Purpose: To compare changes in intraocular pressure (lOP) during femtosecond laser pretreatment of cataract between glaucomatous eyes and nonglaucomatous eyes.

Setting: Launceston Eye Institute and Launceston Eye Hospital, Launceston, Australia.

Design: Nonrandomized interventional prospective case series.

Methods: Patients with clinically stable primary open-angle glaucoma (POAG) having femtosecond laser pretreatment were compared with a concurrent cohort of patients with healthy eyes having the same procedure. Pretreatment was performed using a fluid-filled optical docking system (Liquid Optics Interface). With the patient supine, the lOP was measured at 4 time points using a rebound tonometer (lcare Pro).

Results: The study comprised 143 eyes of 97 patients. Forty-three eyes (30.1%) had documented glaucoma. The mean baseline lOP was 20.2 mm Hg ± 4.2 (SO) in glaucomatous eyes and 18.9 ± 4.0 mm Hg in nonglaucomatous eyes (P = .06). The mean change in lOP values between each time frame and baseline was as follows: vacuum-on, 13.8 ± 9.9 mm Hg and 11.1 ± 6.9 mm Hg, respectively (P = .06); after treatment, 17.4 ± 7.4 mm Hg and 14.1 ± 7.2 mm Hg, respectively (P = .014); after undocking of vacuum, 9.9 ± 5.4 mm Hg and 8.7 ± 5.7 mm Hg, respectively (P = .24).

Conclusions: Femtosecond pretreatment caused a greater transient rise in lOP after treatment and a higher residual lOP after vacuum undocking in glaucomatous eyes than in nonglaucomatous eyes. This is well tolerated short term; however, long-term implications for eyes with glaucoma are unknown at present.