Abstract: Objective To observe and compare the nerve growth factor (NGF) mRNA expression and the corneal nerve injury and recovery in the rabbit cornea after LASIK and after LASEK. Design Animal experiment. Participants Sixty New Zealand white rabbits. Methods The 60 rabbits were randomly divided into six groups randomly, ten rabbits each group, one group was the normal control group, the remaining five groups was the experimental group. In experimental group, LASIK was performed on one eye of each rabbit, and LASEK was performed on the contrast eye. The rabbits were sacrificed at the 1st, 7th day, 1st, 3rd, and 6th month after surgery, and NGF mRNA expression in cornea was detected by Reverse transcription (RT)-polymerizes chain reaction (PCR). Corneal nerves were stained with the gold chloride staining method. The changes in corneal nerve injury and recovery after LASIK and LASEK were observed with microscope. Main Outcome Measures The changes in corneal nerve injury and recovery under microscope， the expression of NGF mRNA in rabbits’ cornea after LASIK and LASEK. Results  By microscopy observation, at the first day after LASEK, deep matrix nerve was preserved. The neural cutting ends began to regenerate at the seventh day. And at the sixth months, shallow matrix plexus reconstruction completed in the cutting zone, morphology closing to normal; while at the first day after LASIK, nerve fiber cutting ends was visible in the stromal layer. At the seventh day, deep matrix neural plexus had no obvious regeneration. At a month after LASIK the regenerated nerve of neural cutting ends increased in the corneal flap edge, and after six months, shallow matrix plexus of corneal flap began to recover, part of the neural cutting ends had no nerve regeneration, formed the blinds. NGF mRNA expression increased at early period (1, 7 days) after LASEK （0.650±0.101、0.580±0.109）, while at one month after LASIK（0.661±0.032）. The difference of NGF mRNA expression between two groups was smaller with the time of corneal nerve recovery prolonged after surgery（t=0.687，0.277，0.107；P=0.530，0.796，0.920）. Conclusion Compared with LASIK, rabbit corneal nerves are damaged more slightly and recovered faster after LASEK.

Key words: rabbit, LASIK, LASEK, nerve regeneration, gold chloride staining, nerve growth factors