Correlation of Albuminuria and Diabetic Retinopathy in Type-II Diabetes Mellitus Patients

Background: Diabetic ocular disease is a leading cause of blindness today. The most common microvascular complications of diabetes are diabetic retinopathy and diabetic nephropathy. Multiple risk factors like the duration of the disease, age of the patient, high blood pressure, pregnancy, blood glucose control, and nephropathy have been studied to be associated with the development and progression of diabetic microangiopathy. However, the association of albuminuria has still not been studied in detail, especially in type-II diabetes mellitus. Aim: The primary objective of our study is to quantify the relationship between diabetic retinopathy and urine albumin excretion and to correlate the urinary albumin excretion (normoalbuminuria, microalbuminuria, macroalbuminuria) with the severity and grade (mild, moderate, severe non-proliferative diabetic retinopathy [NPDR] or proliferative diabetic retinopathy [PDR]) of diabetic retinopathy. Methods: In this cross-sectional study, 250 patients with type-II diabetes above 40 years of age attending the ophthalmic outpatient department (OPD), Kalinga Institute of Medical Sciences (KIMS), Bhubaneswar in India between September 2019 and September 2021 were subjected to a detailed evaluation of history and a thorough ocular examination. Besides, a blood sugar estimation and urine albumin levels were documented. The grade of diabetic retinopathy was correlated with albumin levels. Results: The duration of diagnosis of diabetes ranged from 1-25 years. The association between the grade of diabetic retinopathy and the duration since diagnosis was significant. Sixty-nine percent of the cases were hypertensives, and 66.7% of hypertensives had diabetic retinopathy. In patients without retinopathy, 83.03% had normoalbuminuria levels, and 16.96% had microalbuminuria. In the mild NPDR group, 37.94% of cases had normoalbuminuria, and 62.06% had microalbuminuria. In the moderate NPDR group, 11.1% of cases had normoalbuminuria, and 88.8% had microalbuminuria. In the severe NPDR group, 57.14% of cases had microalbuminuria, while 42.86% had macroalbuminuria. In the very severe NPDR group, 42.86% of cases had microalbuminuria, and 57.14% had macroalbuminuria. In the PDR group, only 6.6% of cases had microalbuminuria, and the rest, 93.3%, had macroalbuminuria. Conclusion: This study concluded that there is a definite association between albuminuria and severe diabetic retinopathy in type-II diabetes. Microalbuminuria was a finding associated with all grades of retinopathy with skewing towards the lower grades of diabetic retinopathy; a proportion of diabetics without retinopathy also had microalbuminuria, while macroalbuminuria was associated only with those patients who had either severe NPDR, very severe NPDR, or PDR.