RESUMO
PURPOSE: To determine difference in surgically induced astigmatism (SIA), post-operative intraocular pressure (IOP) and axial length (AL) between single site and twin-site phacotrabeculectomy augmented with Mitomycin C (MMC). DESIGN: Prospective interventional randomised controlled study. METHODS: In a prospective interventional comparative study, eligible patients were scheduled for phacotrabeculectomy. They were randomised to either group A: single site or group B: twin-site phacotrabeculectomy with MMC 0.2 mg/mL. Axial length was measured by using Zeiss IOL master I, pre-operatively and at 1, 3, 6 and 12 months post-operatively. Corneal topography was performed using Bausch and Lomb Orbscan I pre-operatively and at 3, 6 and 12 months post-operatively to analyse surgically induced astigmatism. Vector analysis was used to analyse the surgically induced astigmatism. RESULTS: One hundred and eight eyes of which 55 patients in group A, and 53 patients in group B were enroled for vector analysis. The mean preoperative astigmatic vector power was +0.89 ± 0.4 D and +0.97 ± 0.5 D in group A and B respectively. The mean post-operative astigmatic vector power was +0.78 ± 0.4 D in group A and +0.96 ± 0.5 D in group B at the end of 12 months. Corneal topography showed post-operative superior flattening (51.8% at 3 months and 55.4% at 12 months) in group A (P = 0.072) compared to superior steepening (59.6% at 3 months and 61.5% at 12 months) in group B (P = 0.977). CONCLUSIONS: The two commonly used techniques of combined cataract and glaucoma surgery proved to be efficacious without significant difference in surgical induced astigmatism.
