Visante anterior segment OCT in a patient with gas bubbles in the anterior chamber after femtosecond laser corneal flap formation.

A patient with anterior chamber gas bubbles after LASIK flap formation with femtosecond laser is presented. A 33-year-old male patient had LASIK for myopia with corneal flap formation with IntraLase FS30 femtosecond laser. In the right eye, air bubbles were observed in anterior chamber after successful flap formation. Laser correction was completed successfully, by Wavelight Allegretto Wave Eye-Q excimer laser, without eye-tracker. Visante anterior segment optical coherence tomography imaging displayed that the pocket extended to limbal area, with stromal bed thickness of >600 microm at that area. We propose as possible causes of the air bubbles scattering of femtosecond laser beam producing direct photodissociation of aqueous humor, or direct cavitation effect in aqueous humor due to rapid pressure changes in corneal lamellar interface during the femtosecond laser procedure. Other causes such as migration of intrastromal bubbles through peripheral corneal stroma and trabecular meshwork, or through posterior stroma and endothelium, seem to be unlikely.