Risk Factors for Hyphema After Trabeculectomy With Mitomycin C

PURPOSE:To determine the risk factors for hyphema after trabeculectomy with mitomycin C (MMC). PATIENTS AND METHODS:In total, 420 patients (420 eyes) with glaucoma who underwent trabeculectomy with MMC between June 1, 2005 and December 31, 2010 at Kumamoto University Hospital, Japan, were retrospectively evaluated. Hyphema after trabeculectomy was defined as the niveau formed by bleeding in the anterior chamber. Logistic multivariable analysis was applied to determine the risk factors for hyphema. RESULTS:Of the 420 patients, 104 (24.8%) had hyphema. Neovascular glaucoma [NVG; odds ratio (OR)=2.404; P=0.0017] and anticoagulant or antiplatelet medication at trabeculectomy (OR=2.143; P=0.0274) were significant risk factors for hyphema. Of the 108 NVG patients, 43 (39.8%) had hyphema after trabeculectomy with MMC. In the subgroup analysis of NVG patients, neovascularization in the anterior chamber angle at trabeculectomy (OR=5.7886; P=0.0163) and anticoagulant or antiplatelet medication at trabeculectomy (OR=3.3325; P=0.0450) were risk factors for hyphema, whereas preoperative intravitreal bevacizumab injection significantly reduced the hyphema risk (OR=0.3568; P=0.0275). CONCLUSIONS:The risk factors for hyphema after trabeculectomy with MMC are independently associated with NVG and anticoagulant or antiplatelet medication. Neovascularization in the anterior chamber at trabeculectomy and anticoagulant or antiplatelet medication enhance the risk of hyphema developing in NVG patients, whereas preoperative injection of intravitreal bevacizumab reduces the likelihood.