Comparison of long term intraocular pressure control following small flap vs conventional trabeculectomy

Abstract

Background: Trabeculectomy using a small scleral flap appears to provide medium to long-term IOP control comparable to large flap techniques and may offer potential advantages: reduced surgical tissue trauma, a larger area of undisturbed sclera and conjunctiva should repeat surgery be required, and reduced astigmatism induction. Aims & Objective: To evaluate the long term intraocular pressure (IOP) control of small flap trabeculectomy (microtrabeculectomy) vs conventional trabeculectomy. Materials and Methods: A prospective case control study of small flap trabeculectomy (group I) as against conventional trabeculectomy (group II) was performed on 50 eyes from 50 patients in each group with a minimum follow up of 2 years. Results: All patients had a minimum follow up of 2 years, The mean (SD) intraocular pressures at presentation and preoperatively were 34.3 (5.6) and 23.7 (3.7) mm Hg in group I and 35.2(4.5) and 24.2(2.9) mm Hg in group II. The mean (SD) IOP at 6 months, 1 & 2 years was 12.5 (4.0), 12.9 (4.1), 13.5 (4.5) respectively in group I and 12.0 (4.4), 12.7 mmHg (3.6), 13.0 (3.9) respectively in group II. There was no significant difference in IOP levels at any of the analysis points by one way ANOVA. Conclusion: Small flap trabeculectomy (microtrabeculectomy) is effective at reducing IOP in uncomplicated glaucoma patients with IOP control similar to filtering surgery utilising larger scleral flaps. Well-constructed scleral flaps of both sizes were able to achieve and maintain IOP levels well within the desired range and the small flaps had advantages of avoiding complications associated with larger flaps.