Experimental substantiation of scleral crosslinking

Purpose. To substantiate the efficacy and safety of scleral collagen cross-linking with riboflavin and ultraviolet radiation. Material and methods. The study was conducted on cadaver porcine eyes and rabbit eyes. Results. It has been experimentally proven that crosslinking with riboflavin / ultraviolet A leads to an increase in the biomechanical strength of the scleral tissue, changing its structure and leading to an increase in the packing density of collagen fibers and an increase in the diameter of collagen fibrils, which confirms the formation of additional cross-links between scleral macromolecules. The absence of any pathological changes in the fibers of the fibrous membrane of the eye was established. The permeability of scleral tissue for ultraviolet radiation of the A range was determined. Based on the data obtained, a formula was proposed for calculating the threshold value of the intensity of ultraviolet radiation during the SCXL procedure. Using the methods of light microscopy, electroretinography and optical coherence tomography, it was revealed that SCXL with riboflavin / ultraviolet A under the studied parameters is safe for the structures of the eye (cornea, retina and optic nerve). A gentle technology for photopolymerization of the sclera with the use of the “UFalink S” device has been developed, the advantage of which is the ability to carry out ultraviolet irradiation in hard-to-reach areas of the eyeball. At the same time, an effective increase in the biomechanical strength characteristics of the scleral tissue was proved and the absence of a damaging effect on the structures of the eye was demonstrated. Conclusion. A clinical study of the scleral crosslinking procedure with riboflavin / ultraviolet A with the proposed parameters: irradiance of 3 mW / cm², irradiation time 30 minutes and preliminary saturation of the sclera with 0.1% aqueous solution of riboflavin for 20 minutes, which in experiments have shown their effectiveness and safety, is recommended. During the procedure, it is recommended to use a water-based photosensitizer riboflavin, without the addition of dextran, which leads to dehydration of the sclera and an increase in its permeability to ultraviolet light, which increases the risk of damage to the inner layers of the eye. Key words: scleral crosslinking, ultraviolet A, riboflavin, experiment, myopia.