Outcomes of trabeculectomy after descemet stripping automated endothelial keratoplasty: a comparison with penetrating keratoplasty

Abstract

Purpose: To compare the outcomes of trabeculectomy surgery after Descemet stripping automated endothelial keratoplasty (DSAEK) to penetrating keratoplasty (PK).

Design: Retrospective case-control study.

Methods: Patients within an institutional setting who underwent trabeculectomy with mitomycin C (MMC) for uncontrolled elevated intraocular pressure (IOP) after corneal graft surgery were included. Patients with pre-existing glaucoma were excluded. Twenty patients with trabeculectomy after DSAEK and 41 patients with trabeculectomy after PK were analyzed. The main outcome measure was IOP control at 12 months. Secondary outcome measures were postoperative interventions including reinstatement of IOP-lowering medications, bleb needling with 5-fluorouracil (5FU) or further glaucoma surgery, and the incidence of complications related to trabeculectomy and/or corneal graft surgery.

Results: There was no difference in pre-trabeculectomy IOP between DSAEK vs PK group (35.5 ± 10.1 vs 32.9 ± 8.9, P = .31). At 12 months after trabeculectomy, mean IOP in the DSAEK group was lower compared to the PK controls (10.6 ± 3.2 vs 14.6 ± 8.5, P = .04). The proportion of patients who achieved an IOP less than 12 mm Hg was significantly higher in the DSAEK group (80.0% vs 48.6%, P = .03). The proportions of eyes that required intervention after trabeculectomy were comparable between the 2 groups (DSAEK vs PK, all interventions: 20.0% vs 39.5%, P = .15; IOP-lowering medications required: 15.0% vs 39.5%, P = .08; needling with 5FU: 20.0% vs 23.7%, P > .99; further glaucoma surgery: 0% vs 13.2%, P = .15). Corneal graft failure arising after trabeculectomy was seen in 10.0% of DSAEK cases and in 10.5% of PK controls (P = 1.0).

Conclusion: Compared to trabeculectomy after PK, trabeculectomy after DSAEK achieved lower mean IOP at 12 months, and a larger proportion of DSAEK patients achieved an IOP of less than 12 mm Hg. There was no difference in the need for intervention after trabeculectomy, or incidence of other complications. Trabeculectomy is an effective surgical procedure for the management of postgraft ocular hypertension in DSAEK patients, and DSAEK may have an advantage in terms of success of trabeculectomy surgery over PK.