[Comparison of corneal wound healing of photorefractive keratectomy and laser in situ keratomileusis in XXXX ].

@entity267 @entity11504 @entity95 @entity2543 @entity14100 @entity1714
OBJECTIVE: To compare effects of photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) on the @entity267 and corneal wound healing and to investigate the possible mechanism of corneal haze and myopic regression histopathologically. METHODS: Twenty-four New Zealand white @entity95 were allocated randomly to correct -4.00 and -8.00 diopters and were operated with PRK on right eyes and LASIK on left eyes. At 10 days and 1, 3, and 6 months, corneal haze was observed, refraction was evaluated, and 3 @entity95 were randomly selected for each time point to be enucleated, and corneas to be bisected. One half of each @entity267 was evaluated using transmission electron microscopy, and the other half was evaluated using either light microscopy or immunohistochemical staining for collagen type III, IV, @entity11504 ( @entity11504 ) and @entity14100 ( @entity14100 ). RESULTS: Different degrees of corneal haze and myopic regression were observed after PRK: the higher the desired myopic correction, the heavier the haze. Corneal wound healing response was greater and lasted longer after PRK than after LASIK. Various pathological findings such as @entity2543 , basal membrane reforming and extracellular matrix deposits were found in the ablation zone and repair mechanisms were still active at 6 months after PRK. Whereas after LASIK, the interface between the flap and stromal bed was transparent except for growing epithelial plugs and lightly proliferating stroma coinciding with the flap margins. After both PRK and LASIK, all corneal cell types were consistently positive for @entity14100 antibody during the corneal wound healing time. @entity14100 antibody positivity decreased as the wound healing approached completion. The histopathological changes of corneal haze and myopic regression are as follows: @entity2543 , basal membrane immaturity, anterior stromal keratocyte increase and activity, new collagen III production and irregular arrangement thereof, and @entity11504 deposition in the extracellular matrix under the epithelium. CONCLUSIONS: Compared with PRK, LASIK ensures refractive stability with quick wound healing and minimal tissue proliferation resulting in a more promising corneal refractive surgery to correct @entity1714 , especially more severe cases of @entity1714 . The corneal wound healing especially the stromal healing is the key to the cause of haze and myopic regression. @entity14100 may be involved in scar formation during wound healing by stimulating expression of collagen III and @entity11504 and is believed to be an important regulating factor.
