Vertical Gas Breakthrough Complicating Femtosecond LASIK: Incidence, Management, and Visual Outcomes in a Retrospective Case Series.

PURPOSE: To characterize vertical gas breakthrough (VGB) during femtosecond LASIK (FS-LASIK) by frequency, location, management, and early visual outcomes.

SETTING

Care-Vision Laser Center, Tel Aviv, Israel.

DESIGN

Retrospective consecutive case series.

METHODS

All FS-LASIK procedures (June 2020-January 2023) were reviewed. Cases with an uncut area during flap creation were identified; VGB was confirmed on intraoperative video as gas breaching the lamellar plane with subepithelial accumulation. Management was classified as proceed, manual completion (crescent/keratome), conversion to PRK, or procedure abortion. Primary outcomes were UDVA and CDVA at the last postoperative refraction visit; postoperative day (POD) was summarized, and complications recorded.

RESULTS

Among 7,746 eyes, uncut areas occurred in 79 (1.0%) and VGB in 23 (0.3%). Mean age was 36±12 years; 14/23 (60.9%) were female. VGB was located near the hinge in all eyes, with central extension in 3/23 eyes (13.0%). Management included proceeding as planned in 10/23 (43.5%), manual completion in 4/23 (17.4%), same-day conversion to PRK in 7/23 (30.4%; three were primary, four after attempted flap elevation), and procedure abortion in 2/23 (8.7%). Endpoint timing was POD 70±44 (median 62 [58-78]; range 7-184). Postoperative acuity was available in 21/21 eyes for both UDVA and CDVA; mean decimal UDVA was 0.96±0.21 and CDVA 1.03±0.09. Accuracy was high: 81.0% and 90.5% were within ±0.50 D and ±1.00 D of target. Complications were infrequent: buttonholes occurred in 2/21 treated eyes (9.5%) and grade 1 haze after PRK occurred in 2/21 treated eyes (9.5%).

CONCLUSIONS

VGB was uncommon, usually peripheral, and manageable with surgeon-directed adjustments. Early postoperative visual outcomes at the last refraction visit were favorable and similar across management strategies.