Using the Early Postoperative Intraocular Pressure to Predict Pressure Control After a Trabeculectomy

PURPOSE:The goal of this study was to identify the early postoperative intraocular pressure (IOP) that predicts low pressure control after a trabeculectomy with mitomycin C. MATERIALS AND METHODS:This study retrospectively analyzed the medical records of the initial trabeculectomy with mitomycin C in patients with primary open-angle glaucoma. We established 2 target postoperative IOPs, ≤11 and ≤15 mm Hg. The preoperative and early postoperative factors contributing to the success and failure of postoperative IOP control were studied by multiple regression analyses. These factors included the sex and age of patients, record of cataract surgery, number of preoperative medications, preoperative IOP, IOP recorded 2 weeks after surgery, laser suture lysis after surgery, and the presence of a shallow anterior chamber and choroidal detachment during the first month after surgery. The optimal IOP levels 2 weeks after surgery for long-term IOP control were examined using the Kaplan-Meier survival analyses. RESULTS:Sixty-six patients (66 eyes) with open-angle glaucoma participated in the study. The age and IOP 2 weeks after surgery were selected as the confounding factors affecting the probability of successfully satisfying both target IOPs;≤11 and≤15 mmHg postoperatively. An IOP under 8 mm Hg at 2 weeks after surgery was found to be associated with maintaining the postoperative IOP at either ≤11 and ≤15 mm Hg for an extended period. CONCLUSIONS:An IOP of 8 mm Hg was associated with successful outcomes in patients undergoing trabeculectomy. Also, younger age was found to be a risk factor for surgical failure.