Тhe Safety Assessment of the Ultraviolet Scleral Crosslinking with Riboflavin/UVA in Experiment

The purpose is to evaluate the safety of the scleral crosslinking with riboflavin/ultraviolet A (UVA) in an experiment in vivo. Materials and methods. The study was carried out on 34 Chinchilla rabbits (68 eyes). The right eyes were crosslinked (34 eyes), the left eyes were served as controls (34 eyes). Scleral crosslinking (SCXL) was performed with sclera saturation with a photosensitizer (0.1 % aqueous solution of riboflavin) for 20 minutes and its subsequent irradiation with ultraviolet A (wavelength of 370 ± 5 nm, irradiance — 3 mW/cm2), total exposure time — 30 minutes (6 cycles of 5 minutes). The effect of the procedure on the anatomical and functional state of the eye layers was assessed with high-resolution optical coherent tomography (OCT) and electroretinography (ERG) before crosslinking, a day, 7 and 30 days after it. Results. OCT did not reveal any pathological changes after scleral crosslinking with riboflavin/UVA. The layers of the retina, choroid and sclera were clearly visualized. The performed morphometric analysis has showed the absence of statistically significant changes in the eye layers thickness after ultraviolet crosslinking. The amplitude-time characteristics and the shape of the electroretinogram of the experimental and control rabbits eyes were identical during all periods of observation, had a classic appearance. All waves of ERG were well expressed. It indicates a satisfactory functional state of the retinal neuroreceptor mechanisms. Conclusion. For ultraviolet crosslinking we used UVA with an irradiance of 3 mW/cm2 for 30 minutes and a 0.1 % aqueous solution of riboflavin without dextran and did not reveal any side effects of the procedure. Thus, scleral crosslinking with these parameters is safe for the eye layers in an experiment in vivo.