Abstract: Objective To evaluate the efficacy of transepithelial photorefractive keratectomy (TransPRK) in the treatment of refractive regression after femtosecond laser small incision lenticule extraction (SMILE). Design Retrospective case series. Participants A total of 20 patients (22 eyes) with refractive regression after SMILE who were treated at Ganzhou Aier Eye Hospital from January 2018 to January 2023. Methods All patients underwent TransPRK surgery using the AMARIS 500E excimer laser system, with the corneal visual center as the ablation center. After ablation, the cornea was rinsed with balanced saline solution at 0~4°C. Patients were followed up for 1 year postoperatively. Changes in uncorrected visual acuity (UCVA), refractive error, modulation transfer function cutoff frequency (MTF cut-off), Strehl ratio (SR), objective scatter index (OSI), intraocular pressure (IOP), and central corneal epithelial thickness were observed before surgery and at 1 day, 3 days, 1 week, 1 month, 3 months, 6 months, and 12 months postoperatively. Main Outcome Measures UCVA, refractive error, MTF cut-off frequency, SR, OSI, IOP, and central corneal epithelial thickness. Results Compared with preoperative values (UCVA: 0.33±0.10), UCVA was significantly improved at all postoperative follow-up time points (F=56.654, P<0.001), and refractive error was significantly reduced (F=68.112, P<0.001). At 12 months postoperatively, UCVA improved to 1.03±0.11 (t=20.05, P<0.001); refractive error improved from (-2.03±0.34) D to (+0.74±0.17) D (t=17.58, P<0.001); central corneal epithelial thickness increased from (52.80±1.54) μm to (60.83±2.11) μm (t=14.42, P<0.001); mean corneal curvature decreased from (44.42±1.43) D to (36.44±1.62) D (t=17.33, P<0.001). In terms of visual quality, at 12 months postoperatively, MTF cut-off frequency was (41.03±1.70) c/deg (t=18.06, P<0.001), SR was 0.33±0.08 (t=6.82, P<0.001), both significantly improved compared with preoperative values (32.20±1.54 c/deg and 0.20±0.04, respectively); OSI was 0.59±0.11, significantly decreased compared with the preoperative value of 1.27±0.11 (t=20.50, P<0.001). IOP was significantly decreased at all postoperative time points compared with preoperative values (F=20.102, P<0.001), but there were no significant differences among postoperative time points (all P>0.05). No severe complications such as corneal haze occurred in any patient postoperatively. Conclusion Transepithelial photorefractive keratectomy is safe and effective for treating refractive regression after SMILE surgery.

Key words:  Transepithelial photorefractive keratectomy (TransPRK), Small incision lenticule extraction (SMILE), Refractive regression