Objective: To evaluate the effect of phacoemulsification on intraocular pressure (IOP) in filtered eyes with primary angle closure glaucoma (PACG).
Methods: In this retrospective case series, 47 eyes from 47 PACG patients who previously had trabeculectomy were consecutively enrolled. All patients had visually significant cataracts and phacoemulsification was performed at least 3 months after trabeculectomy. The IOPs were recorded preoperatively, 1 day, 1 week, 2 weeks, 1 month, 3 months, 6 months, 12 months and 24 months after surgery. The best correct visual acuity (BCVA) , the number of glaucoma medications and the filtered bleb grade were recorded preoperatively and 24 months after phacoemulsification. IOP and BCVA before and after phacoemulsification were compared by student t test. The frequences of antiglaucoma medicine, bled grade and IOP control before and after phacoemulsification were compared by Mann-Whitney Test. Linear regression analysis, Pearson and Spearman were performed to assess the correlation between IOP change and other variants.
Results: IOP was decreased significantly from (18.7±6.7) mmHg (1 mmHg=0.133 kPa) at baseline to 16.4±2.0 mmHg at final follow-up (t=2.54, P=0.015) . The median number of glaucoma medications was significantly decreased (P<0.01) at 2 years postoperatively. The magnitude of IOP reduction was significantly correlated with preoperative IOP (r=0.95, P<0.01). BCVA (LogMAR) was improved significantly at month 24 (t=5.62, P<0.01). Filtered bleb decreased insignificantly at 2 years postoperatively (P=0.113). Complete success, qualified success and failure rates in terms of IOP were 61.7%, 27.7% and 10.6% before surgery , 89.4%, 8.5%, 2.1% at 2 years postoperatively. In 29 patients with preoperative IOP≤21 mmHg, mean IOP increased insignificantly from (14.5±4.0) mmHg to (15.5 ± 2.3) (P=0.195) at 2 years. In the 18 patients with preoperative IOP> 21 mmHg, mean IOP decreased from (25.3 ± 4.4) mmHg preoperatively to (17.8 ± 2.4) mmHg (P<0.01).
Conclusions: Phacoemulsification reduces IOP and the number of glaucoma medications in previously filtered PACG eyes. The IOP remained normal in normal tension eyes after phacoemulsification in filtered PACG eyes but decreased significantly in hypertensive eyes.