Cataract Surgery in Eyes with Filtered Primary Angle Closure Glaucoma

Purpose: To evaluate the effect of cataract surgery on intraocular pressure (IOP) in filtered eyes with primary angle closure glaucoma (PACG). Methods: In this prospective interventional case series, 37 previously filtered eyes from 37 PACG patients with mean age of 62.1±10.4 years were consecutively enrolled. All patients had visually significant cataracts and phacoemulsification was performed at least 12 months after trabeculectomy. Visual acuity, IOP and the number of glaucoma medications were recorded preoperatively, and 1, 3, 6 and 12 months after surgery. Anterior chamber (AC) depth was measured preoperatively and 3 months after cataract surgery with A-scan ultrasonography. The main outcome measure was IOP at 12 months. Results: IOP was decreased significantly from 18.16±5.91 mmHg at baseline to 15.37±2.90 mmHg at final follow-up (P<0.01). The mean number of glaucoma medications was significantly decreased from 1.81±0.24 to 0.86±1.00 (P=0.001) at 1 year postoperatively. At final follow up, 36 (97.2%) eyes and 32 (86.4%) eyes had IOP≤21 and IOP≤18 mmHg, respectively; 14 (37.8%) eyes and 9 (24.3%) eyes had IOP≤21 and IOP≤18 mmHg without medications, respectively. The magnitude of IOP reduction was correlated with higher preoperative IOP (r=0.85, P<0.001), shallower preoperative AC depth (r=-0.38, P=0.01) and greater changes in AC depth (r=-0.39, P=0.01). Conclusion: Cataract surgery reduces IOP and the number of glaucoma medications in previously filtered PACG eyes. This reduction seems to be greater in patients with higher preoperative IOP and shallower anterior chambers.