Regenerative effects of immobilized hyaluronidase and subtilisin enzymes on experimental models of chemical and mechanical corneal trauma

Abstract

Purpose: to study the regenerative potential of immobilized hyaluronidase and subtilisin enzymes preparations in experimental models of chemical and mechanical corneal trauma.Material and methods. The study involved 28 mongrel rabbits weighing 3.5 to 4 kg, divided into 4 groups for separate studies of repair models according to different types of injury (chemical vs. mechanical), and different drugs and the methods of administration thereof. Hyaluronidase (PEG-hyaluronidase) and subtilisin (PEG-subtilisin) pegylated by electron beam synthesis technology were used. The condition of the cornea was assessed 24 hours after the injury had been inflicted, whereupon the eyes were enucleated and histologically examined.Results. The chemical trauma groups treated by PEG-hyaluronidase revealed a decrease in the wound area by an average of 36.6 mm2, while those given a subconjunctival injection showed a 36.08 mm2 decrease. If PEG-subtilisin was applied, the area of the corneal defect revealed an average increase of 11.63 mm2 (with a case of perforation registered). In subconjunctival injection of PEG-subtilisin, the wound area decreased by 27.42 mm2. In the mechanical trauma groups, a similar pattern was observed: with the instillation of PEG-subtilisin, the wound area averaged 53.63 mm2 and 1 case of perforation was registered, whilst with subconjunctival administration, the wound area decreased to 28.76 mm2. With PEG-hyaluronidase instillations, a significant wound area decrease of 36 mm2 was noted, and with subconjunctival administration, the wound area decreased by 70.3%. A higher corneal transparency in the optical zone and a weaker inflammatory reaction with the use of PEG hyaluronidase were revealed by histological testing.Conclusion. A positive effect of PEG-hyaluronidase, specifically concerning the enhancement of regenerative processes in the wound in chemical and mechanical wounds could be seen. PEG-subtilisin showed no positive effects, which may be associated with high fibrinolytic activity.