The picosecond laser for nonmechanical laser in situ keratomileusis

Abstract

Purpose: To introduce the clinical use of the Nd:YLF picosecond laser as a nonmechanical microkeratome.

Methods: A commercially available Nd:YLF picosecond laser (25 microJ/pulse, 30 psec, 1053 nm) was used to deliver intrastromal pulses of focused high power laser light to generate a flap for laser in situ keratomileusis (LASIK) and perform picosecond laser keratomileusis (PLK) in two partially sighted patients with high myopia.

Results: Case #1: A 6 mm, 150 microns flap for LASIK was successfully created and the underlying stroma treated with an excimer laser for a target correction of -15.00 D of myopia. Good corneal clarity and a refractive change of -14.00 D was recorded 2 months postoperatively. Case #2: Both eyes of a high myope (-22.00 D right eye, -21.50 D left eye) underwent picosecond laser keratomileusis, removing a 3.2 mm diameter lenticule of 120 microns thickness under a 200 microns flap. Postoperative refraction was -2.00 D at 7 months in the right eye and -0.75 D at 2 months in the left eye with improvement of spectacle-corrected visual acuity from 20/200 to 20/70 in each eye.

Conclusion: The Nd:YLF picosecond laser can be safely used in creating a corneal flap for LASIK and in performing picosecond laser keratomileusis for high myopia. Future refinements in the laser will include a larger flap diameter and femtosecond pulsing capability.