Βιοχημική διερεύνηση της παθοβιολογίας του αποφολιδωτικού συνδρόμου των οφθαλμών ; Biochemical investigation of the pathobiology of exfoliation syndrome of the eye

Exfoliation syndrome (XFS) is a pathological condition characterized by the synthesis and deposition of thin, white, grainy material upon and within ocular and extraocular tissues. It is thought, nowadays, to be the most common identifiable condition leading to the development of exfoliation glaucoma (XFG) and blindness. XFS is an age-related, generalised disorder of extracellular matrix, due to excessive synthesis and defective degredation of matrix components. Oxidative stress is involved in the development of XFS. The study of certain factors that are related to oxidative stress, as ultraviolet radiation, growth factors, endothelines, metalloproteases etc., can provide important information on the investigation of the pathophysiology of the disorder and the discovery of effective measures for its prevention and treatment. For our studies we used aqueous humour samples from patients with XFS and patients with cataract (controls) from the Department of Ophthalmology, AHEPA, and trabecular meshwork cells samples from cornea transplantation parts from the AHEPA eye bank. We used the following methods: i) enzyme-assays and immune-assays, ii) zymography, iii) cell cultures. Our findings indicate the involvement of gelatinases in the pathogenesis of XFS. These enzymes may change the compositition of extracellular matrix. We observed that the total gelatinolytic activity is reduced and that the total concentration of MMP2 is elevated in the aqueous humour of patients with XFS compared to controls. On the other hand there was no statistically significant difference in the total concentration of MMP9 between the two groups. Afterwards, we studied gelatinases by zymography, discovering changes in the levels of the pro-forms and the active forms of the enzymes. All four types of the enzymes were detected in the aqueous humour of patients with XFS and controls. We observed a reduction in both forms of MMP2 (pro-form and active) and also in active MMP9, a fact that can explain the reduction of the total gelatinolytic ...