Flap Loss in More Than 1 Million LASIK Procedures: Incidence, Management, and Visual Outcomes

Purpose To analyze the incidence of flap loss in laser in situ keratomileusis (LASIK), management of this complication, and visual outcomes. Methods This multicenter, multisurgeon, single-protocol, retrospective case series study enrolled patients who had undergone LASIK and experienced flap loss. Patients were operated on using a Moria LSKONE or a Moria One-Use-Plus-SBK microkeratome (Microtech Inc, Moria Ophthalmic Instruments). The study assessed uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), predictability (accuracy to the intended target), safety (change in Snellen lines of CDVA), and efficacy (difference between UDVA and CDVA). A control group was created to compare refractive outcomes, predictability, safety, and efficacy for eyes with flap loss and patients whose LASIK procedure was free of complications. Results The analysis included 1,008,849 eyes. Flap loss occurred in 16 eyes from 16 patients. Patients received topical mitomycin C (MMC) after flap loss in 9 cases (7 did not receive MMC). A bandage contact lens was applied in all 9 cases. Mean UDVA was significantly worse in the group of patients with a flap loss ( P = .013), although the difference in CDVA was not ( P = .077). Both the mean efficacy index and the mean safety index were significantly worse in patients with flap loss ( P = .004 and .02, respectively). Conclusions Flap loss is an extremely rare complication after LASIK. It can be managed with MMC and a bandage contact lens, with a reasonable safety index and visual outcomes. [ J Refract Surg . 2025;41(4):e318–e324.]