KERATOCONUS TREATMENT: SOME PHYSICAL PARAMETERS OF DIFFERENT SOLUTIONS FOR CORNEAL CROSS-LINKING

Abstract

Cornea, the primary refractive element of the eye is a clear, transparent and elastic tissue
that acts as a physical barrier between the external environment and the internal ocular
elements. Cornea consists of five layers. Its Stroma layer is rich with proteins especially
with collagen. Collagen is among the most abundant fibrous proteins and fulfils a variety of
mechanical functions. When cross-links between the collagen fibers are weak, cornea will
tend to thin and be deformed. This kind of eye disease is called Keratoconus.
A unique treatment for Keratoconus is called corneal cross-linking (CLX). During the CLX
procedure the cornea is exposed to UV-A light and ribofilavin-dextran solution is instilled
onto the cornea [1]. This treatment works by increasing collagen cross-links in the Stroma
layer. CXL method has some problems which are explained in reference [2].
In this study, temperature and pH level change were examined for different solutions. Nine
different solutions with varying concentrations were prepared by using riboflavin, dextran
and dextrin substances. Behavior of these solutions at different temperatures and
effectiveness of these concentrations according to eye's pH level were investigated. Their
absorption and fluorescence spectrum were also investigated in the critical concentration
%0.1 (w/v) of riboflavin [3]. Their diffusion coefficients were found from the ratio of
luminescence intensities measurement by using Fick’s Diffusion Law.

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