Prognostic Value of Proteolysis Indexes in the Formation of Diabetic Retinopathy

Abstract

The article presents the results of the study on the violations in the proteolysis system of patients with type 2 diabetes mellitus (DM) and diabetic retinopathy (DR). We have evaluated the levels of matrix metalloproteinase‑9 (MMP‑9) and tissue inhibitor of matrix metalloproteinase‑1 (TIMP‑1) in the blood and in the aqueous humor (AH) of patients with type 2 DM by means of immunoenzyme method (Bender Medsystems, Austria). The changes in proteolysis system were detected in patients with DR and type 2 DM, they consisted in the increase in the levels of MMP‑9 and TIMP‑1 in the blood and AH in patients both with no signs of DR and with any its stage, compared to the levels of these parameters in patients without diabetes. It was found that MMP‑9 level in the AH and DM type 2 duration have an impact on the probability of developing diabetic macular edema (DME). At the level of MMP‑9 ≥ 105 ng/ml and duration of type 2 DM ≥ 10 years, the risk of developing DME is 100 %. The probability of proliferative DR in patients with type 2 DM over four years of follow-up is influenced: by the level of MMP‑9 in the AH, stage of DR at baseline and duration of DM type 2. When the level of MMP‑9 is ≥ 100 ng/ml, type 2 DM duration ≥ 10 years and there are no signs of DR at the beginning of the observation, the probability of proliferative DR is 85.9 %.

Keywords

• diabetic retinopathy
• proteolysis system
• metalloproteinase‑9
• tissue inhibitor of matrix metalloproteinase‑1
• aqueous humor.