Results of phacoemulsification in eyes with preexisting glaucoma filters

PURPOSE: To evaluate the intraocular pressure (IOP), best corrected visual acuity (BCVA), and glaucoma medication requirements in patients having phacoemulsification after preexisting glaucoma filters. SETTING: Ophthalmic Consultants of Boston, Boston, Massachusetts, USA. METHODS: A retrospective analysis of 58 eyes that had temporal phacoemulsification via a clear corneal (32 eyes) or a scleral tunnel (26 eyes) approach after filtration surgery was performed with a minimum follow-up of 12 months. Two-tailed homoscedastic t tests were used for statistical analysis. RESULTS: The mean preoperative IOP in all eyes was 11.8 mm Hg +/- 4.2 (SD), and the mean final postoperative IOP was 13.7 +/- 4.6 mm Hg (P<.022). The mean preoperative logMAR equivalent BCVA was 0.8 +/- 0.4, which improved to a mean of 0.4 +/- 0.4 postoperatively (P<.0000002). There was no statistically significant change in glaucoma medication requirements postoperatively. The differences in IOP, BCVA, and postoperative glaucoma medication requirements were not statistically significant between the clear corneal group and the scleral tunnel group or between patients who received mitomycin at the time of filtration surgery and those who did not. There were no intraoperative complications; 1 patient required additional glaucoma surgery. CONCLUSION: Clear corneal or scleral tunnel phacoemulsification in the setting of a preexisting glaucoma filter was associated with improved BCVA, a small but statistically significant increase in IOP, and stability in the number of glaucoma medicines required for IOP control over a minimum follow-up of 1 year.