Demographic, medical and visual aspects of Dia- betic Retinopathy (DR) and Diabetic Macular Edema (DME) in South African diabetic patients*

Abstract

Objective: To investigate some of the demographic, medical, and visual aspects of diabetic retinopathy (DR) and diabetic macula edema (DME) in diabetics attending an urban clinic in Johannesburg, Gauteng.

Design: In this cross-sectional study, 202 diabetic patients were recruited. Demographic variables included age, gender, race, age of diagnosis, duration of diabetes mellitus (DM), and social habits. Medical variables included systemic conditions present, blood pressures, body mass indices (BMI), lipid profiles, glycerated haemoglobin (HbA1c), and other biochemical data. Visual variables included distance, pinhole and near visual acuities, contrast visual acuities (CVA), refractive status, colour vision, central visual field evaluation with the Amsler grid, intraocular pressures (IOP), fundus photography and administration of the Impact of Visual Impairment (IVI) questionnaire. All variables were compared between diabetic subjects with and with-out DR and DME in both right and left eyes.

Results: Overall prevalence of DR was 22.8% and DME 12.5%. In DR subjects, significant results indicated that Whites were more likely to present with DR (p = 0.002). Subjects with DR had a higher mean duration of DM (p = 0.002) and a higher mean diastolic blood pressure (p = 0.035). Autorefraction suggested that more myopia and less astigmatism might be associated with DR. A higher mean CVA at the 2.5% level in DR was significant in both the right eyes (p = 0.042) and left eyes (p = 0.035). These subjects also reported a higher mean IVI score in the consumer and social interaction domain (p = 0.032). Similarly, DME subjects displayed a higher mean duration of DM (p = 0.042) and a higher mean diastolic blood pressure (p = 0.048). A higher mean CVA was associated at both the 10% level: right eyes (p = 0.021); and left eyes (p = 0.046), and at the 2.5% level: right eyes (p = 0.033) and left eyes (p = 0.045). A higher mean IVI score in leisure and work (p = 0.026), consumer and social interactions (p = 0.01) and emotional re-action to vision loss (p = 0.018) was reported in
subjects with DME.

Conclusion: This study has identified possible demographic, medical and visual risk factors of DR and DME in South African diabetic patients.