Objective: To compare the effectiveness of limbus- and fornix-based conjunctival flaps in patients undergoing trabeculectomy with mitomycin-C augmentation.

Methods: A retrospective review of the records of 71 consecutive eyes of 59 patients who underwent trabeculectomy with mitomycin C. All the patients had at least 6 months of follow-up. The first 35 eyes underwent surgery with a limbal-based flap, whereas all subsequent surgeries were by fornix-based procedures.

Results: No significant difference was detected between the groups with regard to patient demographics, preoperative visual field and intraocular pressure parameters, postoperative intraocular pressures at day 1, months 1, 3, and 6 postoperatively, need for intervention, need for supplementary glaucoma medication, and final visual acuity. There were four cases of overdrainage and hypotony in the limbal-based group, whereas none occurred in the fornix-based group. In all 83% percent of eyes in the limbal-based group achieved intraocular pressures off medication of less than 18 mmHg, whereas 94% of the fornix based group obtained such IOP control. One patient in the limbal-based group developed late postoperative endophthalmitis.

Conclusions: Trabeculectomy with MMC augmentation is a safe and effective procedure for reduction of IOP and visual rehabilitation whether a fornix- or a limbal-based conjunctival flap is utilised. In this series, there was a greater risk of excessive drainage with subsequent hypotonous complications when surgery was undertaken by a limbal-based procedure.