Objective To investigate the clinical efficacy and safety of timolol eye drops in preventing refractive regression in patients with high myopia after small incision lenticule extraction (SMILE).

Methods Sixty-four high myopia patients treated with bilateral SMILE for refractive correction were selected as the observation group, and received routine postoperative medications (antibiotic and glucocorticoid eye drops) combined with timolol eye drops for 3 months. Sixty-four cases were selected as the control group from the same period according to the 1∶1 ratio principle, and only conventional medication was administered after operation. All patients were followed up for 1 year after surgery, and one eye was randomly selected from each patient for the analysis of relevant items. The changes and differences in the uncorrected visual acuity (UCVA), spherical equivalent (SE), corrected intraocular pressure (IOP), mean corneal curvature, and overcorrection diopter were analyzed between two groups at 1 day, 1 week, 1 month, 3 months, 6 months and 1 year after surgery. The differences in the central corneal thickness (CCT), ablation thickness deviation rate, posterior surface height of the corneal apex and incidence of refractive regression between two groups at 1 year after surgery were compared.

Results At 1 day, 1 week, 1 month, 3 months, 6 months and 12 months after surgery, the differences in the UCVA, SE, corrected IOP, mean corneal curvature, and overcorrection diopter between two groups at different time points were statistically significant (P ＜ 0.01). The differences in the UCVA, SE, corrected IOP, mean corneal curvature and overcorrection diopter between two groups were also statistically significant (P ＜ 0.01). Regarding the changing trends, the differences in the UCVA, SE, mean corneal curvature and overcorrection diopter between two groups were statistically significant (P ＜ 0.01), while there was no statistical significance in the corrected IOP (P ＞ 0.05). At 1 year after surgery, there was no statistical significances in the CCT, ablation thickness deviation rate and posterior surface height of the corneal apex between two groups (P ＞ 0.05). The incidence of refractive regression in the observation group was lower than that in control group at 1 year after surgery (P ＜ 0.05). There was no statistical significance in the incidence of adverse reactions between two groups at 3 months after surgery (P ＞ 0.05).

Conclusions Timolol eye drops can effectively reduce the incidence of refractive regression in patients with high myopia after SMILE, and has good clinical application value and safety.