Effect of cataract surgery on intraocular pressure in eyes with previous trabeculectomy

Purpose: To determine the course of the intraocular pressure in eyes in which cataract surgery was performed after trabeculectomy. Methods: This was a retrospective study of consecutive patients who were scheduled for routine cataract surgery. The patients had previously undergone glaucoma filtering surgery. Pre- and postoperative data were evaluated. Both the status of glaucoma and the increase in visual acuity were monitored. Results: Patients operated on over a six-year period were enrolled. The mean interval between glaucoma surgery and cataract surgery was 58.1 months. The mean duration of follow-up after cataract surgery was 31.4 months, with a minimum of 12 months. The mean central visual acuity increased by 4 lines. Before cataract surgery, 53% of the eyes had complete success (group 1), while 28% had qualified success (group 2) and the remaining 19% were failures (group 3). From group 1, 61% remained a complete success until the last visit. No eye of group I developed a failure. In group 2, 23% were a complete success at the final follow-up, while 4% failed. In group 3, only 35% were failures while the remaining 65% were a complete or qualified success. Conclusions: Eyes with a well-controlled intraocular pressure following trabeculectomy seem to have a favorable prognosis after subsequent cataract surgery. Eyes with qualified success or failure before cataract surgery have a slight chance of improvement in intraocular pressure control. Cataract surgery had no markedly negative effect on the intraocular pressure overall. Performing trabeculectomy and cataract surgery at different times may still be a feasible option as opposed to combined procedures.