Risk factors for diabetic retinopathy in Kuwaiti type 2 diabetic patients

OBJECTIVE: To determine the risk factors associated with diabetic retinopathy in Kuwaiti subjects with type 2 diabetes.

METHODS: Kuwaiti subjects with type 2 diabetes (n=165) attending the Diabetic Clinic at Al-Sabah Hospital, Kuwait between October 2000 and March 2005 were screened for diabetic retinopathy.

RESULTS: Any diabetic retinopathy was found in 40% while 20.6% had sight threatening retinopathy. Mild NPDR was present in 21.2%, moderate to severe non-proliferative diabetic retinopathy (NPDR) in 7.9%, and proliferative diabetic retinopathy (PDR) in 3.0%. Maculopathy was present in 10.3% and 7.9% of the patients were photocoagulated. Compared to those without retinopathy, diabetic patients with any retinopathy were significantly older (51.7 ± 10.3 versus 47.2 ± 9.5 years; p<0.005), had longer duration of diabetes (13.1 ± 6.3 versus 4.7 ± 5.4 years; p<0.0001), higher systolic blood pressure (142.9 ± 23.0 versus 130.3 ± 20.2; p<0.0001) and poor glycemic control (Hemoglobin A1c = 10.1 ± 2.4 versus 8.9 ± 2.3; p<0.005). The prevalence of hypertension and nephropathy was significantly higher in patients with any retinopathy than those without retinopathy (70.8% versus 49.5%; p<0.01 and 64.4% versus 30.8%; p<0.0001) respectively. Longer duration of diabetes and presence of nephropathy was the most significant independent factors associated with any retinopathy and sight-threatening retinopathy. Treatment with sulphonylurea or insulin, and poor glycemic control were other significant independent factors associated with any retinopathy.

CONCLUSION: Longer duration of diabetes, presence of nephropathy, glycemic control and mode of treatment were the most significant independent risk factors of diabetic retinopathy. However, a population-based study is warranted to identify the risk factors, as well as the prevalence of diabetic retinopathy.