title: First Prospective Cohort Study of Diabetic Retinopathy from Sub-Saharan Africa: High Incidence and Progression of Retinopathy and Relationship to Human Immunodeficiency Virus Infection.
abstract: 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.
  
  
  
  Prospective cohort study.
  
  
  
  Subjects were systematically sampled from 2 primary care diabetes clinics.
  
  
  
  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.
  
  
  
  Incidence of sight-threatening retinopathy and progression of retinopathy by 2 steps on the Liverpool Diabetic Eye Study Scale.
  
  
  
  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.
  
  
  
  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.
authors.affiliation: Malawi-Liverpool-Wellcome Trust Clinical Research Programme, and Department of Eye and Vision Science, University of Liverpool, Liverpool, England. Electronic address: philipburgess@doctors.org.uk.
authors.forename: Philip I
authors.initials: PI
authors.lastname: Burgess
authors.affiliation: Department of Eye and Vision Science, University of Liverpool, and St. Paul's Eye Unit, Royal Liverpool University Hospital, Liverpool, England.
authors.forename: Simon P
authors.initials: SP
authors.lastname: Harding
authors.affiliation: Department of Biostatistics, University of Liverpool, Liverpool, England.
authors.forename: Marta
authors.initials: M
authors.lastname: García-Fiñana
authors.affiliation: St. Paul's Eye Unit, Royal Liverpool University Hospital, and Department of Eye and Vision Science, University of Liverpool, Liverpool, England.
authors.forename: Nicholas A V
authors.initials: NA
authors.lastname: Beare
authors.affiliation: Lions Sight First Eye Unit, Queen Elizabeth Central Hospital, Blantyre, Malawi.
authors.forename: Gerald
authors.initials: G
authors.lastname: Msukwa
authors.affiliation: College of Medicine, University of Malawi, Blantyre, Malawi.
authors.forename: Theresa J
authors.initials: TJ
authors.lastname: Allain
mesh_terms: D000328:Adult; D000368:Aged; D003930:Diabetic Retinopathy / Q000453:epidemiology*; D018450:Disease Progression; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis; D015658:HIV Infections / Q000150:complications*; D006801:Humans; D015994:Incidence; D008295:Malawi / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D015995:Prevalence; D011446:Prospective Studies; D012307:Risk Factors
chemical_list: D006442:Glycated Hemoglobin