Temporal corneal phacoemulsification combined with superior trabeculectomy: a controlled study

Abstract

Objective: To determine the intraocular pressure (IOP)-lowering effects of combined temporal corneal phacoemulsification and separate incision superior trabeculectomy with those of trabeculectomy alone.

Methods: This is a retrospective case-control study of 40 consecutive patients who underwent combined temporal corneal phacoemulsification and superior trabeculectomy with low-dose 5-fluorouracil (5-FU) (cases), and 40 eyes matched with respect to age, race, preoperative medications, and preoperative IOP that had trabeculectomy alone with low dose 5-FU (controls). Survival analyses for IOP were performed for the cases and controls. We reviewed the charts of 40 consecutive patients who underwent combined temporal corneal phacoemulsification and superior trabeculectomy with low dose 5-FU to determine the effect on IOP, visual acuity, and requirement for glaucoma medications. For controls, we chose 40 eyes matched with respect to age, race, preoperative medications, and preoperative IOP who had trabeculectomy alone with low dose 5-FU. In both groups, trabeculectomy was performed with the same technique, was located superiorly, and employed a limbus-based conjunctival flap. In the combined surgery group, temporal corneal phacoemulsification immediately preceded trabeculectomy and employed a 3.5-mm incision and a one-piece silicone intraocular lens. All patients received 3 or 4 subconjunctival 5-FU injections of 5 mg each over the first 11 postoperative days. Patients were followed up for at least 1 year. Success of trabeculectomy was defined as an IOP less than 22 mmHg and 20% or more reduction from the preoperative level on 2 consecutive follow-up visits, regardless of the use of antiglaucoma medications.

Results: The mean postoperative intraocular pressure was higher in the combined surgery group than in the control group at each follow-up interval (P < 0.05). The mean (+/- SD) IOP reduction was 6.8 (+/- 5.5) mmHg in the combined surgery group, and 10.3 (+/- 7.6) mmHg in the trabeculectomy group at 1 year. The reduction in the number of antiglaucoma medications was 1.6 (+/- 0.9) in the combined surgery group and 2.0 (+/- 1.0) in the control group at 1 year. In the combined surgery group, the mean visual acuity beyond the first postoperative month was significantly better than at baseline (P < 0.001). Kaplan-Meier survival analysis showed that the cumulative success rate at 2 years was 62% in the combined surgery group and 86% in the trabeculectomy group. The time to failure was significantly shorter (P = 0.04) in the combined surgery group.

Conclusions: Combined surgery for cataract and glaucoma is associated with less long-term IOP reduction compared with trabeculectomy alone, despite identical trabeculectomy techniques in both groups. Nevertheless, combined surgery effectively lowers IOP and reduces the long-term requirement for antiglaucoma medications without additional complications. This technique is appropriate in selected patients with coexisting cataract and glaucoma.