Effect of insulin-like growth factor-1 on corneal surface ultrastructure and nerve regeneration of rabbit eyes after laser in situ keratomileusis

To explore the effect of insulin-like growth factor-1 (IGF-1) on corneal surface ultrastructure and nerve regeneration in rabbit models after laser in situ keratomileusis (LASIK). Forty-two healthy New Zealand white rabbits were divided into two groups, the IGF-1 group and the control group, and LASIK surgery was performed. The corneal surface ultrastructure was observed by transmission electron microscopy, and the nerve regeneration was evaluated by counting the newly regenerated nerves at 1 d, 1 w, 2 w, 1 m, 3 m and 6 m after surgery. Dry eye parameters, including the Schirmer I test and tear break-up time, were examined at all time points. The examination of corneal ultrastructure showed that the number of corneal epithelial microvilli in the IGF-1 group was significantly higher than that in the normal saline (NS) group except in the second postoperative week (p < 0.05). The observation of corneal nerve regeneration showed that the number of regenerated nerve fibers in the IGF-1 group was higher than the control group at all time points (p < 0.05). The parameters of dry eye were significantly higher in the IGF-1 group compared to the control group at all time points except at 1 d and 6 m after LASIK. IGF-1 can effectively accelerate the early repair of corneal surface ultrastructure and nerve regeneration after LASIK and relieve dry eye symptoms in rabbit eyes.