Endothelin-1 Concentration in Aqueous Humor Predicts Postoperative Late Low Intraocular Pressure in Primary Open-angle Glaucoma After Trabeculectomy

Background: This study aimed to evaluate the potential risk factors for postoperative late low intraocular pressure (IOP) in patients with primary open-angle glaucoma (POAG) after trabeculectomy. Materials and Methods: Adult patients who were diagnosed with POAG and scheduled to undergo primary unilateral trabeculectomy in our hospital were consecutively included. Blood samples before the surgery and aqueous humor samples during the surgery of each participant were collected. Patient demographics, preoperative assessments, and laboratory tests were compared in patients with or without late low IOP. The risk factors for late low IOP were evaluated using logistic regression modeling. The predictive value of endothelin-1 (ET-1) in aqueous humor for late low IOP was evaluated by receiver operating characteristic curve analysis. Results: Thirty-nine of 222 enrolled patients were cases of late low IOP with an incidence of 17.6% (39/222). The multivariate logistic regression analysis indicated that ET-1 concentration in aqueous humor was the only independent risk factor for late low IOP after trabeculectomy (odds ratio, 0.89; 95% confidence interval, 0.79-0.98; P=0.021). Receiver operating characteristic curve analysis showed that ET-1 concentration in aqueous humor was a predictor for late low IOP after trabeculectomy with an area under the curve of 0.639, a specificity of 84.62%, and a sensitivity of 39.89%, respectively (P=0.006). Conclusions: Our study indicated that ET-1 concentration in aqueous humor was an independent risk factor for late low IOP in patients with POAG after trabeculectomy.