Role of circulating TNF–a levels in diabetic patients and association with presence and severity of diabetic retinopathy.

Abstract

Abstract: : Purpose: To evaluate a possible association between serum TNF–a levels and the presence and severity of diabetic retinopathy, and non–ocular complications of diabetes. Methods: Serum levels of TNF–a were measured by means of ELISA in a total of 114 subjects; 80 patients with diabetic retinopathy (DR), 18 diabetic patients without DR, and 16 normal, age and sex–matched subjects. Diabetic retinopathy was assesed by fundoscopy and fluorescein angiography. Diabetic retinopathy patients were grouped according to the findings of the more severely affected eye as: non–proliferative, proliferative , and "burnt–out", while the presence of CSME was noted. Diabetic status and systemic complications were evaluated clinically and with laboratory investigations. Results: The presence of diabetic retinopathy was associated with significantly higher TNF–a levels (p=0.001), while the presence of other systemic complications of diabetes (nephropathy, neuropathy, macroangiopathy) were not. With regard to severity of diabetic retinopathy, there were no significant differences in TNF–a serum levels between the three groups. The presence of clinically significant macular edema was not associated with statistically significant differences in TNF–a levels. Conclusions: Although diabetic retinopathy was associated with increased circulating levels of TNF–a in this patient cohort, severity of retinopathy and presence of clinically significant macular edema did not seem to affect TNF–a levels. Non–ocular complications of diabetes did not show an association with circulating TNF–a.

Keywords: diabetic retinopathy • retina • inflammation