Long-term outcomes of keratorefractive lenticule extraction for high myopia over -10 diopters

Background To investigate the long-term outcomes of keratorefractive lenticule extraction (KLEx) for correcting super-high myopia. Methods Patients with myopia refractive error of ≤ − 10 diopters (D) with or without astigmatism underwent KLEx were included. The corrected distance visual acuity (CDVA); uncorrected distance visual acuity (UDVA); keratometry; thinnest corneal thickness (TCT); posterior central elevation (PCE); lens density; and axial length were analyzed preoperatively and 1 d and 8 years postoperatively. Results Thirty-two eyes with a mean SE of − 11.13 ± 0.67 D were included. After 8 years, the safety and efficacy indices were 1.02 ± 0.19 and 0.53 ± 0.33, respectively. The CDVA remained unchanged or increased in 29 eyes (91%), but 3 eyes (9%) lost one or two lines. Nineteen eyes (59%) were corrected within ± 1.0 D of the target, and 18 eyes (56%) had a LogMAR value of ≥ 0.3 for UDVA. Mean regression over 8 years was − 1.17 ± 1.22 D. TCT and keratometry values increased significantly from 1 d to 8 years (P < 0.05). PCE remained stable during the follow-up period; however, axial length significantly increased 8 years after KLEx compared to baseline values (P < 0.05). Conclusions KLEx could be an alternative for patients with super-high myopia with or without astigmatism under strict preoperative assessment and appropriate surgical design. Patients should be informed of increased refractive regression risk over time.