Study of Correlation between Renal Function Test and Severity of Diabetic Retinopathy in Patients with Type 2 Diabetes Mellitus

Abstract

BACKGROUND Retinopathy and nephropathy are chronic vascular complications of type 2 diabetes mellitus, this eventually leads to end stage renal disease and blindness. Diabetic retinopathy is an important cause of legal blindness in 20 - 70 years. The purpose of the study was to establish association between severity of diabetic retinopathy with systemic levels of glycosylated haemoglobin and renal function test. METHODS This is a cross sectional study conducted among 75 patients with type 2 diabetes mellitus attending the ophthalmology out-patient department (OPD) of Acharya Vinoba Bhave Hospital, Wardha and patients referred from the hospital. Detailed fundus examination and staging of diabetic retinopathy (DR) was done. Glycosylated haemoglobin levels, serum creatinine and blood urea nitrogen were measured. RESULTS Majority of patients were in the age range of 61 to 70 years. Mean ± SD of 3 parameters in patients with no DR, mild non-proliferative diabetic retinopathy (NPDR), moderate NPDR, severe NPDR and proliferative diabetic retinopathy (PDR) were as follows: Serum creatinine 1.12 ± 0.41, 1.21 ± 0.53, 1.35 ± 0.49, 1.55 ± 0.22 and 1.70 ± 0.23 respectively. P = 0.007. Blood urea nitrogen (BUN) 28.62 ± 4.20, 31.83 ± 7.20, 37.31 ± 12.57, 44.21 ± 7.53 and 48.76 ± 5.08 respectively. P = 0.0001. HbA1c l, 6.72 ± 0.60, 8.14 ± 0.98, 8.52 ± 2.67, 9.96 ± 1.22 and 12.14 ± 1.96 respectively. P = 0.0001. All the 3 parameters were statistically significant. 40 % of cases had clinically significant macular oedema. CONCLUSIONS Poor glycaemic control as seen by higher levels of glycosylated haemoglobin and deranged renal function is associated with severe form of DR. KEY WORDS Diabetes Mellitus, Diabetic Retinopathy, Serum Creatinine HbA1c and BUN