Western blot analysis of types Ⅰ, Ⅲ, Ⅴ, and Ⅵ collagens after LASEK and PRK in cornea of rabbits and the significance / 第三军医大学学报

ABSTRACT

Objective To observe and compare the accurate dynamic changes of types Ⅰ, Ⅲ, Ⅴ, and Ⅵ collagens in the wound healing processes of the rabbit cornea undergoing laser epithelial keratomileusis (LASEK) or photorefractive keratectomy (PRK) and to investigate the possible mechanisms of corneal haze and myopic regression. Methods New Zealand White rabbits were divided into 8 groups normal control group (n=6), 1, 7 d, and 1, 3, 4, 5, and 6 month groups (n=14). Every rabbit underwent LASEK in one eye while the other one with PRK. We used Western blot analysis to compare the wound healing process of dynamic changes of types Ⅰ, Ⅲ, Ⅴ, and Ⅵ collagens in the rabbit cornea at every time point. The results were analyzed with data analysis software. Results Western blot analysis showed that after LASEK, the cornea wound healing with types Ⅰand Ⅲ collagens were much faster than that of PRK, and the wound response was also much weaker. Whereas for types Ⅴ and Ⅵ collagens, their dynamic changes were similar between LASEK and PRK, and they both reached the peak value at 3 month after the surgery, but LASEK group returned to normal earlier than PRK group. The value of these two types of collagens after PRK was higher than that by LASEK. The changes of these four types of collagens may offer us at least partial explanation to the difference of formation of corneal haze and refractive regression. Conclusion There are significant differences between LASEK and PRK in types Ⅰ, Ⅲ, Ⅴ, and Ⅵ collagens or the time of reacting, reaching apex, and returning to normal. LASEK has slighter intensity of reaction. The results indicate that there is excessive aggradation of collagens after PRK, which may be the histological foundation of obvious haze and myopia regression.