Role of proteolysis in the development of diabetic retinopathy

The aim of this work is to study the role of disorders in the proteolytic system in concordance to the level of matrix metalloproteinase (MMP- 9) and tissue inhibitor of matrix metalloproteinase (TIMP-1) in the blood and aqueous humour and its role in the development of diabetic retinopathy. Materials and methods. Determination of MMP- 9 and TIMP-1 levels in blood and intraocular fluid by ELISA (Bender Medsystems, Austria) in 154 patients (163 eyes), out of which 112 patients (121 eyes) with the diabetes mellitus type 2 comprised the basic group and 42 patients (42 eyes) in the control group without diabetes with corresponding age and sex. Statistical analysis was performed by biostatistical methods Statistica 7.0 (StatSoft Inc., 2004). Results and discussion. Changes in the proteolytic system were found, which consisted of increased levels of MMP-9 and TIMP-1 in the blood and intraocular fluid both in the absence and presence of diabetic retinopathy, its presence in comparison to the level of these indexes in patients without diabetes. Increased levels of MMP-9 and TIMP-1 in patients with diabetes mellitus type 2 were observed in concordance to the stage of retinopathy: in the proliferativestage the level of these indexes was maximum. Conclusions. Thus, the considerable increase in the levels of MMP-9 and TIMP-1 in blood and intraocular fluid in the patients depended on the stage of diabetic retinopathy with the maximal levels in proleferative diabetic retinopathy.