blantyre, Malawi. Methods Cross-sectional study of all patients attending for diabetes care in a hospital setting. Clinical examination and biochemical testing was performed to assess visual acuity (VA), grade of retinopathy (slit lamp biomicroscopy), microvascular complications, glycaemic control, hypertension and HIV status. Sight-threatening diabetic retinopathy (STDR) was defined as moderate preproliferative retinopathy or worse, circinate maculopathy or exudates within one disc diameter of the foveal centre or clinically significant macular oedema. Results In patients with type 2 diabetes (n=249) the prevalence (95% CI) of any retinopathy, STDR and proliferative diabetic retinopathy (PDR) was 32.5% (26.7 to 38.3%), 19.7% (14.7 to 24.6%) and 4.8% (2.2 to 7.5%), respectively. The presence of STDR was associated with albuminuria (OR 2.6; p=0.02), the presence of neuropathy (OR 3.4; p=0.005) and insulin use (OR 5.3; p=0.0004), but not with HIV status. In patients with type 1 diabetes (n= 32), the prevalence of any retinopathy, STDR and PDR was 28.1% (12.5 to 43.7%), 18.8% (5.2 to 32.2%) and 12.5% (1.0 to 24.0%), respectively. 12.1% of study subjects had VA worse than 6/18 (20/60). Conclusion This study provides baseline information on prevalence of all grades of retinopathy and STDR in consecutive cases attending an urban/semi-urban diabetes clinic in sub-Saharan Africa. Prevalence of STDR was high and in type 2 diabetes was associated with albuminuria, neuropathy and insulin use.

Diabetic retinopathy in sub-Saharan Africa: meeting the challenges of an emerging epidemic

BackgroundSub-Saharan Africa faces an epidemic of diabetes. Diabetes causes significant morbidity including visual loss from diabetic retinopathy, which is largely preventable. In this resource-poor setting, health systems are poorly organized to deliver chronic care with multiple system involvement. The specific skills and resources needed to manage diabetic retinopathy are scarce. The costs of inaction for individuals, communities and countries are likely to be high.DiscussionScreening for and treatment of diabetic retinopathy have been shown to be effective, and cost-effective, in resource-rich settings. In sub-Saharan Africa, clinical services for diabetes need to be expanded with the provision of effective, integrated care, including case-finding and management of diabetic retinopathy. This should be underpinned by a high quality evidence base accounting for differences in diabetes types, resources, patients and society in Africa. Research must address the epidemiology of diabetic retinopathy in Africa, strategies for disease detection and management with laser treatment, and include health economic analyses. Models of care tailored to the local geographic and social context are most likely to be cost effective, and should draw on experience and expertise from other continents. Research into diabetic retinopathy in Africa can drive the political agenda for service development and enable informed prioritization of available health funding at a national level. Effective interventions need to be implemented in the near future to avert a large burden of visual loss from diabetic retinopathy in the continent.SummaryAn increase in visual loss from diabetic retinopathy is inevitable as the diabetes epidemic emerges in sub-Saharan Africa. This could be minimized by the provision of case-finding and laser treatment, but how to do this most effectively in the regional context is not known. Research into the epidemiology, case-finding and laser treatment of diabetic retinopathy in sub-Saharan Africa will highlight a poorly met need, as well as guide the development of services for that need as it expands.

Posterior segment eye disease in sub-Saharan Africa: review of recent population-based studies.

To assess the burden of posterior segment eye diseases (PSEDs) in sub‐Saharan Africa (SSA).

High prevalence in Malawi of sight-threatening retinopathy and visual impairment caused by diabetes: identification of population-specific targets for intervention.

To report the prevalence of all grades of diabetic retinopathy and associations with demographic, clinical and biochemical variables in people with diabetes in Southern Malawi.

First Prospective Cohort Study of Diabetic Retinopathy from Sub-Saharan Africa: High Incidence and Progression of Retinopathy and Relationship to Human Immunodeficiency Virus Infection

Purpose To describe the prevalence, incidence, and progression of retinopathy and to report associations with demographic, clinical, and biochemical variables in people with diabetes in Southern Malawi. Design Prospective cohort study. Participants Subjects were systematically sampled from 2 primary care diabetes clinics. Methods We performed the first prospective cohort study of diabetic retinopathy from Sub-Saharan Africa over 24 months. Visual acuity, glycemic control, blood pressure, human immunodeficiency virus (HIV) status, urine albumin-to-creatinine ratio, hemoglobin, and lipids were assessed. Retinopathy was graded at an accredited reading center using modified Wisconsin grading of 4-field mydriatic photographs. Main Outcome Measures Incidence of sight-threatening retinopathy and progression of retinopathy by 2 steps on the Liverpool Diabetic Eye Study Scale. Results A total of 357 subjects were recruited to the 24-month cohort study. At baseline, 13.4% of subjects were HIV positive and 15.1% were anemic. The 2-year incidence of sight-threatening diabetic retinopathy (STDR) for subjects with level 10 (no retinopathy), level 20 (background), and level 30 (preproliferative) retinopathy at baseline was 2.7% (95% confidence interval [CI], 0.1–5.3), 27.3% (95% CI, 16.4–38.2), and 25.0% (95% CI, 0–67.4), respectively. In a multivariate logistic analysis, 2-step progression of diabetic retinopathy was associated with glycosylated hemoglobin (odds ratio [OR], 1.27; 95% CI, 1.12–1.45), baseline grade of retinopathy (OR, 1.39; 95% CI, 1.02–1.91), and HIV infection (OR, 0.16; 95% CI, 0.03–0.78). At 2 years, 17 subjects (5.8%) lost ≥15 letters. Conclusions Incidence of STDR was approximately 3 times that reported in recent European studies. The negative association of HIV infection with retinopathy progression is a new finding.

Incremental cost-effectiveness of screening and laser treatment for diabetic retinopathy and macular edema in Malawi.

Objective To investigate the economic impact of introducing targeted screening and laser photocoagulation treatment for sight-threatening diabetic retinopathy and macular edema in a setting with no previous screening or laser treatment for diabetic retinopathy in sub-Saharan Africa. Materials and methods A cohort Markov model was built to compare combined targeted screening and laser treatment for patients with sight-threatening diabetic retinopathy and macular edema against no intervention. Primary outcomes were incremental cost per quality-adjusted life year (QALY) gained and per disability-adjusted life year (DALY) averted. Primary data were collected on 357 participants from the Malawi Diabetic Retinopathy Study, a prospective, observational cohort study. Multiple scenarios were explored and a probabilistic sensitivity analysis was performed. Results In the base case (age: 50 years, service utilization rate: 80%), the cost of the intervention and the years of severe visual impairment averted per patient screened were

Diabetes in sub-Saharan Africa

209 and 2.2 years respectively. Applying the World Health Organization threshold of cost-effectiveness for Malawi (

Incidence and progression of diabetic retinopathy in Sub-Saharan Africa: A five year cohort study

679), the base case was cost-effective when QALYs were used (