Effect of Phacoemulsification on Anterior Chamber Angle in Eyes with Medically Uncontrolled Filtered Primary Angle-Closure Glaucoma

PURPOSE: To evaluate the effect of phacoemulsification and intraocular lens (IOLs) implantation in eyes with medically uncontrolled primary angle-closure glaucoma (PACG) previously treated with trabeculectomy and to quantify the anatomical changes in the anterior chamber angle by ultrasound biomicroscopy (UBM). METHODS: Forty-four eyes of 37 consecutive patients with medically uncontrolled PACG coexisting cataracts with a surgical history of trabeculectomy were included in this study. Each patient underwent phacoemulsification and IOL implantation. Indentation gonioscopy and UBM were performed preoperatively and then again 3 months after surgery. The main outcome measures were best-corrected visual acuity (BCVA), intraocular pressure (IOP), number of antiglaucoma medications and anatomical changes in the anterior chamber angle. RESULTS: The mean logarithm of the minimum angle of resolution BCVA significantly improved from 0.52 ± 0.30 preoperatively to 0.26 ± 0.23 postoperatively (p < 0.001). The mean IOP significantly decreased from 24.33 ± 9.65 mmHg preoperatively to 18.04 ± 7.86 mmHg postoperatively (p < 0.05). 001). The median number of antiglaucoma medications decreased from 2 preoperatively to 1 postoperatively (p < 0.001). There was no significant difference in the extent of peripheral anterior synechia after the surgery (p > 0.05). Some parameters, including anterior central chamber depth, angle opening distance at 500 μm, trabecular-iris angle, and scleral ciliary process angle, were significantly higher after than before surgery (p < 0.001). However, the crystalline lens rise was significantly smaller following the surgery (p < 0.001). CONCLUSIONS: Phacoemulsification and IOL implantation reduced the IOP and improved vision in eyes with medically uncontrolled filtered PACG. The mechanism underlying the outcomes observed following surgery might be related to the anterior chamber deepening, widened drainage angle, and improved aqueous fluid flow to the trabecular meshwork.