Effect of crosslinking with riboflavin and ultraviolet a (UVA) on the scleral tissue structure

Aim. To evaluate the effect of scleral crosslinking with riboflavin and ultraviolet A (UVA) on scleral tissue structure in vitro. Material and methods. The study was performed on seven porcine cadaver eyes. Two parallel scleral strips were excised from each eyeball; one was subjected to the crosslinking procedure (instillation of 0.1% aqueous solution of riboflavin mononucleotide for 20 min followed by UV irradiation of 3 mW/cm2 for 30 min), and the other was used as control. Scleral structure was evaluated using light (Van Giesons stain) and electron microscopy. Special software was used to perform morphometric analysis of the microphotographs. Results. As a result of crosslinking, the average packing density of collagen fibers increased by 8.2%, the intermediate space decreased by 5.2%, and the average diameter of collagen fibrils increased by 12%. There were no pathological changes in the scleral structures. Conclusion. Obtained results confirm the efficacy of scleral crosslinking with riboflavin/UVA in forming additional crosslinks and the safety of the procedure for the scleral tissue.