Role of matrix metalloproteinase 9 and its tissue inhibitor 1 in development and prognosis of diabetic retinopathy.

The article presents the results of investigation of violations in the proteolysis system in patients with type 2 diabetes and diabetic retinopathy (DR). We studied the levels of matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of matrix metalloproteinase-I (TIMP-1) in the blood and in the intraocularfluid ofpatients with type 2 diabetes depending upon the stage of DR. We have established that the level of MMP-9 and TIMP- in the blood and in the intraocular fluid increased in patients with type 2 diabetes without signs of DR and with any stage of DR compared to the levels of these parameters in patients without diabetes. Increasing the levels of MMP-9 and TIMP-J took place with increasing of DR severity and reached its maximum levels at the proliferative stage of DR. It was found that the levels of MMP-9 in the intraocular fluid and type 2 diabetes duration affected theprobability of developing diabetic macular edema. At the level of MMP-9 105 ng/ml and 2 diabetes duration 10 years, the probability of developing macular edema was 100%. As a result of the construction ofpredictive models it was found that the level of MMP-9 in the intraocular fluid, stage of DR at the beginning of observation and type 2 diabetes duration had influence on the probability of the development ofproliferative DR over 4 years offollow-up. If the level of MMP-9 100 ng/ml, type 2 diabetes duration 10 years and absence of DR at the beginning of observation were observed the probability of developing proliferative DR would compose 85.9%.