Incidence and outcome of suction loss during corneal lenticule extraction with the femtosecond laser application CLEAR

Abstract

A femtosecond laser creates an intrastromal lenticule while the eye is immobilized by vacuum in refractive corneal lenticule extraction to correct myopia. Suction loss has a 0.72% overall incidence and may result in an incomplete cut; the procedure can then be completed using the same or different techniques. While previous laser platforms used corneal suction, the recent lenticule extraction (CLEAR) application for the Ziemer Z8 femtosecond laser (Ziemer Group, Port) uses scleral suction; studies on suction loss with this vacuum system are lacking. A total of 652 eyes from 357 CLEAR patients were thus included in a consecutive, single-institution, retrospective study. Suction loss occurred in three patients’ left eyes (0.46%) due to a strong involuntary eyelid contraction. After an early suction loss in patient #1, the procedure was successfully repeated with the same parameters. Suction loss occurred after the completion of the posterior cut and at 44% of the anterior cut in patient #2. The laser procedure appeared to have been completed in patient #3, but the lenticule had not been delineated temporally due to false suction on the conjunctiva. Thin flap femtosecond laser in situ keratomileusis (LASIK) was used to complete the refractive procedure in patients #2 and #3. Uncorrected distance visual acuity was 20/20 or better in all three eyes at 6 months. Finally, suction loss during CLEAR was uncommon and had a favorable prognosis. Repeat lenticule extraction or femtosecond LASIK can be performed on the same day to complete the treatment.