OCT Study of the Femtosecond Laser Opaque Bubble Layer

Abstract

To characterize the location and regularity of the opaque bubble layer (OBL) in the corneal stroma after femtosecond laser-assisted LASIK (FS-LASIK) flap generation. In this prospective study, 30 eyes of 15 patients who had FS-LASIK surgery for myopia, astigmatism, and/or hyperopia were included. Screen captures were obtained at the end of the flap creation and the eyes with hard type OBL were immediately imaged with anterior segment optical coherence tomography. The mean age of the 9 men and 6 women was 40 ± 11.3 years (range: 22 to 60 years). Seven eyes (23.3%) developed hard type OBL that was typically localized in the central cornea beneath the LASIK flap and, in the majority of cases, located close to the hinge of the flap. Three of the seven eyes had OBL only within the laser cut, whereas the four other eyes had OBL in a spotty distribution within the stromal bed beneath the flap. None of the eyes had an accumulation of OBL within the flap itself. The excimer laser ablation of a stroma with OBL may be different from that of a stroma without OBL. Management of OBL when it occurs due to flap production, including allowing the bubble to dissipate when they overlie the pupil, is important to obtain the best outcomes with femtosecond laser-assisted LASIK. [J Refract Surg. 2017;33(1):18-22.].