Prevalence of diabetic retinopathy in patients with type 1 diabetes mellitus.

OBJECTIVES

Diabetic retinopathy (DR) is the leading cause of legal blindness in young adults. Scarce data from Brazilian subjects with type 1 diabetes mellitus (DM) are available.

AIMS

The objectives of this study were to determine the prevalence of DR and its risk factors in type 1 diabetes mellitus (DM) outpatients from a general hospital.

METHODS

A cross-sectional study of 437 type 1 DM (50.3% males, 82.4% whites) was conducted. DR was graded as absent, mild and moderate non-proliferative DR (mild/moderate NPDR) or severe non-proliferative and proliferative DR (advanced DR). Presence of clinically significant macular edema (CSME) was also recorded.

RESULTS

Any DR was present in 44.4% of subjects. In multivariate analysis, DM duration, systolic blood pressure (SBP) and A1C test were associated with mild/moderate NPDR (P<0.005). Advanced DR, was associated with DM duration, SBP, smoking [odds ratio (OR) 2.75, 95%CI 1.15-6.60] and micro-or macroalbuminuria (OR 8.53, 95%CI 3.81-18.05). CSME was present in 21 (9.4%) patients and was associated with smoking (OR 3.19, 95%CI 1.24-8.2). Its frequency increased with the severity of DR (16.4% in advanced DR, 9.6% in mild/moderate NPDR, and 4.7% in the group without DR; P = 0.020).

CONCLUSION

Patients with type 1 DM attending an endocrine out-patient clinic at a general hospital had a high prevalence of DR associated with traditional risk-factors and smoking.