Association of HBA1c and Plasma Glucose Levels with Diabetic Retinopathy.

Background Diabetic retinopathy is one of the leading causes of blindness worldwide. The relationship between glucose level and development of diabetic retinopathy has always been an area of interest and constantly evolving. Objective To determine the association of glycosylated hemoglobin and plasma glucose levels with different grades of diabetic retinopathy. Method A hospital based cross sectional study was conducted among 504 patients with type II diabetes mellitus attending the Department of Ophthalmology in a University Hospital for one year duration. Relevant history regarding diabetes mellitus was recorded for all patients. The status of diabetic retinopathy in each patient was diagnosed by detailed ophthalmological examination and classified according to International Classification of Diabetic Retinopathy Scale. All the patients were evaluated for their glycosylated hemoglobin, fasting and post prandial blood glucose levels. Bivariate analysis using t-tests and chi-square tests was used to measure the strength of association between the different variables. An Analysis of Variance (ANOVA) test was used to evaluate the association between the means of different variables. Result Total 504 patients constituted of 254 males (50.39%) and 250 (49.60 %) females. Almost half of the study population had poor glycemic control and deranged fasting and post prandial blood sugar levels. Diabetic retinopathy was observed in 124 (24.60%) patients and diabetic macular edema was observed in 42 (8.33%) patients. Poor control of glycosylated hemoglobin (> 7.6) was seen in 88 (70.96%) cases of diabetic retinopathy and 34 (80.95%) cases of diabetic macular edema. Uncontrolled fasting and postprandial blood sugar levels were associated with a significant number of cases of diabetic retinopathy and of diabetic macular edema respectively. A statistically significant association was observed between increasing grades of diabetic retinopathy and higher glycosylated hemoglobin and plasma glucose levels. Conclusion Higher the level of glycosylated hemoglobin and plasma glucose levels, more severe is the grade of diabetic retinopathy.