Efficacy of amniotic membrane-assisted bleb revision for elevated intraocular pressure after filtering surgery

PURPOSE To compare the effectiveness of standard revision surgery using mitomycin C (MMC) with revision using amniotic membrane transplantation and MMC for elevated intraocular pressure (IOP) after trabeculectomy. PATIENTS AND METHODS A retrospective, nonrandomized comparative study of 36 eyes of 36 patients with a failed trabeculectomy. Patients were divided into two groups, ie, a nonamnion-transplanted group and an amnion-transplanted group. The amniotic membrane was placed on the scleral flap under the conjunctiva in the amnion-transplanted group. Both groups recovered filtration of aqueous humor from the surgical site with the adjunctive use of MMC. The changes in IOP and cumulative survival rate were compared for the two groups. Success was defined as a 30% reduction in IOP from the preoperative IOP and maintenance below 21 mmHg with or without the use of antiglaucomatous agents. RESULTS The mean preoperative IOP was not significantly different in the two groups. The mean postoperative IOP in the nonamnion group, 12.1 +/- 5.5 mmHg, was significantly lower than the IOP in the amnion group, 16.0 +/- 3.7 mmHg. Survival curves in the two groups did not reach significantly different levels. CONCLUSIONS Conventional surgical bleb revision with MMC can significantly reduce the elevated IOP associated with a failed filtration bleb. The use of an amniotic membrane transplant did not improve the surgical outcome in our cases.