A Prospective Randomised Trial of Trabeculectomy Using Mitomycin C Vs an Ologen Implant in Open Angle Glaucoma

Purpose: The aim of this study is to assess the efficacy and complications of trabeculectomy with a biodegradable implant (ologen implant) vs trabeculectomy using mitomycin C (MMC) in patients with medically uncontrolled open-angle glaucoma in a prospective randomised clinical trial.

Methods: In the MMC group (10 patients), trabeculectomy was performed according to standard protocols. In the ologen group (10 patients) after standard trabeculectomy the implant was positioned on top of the scleral flap and no MMC was applied. Follow-up was continued for 12 months after surgery and included testing of intraocular pressure (IOP), visual acuity, visual field, ultrasound biomicroscopy, and filtering bleb score.

Results: The mean preoperative IOP was 24.8+/-8.9 mm Hg for all patients enrolled. At 1 year after surgery, the mean IOP was 15.6+/-2.4mm Hg in the ologen group (P<0.01, 43% reduction) and 11.5+/-4.1 mm Hg in the MMC group (P<0.01, 50% reduction). No anti-glaucomatous medication was necessary in the MMC group in the first year of follow-up, whereas five patients in the ologen group required topical treatment. The absolute success rate was 100% in the MMC group and 50% in the ologen group (P=0.01). After 1 year, filtering blebs developed significantly more avascular areas in the MMC group (score=1.4) than in the ologen group (score=2.8; P<0.01).

Conclusion: The complete success rate using trabeculectomy with the ologen implant is lower than that achieved by trabeculectomy with MMC. However, the bleb morphology caused more problems in the MMC group (avascularity score).