The early cellular reaction of eye tissues to the implantation of bioresorbable drainages saturated by immunosuppressants with a selective mechanism of action

Prolonged use of immunosuppressants with a selective mechanism of action is a promising strategy in the prevention of postoperative scarring in glaucoma surgery. In order to assess the cellular response of eye tissues to the implantation of bioresorbable drains saturated with cyclosporin A or everolimus, a filter-type hypotensive operation with implantation of polylactide-based drains was simulated in 12 rabbits. Drainages implanted in rabbits of the two experimental groups under study were pre-saturated with either cyclosporin A or everolimus. The control group consisted of animals that were implanted with drains not saturated with any drugs. On the 7th day after the operation, the animals were taken out of the experiment, the eyeballs were enucleated, and histological preparations stained with hematoxylin and eosin, as well as hematoxylin and Picrosirius-red were prepared. Using a score on a scale from 0 to 5, the cellular composition within the drainage material, the intensity of collagen synthesis in the drainage, the thickness of the capsule around the drainage, and the number of blood vessels were analyzed. In comparison with the control group, the study groups showed a significantly lower amount of mononuclear cells, fibroblasts and giant cells of foreign bodies, as well as a lower thickness of the capsules surrounding the drainage, up to their complete absence. In addition, the intensity of collagen synthesis inside the drainage material of the studied groups was significantly lower. The drains of the everolimus group were characterized by an extremely low density of viable cellular elements inside the implanted material and a complete absence of collagen. At the same time, no toxic effect of the substance on the surrounding tissues was found. Thus, the saturation of bioresorbable drainages based on polylactide with cyclosporin A and everolimus contributed to a decrease in the intensity of the formation of connective tissue elements both inside and around the drainage in the early postoperative period.