Association of Lipid Profile with Diabetic Retinopathy- A Comparative Study. -

Diabetic retinopathy (DR) remains a leading cause of visual disability and blindness. It is a major microvascular complication of diabetes and is frequently accompanied by lipid exudation. Dyslipidemia leads to development of hard exudates and Clinically Significant Macular Edema (CSME). These, in turn, interfere with vision. The elevated lipid levels are associated with endothelial dysfunction which appears to play an important role in the pathogenesis of Diabetic Retinopathy, particularly in relation to breakdown of blood-retinal barrier. The current study was undertaken to determine the association of serum lipid profile with diabetic retinopathy and its severity. In the present study, 200 patients having type II diabetes mellitus of age group ranging from 45 to 80 years were studied. 100 age and sex matched controls were also studied. The patients were categorized with respect to the presence or absence of diabetic retinopathy. In the group having retinopathy, patients were subcategorized depending on the severity / grade of retinopathy and presence or absence of CSME. All the three groups had a near equal sex distribution with only a slight male predominance. A significant correlation was found between the patient age and diabetic retinopathy. In the present study, the duration since diagnosis of diabetes (diabetic age) ranged from 5 - 25 years. It is found that patients with retinopathy significantly had a longer mean duration of diabetes as compared to those diabetics without retinopathy. Most of the diabetics included in the study had poor glycemic control suggested raised FBS and PPBS levels. The mean values of FBS and PPBS were higher in group 1 (diabetics with diabetic retinopathy) as compared to that in group 2 (diabetics without diabetic retinopathy), reinforcing the fact that the development and progression of DR is influenced by the level of hyperglycemia. The present study showed statistically significant correlation between diabetic retinopathy and raised total cholesterol level (p = 0.016). Hypercholesterolemia was significantly associated with the occurrence of diabetic retinopathy and CSME. Mean serum total cholesterol concentrations were higher in subjects with severe NPDR, very severe NPDR and PDR as compared with subjects without DR (p=0.046). No correlation was found between diabetic retinopathy and visual acuity. Thus, this study reinforces the observation that there is a strong association between dyslipidemia and diabetic retinopathy including CSME.