Intraocular pressure variation during femtosecond laser–assisted cataract surgery using a fluid-filled interface

PURPOSE: To evaluate intraocular pressure (IOP) during femtosecond laser-assisted cataract surgery using a fluid-filled interface. SETTING: Ruhr University Eye Clinic, Bochum, Germany. DESIGN: Prospective clinical trial. METHODS: The absolute IOP was measured with a modified Schiotz tonometer before and after laser-assisted cataract surgery with and without a fluid-filled interface (Liquid Optics interface, Catalys Precision Laser System). RESULTS: The study evaluated 100 eyes. Tonometry and laser cataract surgery were completed successfully in all eyes. The mean preoperative IOP was 15.6 mm Hg ± 2.5 (SD). Upon application of the suction ring and vacuum, the mean IOP rose to 25.9 ± 5.0 mm Hg and remained nearly constant after the laser procedure (27.6 ± 5.5 mm Hg). After removal of the suction ring, the mean IOP was 19.1 ± 4.4 mm Hg. The IOP 1 hour after surgery was not significantly higher than the preoperative values. CONCLUSIONS: The results indicate a minor increase in IOP using the fluid-filled interface. This is in strong contrast to substantially higher values reported in the literature with flat and curved applanating contact interfaces.