Abstract
Purpose: :
To assess the influence of methylglyoxal (MGO) on in vitro corneal permeability, hydraulic conductivity (K) and non-enzymatic crosslinking properties.
Methods: :
Cornea obtained from porcine eyes was used throughout this study. Samples were weighed and their thickness were measured, and then incubated in PBS, 0.5% MGO or 2% MGO for 24 hours. Treated cornea was mounted onto a two-chamber diffusion apparatus to determine permeability and K. Permeability across the tissue, characterized by means of a permeability coefficient, was measured by using fluorescence spectrometry to determine the diffusion of sodium fluorescein. In the flow study, the apparatus was connected to a water column and the descent of water was measured to determine K. Treated samples that weighed 10-25mg were used for papain digestion for the detection of crosslinking density. Corneal pieces were incubated in a digestion buffer at 60°C for 24 hours and the supernatant was removed and used to perform fluorescence assays.
Results: :
Corneal tissue showed a trend of decreasing permeability with increasing MGO treatment. Similarly, MGO treated samples showed a trend of decreasing K compared to controls. In preliminary studies, no statistical significance was found between control and MGO samples and between the two MGO samples. There is a statistically significant linear correlation (P <0.001), however, between increased MGO treatment and fluorescence detection in the digested samples. Fluorescence is an indication of non-enzymatic crosslinking.
Conclusions: :
Corneal samples showed a trend of decreasing permeability and hydraulic conductivity while non-enzymatic crosslinking properties increased with increasing treatment with MGO. Future experiments will look at whether varying the concentration and treatment time of MGO can further modulate the mechanical and crosslinking properties of corneal tissue.
Keywords: cornea: basic science