Long-term results of trabeculectomy with mitomycin C applied under the scleral flap

Abstract

The objective of this study was to look at the long-term safety, and the effectiveness on intraocular pressure, of trabeculectomy and mitomycin C (MMC) applied under the scleral flap. All patients undergoing trabeculectomy and MMC application during the period June 1992-August 1995 were included. Data on 30 eyes of 25 patients were reviewed. We looked at sociodemographic variables, intraocular pressure (IOP) control, visual acuities and bleb morphology. Bleb-related and other complications were also noted. Statistical analysis was performed with Student's paired t-test, and Kaplan-Meier life table analysis was utilised for IOP control. The mean age of patients (12 male and 13 female) was 56 years (range 7-79 years), with a mean follow-up period of 8.7 years (range 5-11 years). There was one eye with blebitis/endophthalmitis at 4 years, and one eye developed hypotonous maculopathy. Ten eyes were noted to have poor bleb morphology due to long-standing fibrosis, and the majority of these underwent further surgical intervention with 5-fluorouracil (5FU) needling. The IOP control showed good results, with mean IOP falling from a preoperative level of 24.8-15.2 mmHg at the last visit, with good probability of maintenance in the longer term. The main reason for reduced vision was pre-existing co-morbidity and development of lenticular opacities. In the series with the longest follow-up period our study showed that trabeculectomy augmented with MMC under the scleral flap in these difficult cases can achieve good long-term IOP control and is associated with minimal long-term complications.