AIM:To contrast analysis of postoperative variation of corneal posterior surface heights after Femtosecond LASIK(FS-LASIK)and small incision lenticule extraction(SMILE)for high myopia.

METHODS: Sixty-seven cases of high myopic patients(132 eyes)operated with laser corneal refractive in our hospital from May to Dec. in 2015(-6.00D≤spherical equivalent degree≤-10.00D)were selected and divided into FS-LASIK group and SMILE group. The thickness of corneal flaps at FS-LASIK and the thickness of map at SMILE were designed to be 110μm. Corneal posterior surface heights were examined by Pentacam at preoperation, postoperative 3 and 6mo after FS-LASIK and SMILE operation. Surface height changes after preoperative, postoperative 3 and 6mo were compared by measuring Pentacam corneal analysis system.

RESULTS: Six months after operation, the FS-LASIK posterior corneal surface height was 6.47±1.65mm, significantly higher than 5.20±1.32mm before operation. SMILE posterior corneal surface height was 6.40±1.33mm, significantly higher than 5.18±1.25mm before operation, the differences were statistically significant(P<0.05). Six month after surgery, two methods of corneal surface height variation obtained was 1.29±1.28mm and 1.22±0.89mm, there was no significant difference(P>0.05).

CONCLUSION: After FS-LASIK and SMILE, the corneal posterior surface is protrusive. FS-LASIK is slightly obvious than SMILE in early period. The stability of the posterior surface is better after SMILE.