Effect of Preoperative Factors and Gonioscopy on Intraocular Pressure Reduction after Phacoemulsification in Glaucoma

ABSTRACT

PURPOSE: To evaluate a new gonioscopy score and preoperative factors as a potential predictor for intraocular pressure (IOP) reduction after phacoemulsification. METHODS: This is a retrospective review of 182 eyes with glaucoma of either open or narrow angles that underwent phacoemulsification. Preoperative variables such as age, IOP, refractive errors, anterior chamber depth (ACD), axial length, and lens position were evaluated at 6 months after surgery. A preoperative gonioscopy score was created, summing the Shaffer gonioscopy grading in 4 quadrants. To determine variables associated with IOP change at 6 months, univariate and multivariate linear regression analysis was performed. RESULTS: The mean age of the patients was 72.8 ± 9.5 years and the average preoperative IOP was 16.4 ± 3.7 mmHg with 1.2 glaucoma medications. The mean IOP reduction after phacoemulsification was 2.7 ± 2.2 mmHg at postoperative 6 months. Preoperative IOP (β = 0.55, p < 0.001), gonioscopy score (β = −0.29, p < 0.001), ACD (β = −0.67, p = 0.02), and IOP/ACD ratio (β = 0.58, p = 0.01) were associated with IOP reduction at 6 months. CONCLUSIONS: Preoperative predictors for IOP reduction after phacoemulsification were preoperative IOP, ACD, gonioscopy score, and IOP/ACD ratio in patients with glaucoma. The IOP/ACD ratio and gonioscopy score can be easy parameters to obtain and may help clinicians to estimate the IOP reduction after phacoemulsification.