[Evaluation of selected parameters of collagen metabolism in patients with myopia]

Myopia is a common condition of vision deprivation characterized by the excessive lengthening of the eye axis. There are hypotheses that the elongation of the eye is connected with the connective tissue disorder in which the scleral collagens are inappropriately remodelled. The most common type of collagen and the first to be discovered is type I and it is the dominating one in cornea and sclera. Type III is always found in coexistence with type I.

The aim of the study was to evaluate the serum concentration of carboxyterminal propeptyde of procollagen type I (P I CP), aminoterminal propeptyde of procollagen type III (P III NP) (markers of collagen synthesis) and carboxyterminal telopeptyde of collagen type I (I CTP) (marker of collagen disintegration) as markers of the connective tissue metabolism in patients with myopia.

Serum concentration of P I CP, P III NP and I CTP were studied in 25 (15 female and 10 male) patients with myopia and in 15 emmetropic subjects using the RIA method (Orion Diagnostica).

The serum concentration of P I CP and P III NP increased significantly in patients with myopia when compared with the control group. There was no significant difference in the concentration of both of them among patients with various degrees of myopia, although the concentration of P I CP and P III NP increased with the increase of myopia. The was no statistical difference in the concentration of I CTP in low and medium myopia but we found increased concentration of I CTP in high myopia comparing with control group.

The mechanical properties as well as the increased remodelling of the collagen could be some of the factors involved in myopia pathogenesis. Changes in the collagen metabolism concern not only the eye tissue, but probably also disorders of the systemic connective tissue turnover.