Long-term Outcomes and Prognostic Factors for Trabeculectomy with Mitomycin C in Eyes with Uveitic Glaucoma: a Retrospective Cohort Study

Purpose: To elucidate the long-term outcomes and prognostic factors for trabeculectomy with mitomycin C (MMC) in eyes with uveitic glaucoma (UG).

Methods: A retrospective, consecutive, comparative cohort study was conducted with 204 patients who underwent trabeculectomy with MMC between 1999 and 2008 at 2 Japanese clinical centers. The study group included 101 eyes with UG and 103 eyes with primary open-angle glaucoma (POAG). Surgical failure was defined as intraocular pressure levels of ≥21 mm Hg or an additional glaucoma surgery. Kaplan-Meier survival curves for surgical failure were compared between UG and POAG eyes, and prognostic factors for surgical failure of trabeculectomy in UG eyes were analyzed by the Cox proportional hazards model. Secondary outcome measures included comparisons of the frequency of additional cataract surgery and other surgical complications after trabeculectomy between UG and POAG eyes.

Results: The mean follow-up periods (±SD) were 34.7±37.9 and 37.7±34.7 months (median, 24.0 and 27.4 mo) for UG and POAG, respectively. The subtypes of uveitis were granulomatous uveitis (n=20) including sarcoidosis (n=12), Vogt-Koyanagi-Harada disease (n=5) and varicella zoster virus uveitis (n=3), Behçet disease (n=10), Posner-Schlossman syndrome (n=5), and other types of UG (n=12). Fifty-four eyes were diagnosed with idiopathic UG. The 3-year probabilities of success after trabeculectomy were 71.3% and 89.7% for UG and POAG, respectively (P=0.0171). A multivariable model showed that UG eyes with previous cataract surgery [relative risk (RR)=2.957, P=0.0344)] and granulomatous uveitis (RR=3.805, P=0.0106) were associated with surgical failure. UG eyes experienced more frequent cataract surgeries after trabeculectomy than POAG eyes: the 3-year probabilities of additional cataract surgery of 62.6% and 10.7% for UG and POAG, respectively (P<0.0001). There was no significant difference in the frequency of surgical complications such as bleb leakage, hypotensive maculopathy, severe anterior-chamber hemorrhage, and infectious endophthalmitis.

Conclusions: Trabeculectomy with MMC was less effective in maintaining intraocular pressure reduction in UG eyes than in POAG eyes. The prognostic factors for surgical failure of trabeculectomy in UG eyes were previous cataract surgery and granulomatous uveitis. In addition, UG eyes after trabeculectomy more frequently required additional cataract surgery.