Comparison Of Transepithelial Photorefractive Keratectomy And Femtosecond Laser Small-Incision Lenticule Extraction In Low To Moderate Myopia

To compare the effectiveness, safety, stability and predictability of Transepithelial Photorefractive Keratectomy (Trans-PRK) and Small-Incision Lenticule Extraction(SMILE) for low to moderate myopia.

Retrospective analysis and study. The medical records of 143 patients with trans-PRK surgery or SMILE surgery from January 2019 to February 2019 and with complete half-year follow-up data were included. Of these, 72 patients(139 eyes) received Trans-PRK and 71 patients(140 eyes) received SMILE.

 The preoperative and postoperative best corrected visual acuity (BCVA) and postoperative uncorrected vision (UCVA) were recorded by decimal visual acuity. Compare postoperative effectiveness index, safety index, stability and predictability of the two groups. The effectiveness index is the ratio of postoperative UCVA to preoperative BCVA; the safety index is the ratio of postoperative BCVA to preoperative BCVA;the stability is the difference between equivalent spherical diopter at 3 and 6 months after surgery; and the predictability is the ratio of eyes within ±0.5D at 3 and 6 months after surgery.

Three months after the surgery, The number of eyes with equivalent spherical diopter within±0.5D in the trans-PRK vs. SMILE groups was 66.7% and 73.7%, respectively, There was no significant difference (c²=0.321, P=0.571); Six months after the surgery, The effectiveness index of the Trans-PRK and SMILE groups were 1.22±0.17 and 1.17±0.18, respectively, There was no significant difference (t=-1.267, P=0.209); The safety index of the two groups were 1.07±0.13 and 1.05±0.10, respectively, There was no significant difference (t= -0.561, P =0.578); 

Trans-PRK and SMILE are safe, effective and stable, and SMILE is slightly better than trans-PRK in terms of predictability.