Patterns of conjunctival and scleral regeneration after intraoperative application of cyclosporin A solution in rabbits with steroid-induced glaucoma

Abstract

Aim. In an in vivo experiment, to study the effect of local intraoperative application of 0.05% cyclosporin A solution on the conjunctival and scleral regeneration after surgery on the rabbit eyes with steroid-induced glaucoma. Materials and methods. At the first stage of the experiment, a model of steroid-induced glaucoma was reproduced for 29 male Californian rabbits by injecting 0.5 ml of a 0.4% solution of dexamethasone subconjunctivally in both eyes once a week for 3 months (12 subconjunctival injections for each rabbit). At the second stage of the experiment, after the development of steroid glaucoma, the rabbits were divided into the main group, consisting of the subgroup «a» ( n = 8) and the subgroup «b» ( n = 8), and the comparison group ( n = 8). All animals were performed a penetrating incision of the conjunctiva and a non-penetrating incision of the sclera of one of the eyes. A hemostatic sponge impregnated with 0.05% cyclosporin А solution was applied to the intervention area in the main group, in the subgroup «a» – for 3 minutes, in the subgroup «b» – for 6 minutes. In the comparison group, the cytostatic was not used. Results. The use of 0.05% cyclosporin А solution led to a decrease in the infiltration of fibroblasts and inflammatory cells into the area of surgical injury. On the 4th day after the surgery, cell density in the intervention area in the subgroup «a» with 3-minute application of cytostatic-antimetabolite solution was 2.7 times lower ( p = 0.043) than in the comparison group, while exceeding the values in the subgroup «b» by 3.2 times ( p = 0.036). The number of fibroblasts in the subgroups «a» and «b» was 3.6 ( p = 0.043) and 12.8 times ( p = 0.031) less than in the comparison group, and a shift in the cellular composition of the infiltrate towards the fibroblastic population occurred only on the 14th day after the surgery. Conclusion . Intraoperative application of 0.05% cyclosporin А solution significantly slows down the course of regeneration, reducing infiltrative inflammation in the intervention area, which prevents excessive scarring.