Intraocular pressure rises during laser L in situ keratomileusis: Comparison of 3 femtosecond laser platforms

Abstract

Purpose: To measure intraocular pressure (IOP) elevations in porcine eyes during laser in situ keratomileusis (LASIK) performed using 3 femtosecond laser platforms.

Setting: Clinica Novovision, Madrid, Spain.

Design: Experimental study. Methods: Three femtosecond devices, the iFS 150 kHz, which is the newest-generation IntraLase with a flat interface, and the Victus and LenSx, which are both dual femtosecond lasers with curved interfaces, were used to create lamellar corneal flaps in freshly enucleated porcine eyes. The IOP was recorded during placement of the suction ring on the eye (suctioning phase) and during the intrastromal laser application for flap creation (cutting phase) using a manometric technique with direct cannulation to the anterior chamber.

Results: Twenty-one eyes were analyzed (7 per group). The mean IOP increase during suctioning was significantly higher with the iFS system (78.14 mm Hg +/- 23.6 [SD]) than with the Victus system (20.28 +/- 6.7 mm Hg) (P = .0001). The LenSx system performed the suctioning and applanation phases simultaneously, making it impossible to obtain the results of the suctioning phase alone. The mean IOP elevation during the cutting phase was significantly lower with the LenSx system (20 +/- 5.3 mm Hg) than with the iFS (108.1 +/- 17.0 mm Hg) and Victus (96.4 +/- 16.8 mm Hg) systems (P = .0001). The total surgical time was significantly lower with the LenSx system (17.21 +/- 0.7 seconds) than with the iFS (25.10 +/- 4.3 seconds) and Mctus (33.40 +/- 0.7 seconds) systems (P = .0001).

Conclusion: The preliminary results suggest that the iFS and Mctus systems induced higher IOP increases and required longer surgical times to cut a LASIK flap than the LenSx system.