Effect of temporal corneal phacoemulsification on intraocular pressure in eyes with prior trabeculectomy with an antimetabolite.

Abstract

To evaluate the effect of temporal corneal phacoemulsification on intraocular pressure (IOP) in eyes after primary trabeculectomy with intraoperative fluorouracil (5-FU) or mitomycin C (MMC). Retrospective case-control study. Twenty-nine patients who were participants in a prospective randomized double-masked trial comparing the efficacies of intraoperative 5-FU and MMC and who underwent temporal corneal phacoemulsification after the primary trabeculectomy were matched to 29 patients enrolled in the same study who did not undergo cataract surgery. The 2 groups were matched for length of follow-up after the trabeculectomy and the antimetabolite used at the time of trabeculectomy. Comparisons of IOP, visual acuity (VA), and the number of glaucoma medications were made between the 2 groups and within the groups at various follow-up intervals to detect any statistically significant differences. Intraocular pressure before phacoemulsification and at various times postoperatively were compared with IOP in the control group at the matched follow-up times. The mean of all IOP measurements beyond 3 months after phacoemulsification for each subject was significantly higher than the prephacoemulsification IOP (11.8+/-4.2 vs. 8.7+/-4.5 mmHg; P = 0.00003, paired t test). In contrast, the mean IOP remained stable in the control group during the equivalent time period (9.6+/-3.5 vs. 9.1+/-3.1 mmHg; P = 0.42, paired t test). Postphacoemulsification IOP was significantly higher than the corresponding IOP in the time-matched control group (P<0.003, analysis of covariance). Mean VA improved significantly after the phacoemulsification (P = 0.0002) but remained stable in the control group. Temporal corneal phacoemulsification can affect long-term IOP control after trabeculectomy with 5-FU or MMC.