Intraocular pressure measurements during flap preparation using 2 femtosecond lasers and 1 microkeratome in human donor eyes

Abstract

Purpose: To evaluate and compare intraocular pressures (IOPs) during flap preparations performed using 2 femtosecond lasers and a mechanical microkeratome in human donor globes.

Setting: University Medical Center Mainz, Mainz, and Euroeyes Clinic Stuttgart, Stuttgart, Germany.

Design: Experimental study.

Methods: A cannula was inserted through the optic nerve in human globes. The IOP was obtained continuously during flap preparation using the 60 kHz Intralase femtosecond laser, the 200 kHz Visumax femtosecond laser, or the Amadeus II microkeratome. For each experiment, a normal lamellar flap preparation (regular procedure) and a worst-case procedure (femtosecond laser interface was pressed against globe until docking maneuver was aborted) were performed.

Results: During the regular procedure, the mean maximum IOP measured was 181.3 mm Hg (range 159.1 to 194.8 mm Hg) with the 60 kHz femtosecond laser, 77.6 mm Hg (range 58.1 to 100.3 mm Hg) with the 200 kHz femtosecond laser, and 198.1 mm Hg (range 162.8 to 299.6 mm Hg) with the microkeratome. During the worst-case procedure, the maximum measured IOP was 319.7 mm Hg (range 299.1 to 341.2 mm Hg) with the 60 kHz laser and 120.4 mm Hg (range 118.1 to 134.7 mm Hg) with the 200 kHz laser.

Conclusion: Maximum IOPs during corneal flap preparations in human enucleated eyes were lower during performance of a regular procedure and a worst-case procedure with the 200 kHz femtosecond laser than with the 60 kHz femtosecond laser and the mechanical microkeratome.

Financial disclosure: Dr. Sekundo is a member of the Scientific Advisory Board of Carl Zeiss Meditec AG, Jena, Germany. No author has a financial or proprietary interest in any material or method mentioned.