Surgical Outcomes of Trabeculectomy Alone versus Trabeculectomy with Manual Small Incision Cataract Surgery Following Acute Angle Closure Glaucoma: A Comparative Study

Abstract

Introduction: Acute Angle Closure Glaucoma (AACG) is an ophthalmic emergency and is managed medically. Therapeutic options for the management of the post congestive phase are varied and no procedure has a documented therapeutic superiority over the other. Two established procedures were therefore chosen and compared to determine their therapeutic efficacy. Aim: To compare the surgical results of combined manual Small Incision Cataract Surgery (SICS) and trabeculectomy with standalone trabeculectomy in patients following an attack of AACG, with a final aim to decide which would be the better therapeutic approach in such a situation. Materials and Methods: This was a prospective observational study done in Bankura Sammilani Medical College located in West Bengal, India. Sixteen patients presenting with AACG in a 19 months study period from October 2019-April 2021 and having 50% or more synechial angle closure on indentation gonioscopy were selected for this study after obtaining necessary ethical clearance. Eight of them underwent trabeculectomy alone (Group A) and the rest underwent a combined procedure of trabeculectomy and SICS (Group B). They were followed-up for a six-months period and compared on the basis of Intraocular Pressure (IOP) control, Anterior Chamber (AC) depth and the requirement for further surgery. Results: Mean IOP following surgery at the end of six weeks in Group A was 15.98±1.56 mmHg whereas in Group B it was 12.01±1.18 mmHg. Results were compared by unpaired t-test, and the difference was statistically significant (p<0.001). Three out of eight patients (37%) in Group A developed cataract which caused a reduction in visual acuity and needed cataract surgery within the six months follow-up period but none of the patients in Group B needed any additional surgery. One patient in Group A needed additional medications due to uncontrolled IOP after surgery but no such event was noted in Group B. Seventy five percent patients in Group A had Grade 2 angles whereas 87% patients in Group B had Grade 4 angles as estimated by Van Herrick’s method. Conclusion: Combined trabeculectomy and SICS offers a better level of postoperative IOP control than trabeculectomy alone, and perhaps offers a better therapeutic option following AACG. Also, the chances of postoperative cataract formation and associated visual debility are eliminated.