Purpose: To evaluate the prognostic factors for surgical outcomes of subsequent trabeculectomy with mitomycin C (MMC) after prior incisional glaucoma surgery.
Methods: We reviewed medical records of a total cohort of 781 trabeculectomies with MMC, and selected 125 patients (125 eyes). The primary endpoints included persistent intraocular pressure (IOP) of ≥21 or <5 mmHg, the need for additional glaucoma surgery and deterioration of visual acuity to no light perception. Univariate and Multivariate analyses were performed by using the Cox proportional hazards model.
Results: The mean follow-up period was 26.8 months. The probabilities of success at 1, 2, and 3 years were 80.6, 72.2, and 70.6 %, respectively. Multivariate analysis showed that a shorter time interval between prior glaucoma surgery and subsequent trabeculectomy [relative risk (RR), 0.8867/year; P = 0.0090] and the number of prior trabeculectomies (RR, 2.2645; P = 0.0029) were significant prognostic factors for subsequent failure of trabeculectomy with MMC.
Conclusion: A short time period between prior glaucoma surgery and subsequent trabeculectomy and the number of prior trabeculectomies are associated with surgical failure of subsequent trabeculectomy with MMC.