AIM: To compare the difference of biomechanical stability after a femtosecond laser-assisted in situ keratomileusis(FS-LASIK)and laser-assisted subepithelial keratomileusis(LASEK)by ocular response analyzer(ORA).

METHODS: This prospective study was conducted at the First Affiliated Hospital of Harbin Medical University, and myopic patients with the equivalent sphere between -2.00 and -5.00 diopters from January 2016 and December 2017 were enrolled. All the subjects were divided into FS-LASIK and LASEK group respectively according to different surgical methods. There were 64 patients(100 eyes)participated in the FS-LASIK group while 53 patients(100 eyes)in the LASEK surgery group. Corneal hysteresis value(CH)and corneal resistance factor value(CRF)were measured pre-, 1mo and 3mo postoperation of all the subjects. And the variance analysis of two groups was repeated to compare the overall difference between the two modes of operation from pre-operation to post operation.

RESULTS: The CH and CRF value of the two groups were different before and after operation(P<0.05). The comparison results of repeated measurements showed that the CH value and CRF value of the surgical methods were reduced in 1 and 3mo after operation, respectively, and there was significance(P<0.05). The CH and CRF of FS-LASIK group was lower than LASEK group only in 1mo after the operation(P<0.05).

CONCLUSION: Both surgeries could affect the biomechanical stability of cornea. From the point of view of biomechanical stability, LASEK operation is safer than FS-LASIK operation and reduces the possibility of postoperative refractive regression.