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The goal of the investigation was to study the changes of scleral matrix collagen in progressing primary open-angle glaucoma (POAG). In scleral samples of 16 patients aged 52-81 years with different stages of POAG amino acid composition, collagen content and cross-linking ratio characterizing tissue rigidity were estimated. Collagen I was found to be the dominant type in sclera of glaucomatous and normal eyes, though as POAG progressing the content and cross-linking increase, that underlies the scleral rigidity increase and permeability decrease. Similar ratio of collagen cross-linking with age and glaucoma progression give evidence of specific pathologic changes of the dominant matrix component, that may be one of significant pathogenic factor of POAG.

The paper aims at the evaluation of prospects for using glyceraldehyde as a cross-linking agent for the scleral tissue. Stability parameters (denaturation temperature, Young's modulus, ultimate tensile stress, proteolytic resistance) and analytical parameter (fluorescence intensity) were determined during the glycation process of isolated rabbit sclera. The analysis of fluorescence spectral characteristic provided information about some glycation products. The glyceraldehyde treatment was resulted in a significant increase in thermal stability, proteolytic resistance and improvement of biomechanical characteristics (Young's modulus, ultimate tensile stress). Unique properties of the reaction between scleral collagen and glyceraldehyde are observed at short cross-linking times. The appearance of intermediate collagen fraction with lowest thermal and proteolytic stability was detected.