Prognostic factors in trabeculectomy with mitomycin C having history of previous glaucoma surgery.

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.