Corneal Endothelial F-actin Changes after Deep Photorefractive Keratectomy(PRK) in Rabbit

ABSTRACT

Laser-assisted in situ keratomileusis(LASIK) theoretically provide less corneal haze and more accurate correction. In the LASIK. however, photo refractive keratectomy(PRK) will be done on the stromal surface exposed after removal of the 130 micrometer thick lenticule. Deep stromal ablation after removal of 130 micrometer thick lenticule may result in endothelial damage. We observed endothelial cytoskeletal changes after deep PRK to evaluate the endothelial safety in rabbit. PRK was performed on the rabbit cornea without removing the epithelium with VISX 20/20 (160mj/cm2/pulse, 5Hz) to correct 6, 9, 12, and 15 diopters of myopia by single or multiple zone. Seven days after ablation, the rabbit was euthanized, corneas excised and endothelial F-actin was stained with NBD-phallacidin to demonstrate any cytoskeletal changes. No F-actin changes were observed in corneas after either single zone, 6 or 9 diopter correction, and multiple zone ablation. However, 12 diopters or higher correction in a single zone resulted in pleomorphism and polymegethism on focal areas. In the LASIK procedure, the endothelium might be damaged and further investigation for the endothelial preservation during the procedure is needed in human.