Success and Failure Factors for Trabeculectomy in Glaucomatous Patients in Southwest China: A 325 Eyes Analysis

Abstract

Purpose To evaluate the outcomes and elucidate the success and failure factors for trabeculectomy with mitomycin C (MMC) in Southwest Chinese patients. Methods A retrospective correlational study was conducted on the glaucomatous patients who underwent initial trabeculectomy with MMC in Southwest Hospital and had been followed up for 1-3 years. A complete success for surgery is defined as a postoperative intraocular pressure (IOP) > 5 and ≤ 21 mmHg and 20% reduction of IOP compared to preoperative, without IOP-lowering medications. A qualified success for surgery is defined as the abovementioned postoperative IOP with or without IOP-lowering medications. The primary outcomes were IOP, the number of IOP-lowering medications, and cumulative success rate. The secondary outcomes included best corrected visual acuity (BCVA), mean deviation (MD) of visual field, major complications, and risk factors for surgical failure. Results A total of 325 eyes of 261 glaucomatous patients had been included in our study. Both the mean IOP and the number of IOP-lowering medications were significantly decreased from 32.9 ± 12.0 mmHg to 16.4 ± 5.7 mmHg (P<0.0001) and 3.0 ± 0.9 to 0.9 ± 1.0 (P<0.0001), respectively, at the last visit. The cumulative complete success rate and qualified success rate were 77.8% and 92.0% at 1-year follow-up, and 47.2% and 77.7% at 3-year follow up. There were no significant differences in surgical outcomes between primary angle-closure glaucoma (PACG) and primary open angle glaucoma (POAG). In PACG patients, the success rates of trabeculectomy were comparable with those of phacotrabeculectomy. Hypertension (HR=1.904, P=0.011), encapsulated bleb (HR=2.756, P<0.001), and more preoperative topical medications (HR=2.475, P=0.008) were risk factors for surgical failure. Conclusions The qualified success rate of trabeculectomy with MMC in glaucomatous patients in Southwest China is 92.0% at 1-year follow-up, and 77.7% at 3-year follow up. Hypertension, encapsulated bleb, and more preoperative topical medications are associated with surgical failure.