Comparison of visual quality after Femto-LASIK and TransPRK in patients with low and moderate myopia

Purpose: To compare the visual quality after surgery of femtosecond-assisted laser in situ keratomileusis (Femto-LASIK) and transepithelial photorefractive keratectomy (TransPRK) in low and moderate myopia patients.

Methods: A prospective controlled study was performed on 114 eyes of 62 patients with low to moderate myopia, including 64 eyes of 36 cases in Femto-LASIK group and 50 eyes of 26 cases in TransPRK group. The uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), residual spherical equivalent (SE), wavefront aberration and contrast sensitivity were examined and analyses preoperatively, 1 month and 3 months postoperatively.

Results: The UCVA over 0.8 was 100% in two groups at 1 month and 3 months postoperatively. Femto-LASIK group (96.49%) had a higher percentage than TransPRK group (67.39%) of UCVA over 1.0 at 1 month postoperatively (p < 0.001), but it was similar in two groups (97.78%, 90.48%) at 3 months postoperatively (p = 0.15). Femto-LASIK group (77.19%, 86.67%) had a higher percentage than TransPRK group (30.43%, 52.38%) of UCVA over 1.2 at 1 month and 3 months postoperatively (p < 0.001, p = 0.001). The SE of Femto-LASIK group was 0.07 ± 0.21 D, 0.02 ± 0.23 D at 1 month and 3 months postoperatively, and of TransPRK group was 0.11 ± 0.31 D, 0.14 ± 0.38 D; two groups had no significant differences (p = 0.57, p = 0.08). The safety index was 2.0 in Femto-LASIK group and 1.6 in TransPRK, while the efficacy index was 1.67 and 0.4, respectively. The vertical coma, spherical and higher-order aberrations of Femto-LASIK group were 0.37 ± 0.54 μm, 0.31 ± 0.27 μm, 0.89 ± 0.49 μm at 1 month postoperatively, and of TransPRK group were 0.12 ± 0.38 μm, 0.14 ± 0.28 μm, 0.71 ± 0.26 μm. There was significant difference between two groups at 1 months postoperatively (p < 0.001, p = 0.001, p = 0.006), but no significant difference at 3 months (p > 0.05). The contrast sensitivity without glare in 18 c/d spatial frequencies of Femto-LASIK group was 1.08 ± 0.26 at 1 month postoperatively, and that in TransPRK group was 0.99 ± 0.22. There was significant difference between two groups (p = 0.02). The contrast sensitivity with glare in 12 c/d and 18 c/d spatial frequencies at 1 month postoperatively had significant differences between Femto-LASIK and TransPRK groups (1.52 ± 0.17, 1.10 ± 0.23 vs 1.38 ± 0.39, 1.00 ± 0.27, p = 0.02, p = 0.03). While there were no significant differences at 3 months postoperatively (p > 0.05).

Conclusion: Femto-LASIK had a higher increase in whole eye higher-order aberrations and contrast sensitivity than TransPRK at 1 month postoperatively, but they were similar at 3 months postoperatively in low and moderate myopia patients.