Anterior segment parameters as predictors of intraocular pressure reduction after phacoemulsification in eyes with open-angle glaucoma

Abstract

Purpose  To evaluate intraocular pressure (IOP) change after cataract surgery in eyes with open-angle glaucoma (OAG) and its relationship to angle and anterior segment parameters measured by anterior segment optical coherence tomography (AS-OCT). Setting  University of California, San Francisco, California, USA. Design  Prospective case series. Methods  Eyes were placed into a narrow-angle group or open-angle group based on gonioscopy grading. Biometric parameters were measured using AS-OCT (Visante) preoperatively, and IOP 4 months after surgery was obtained. The IOP change and its relationship to AS-OCT parameters were evaluated. Results  Eighty-one eyes of 69 patients were enrolled. The mean age of the patients was 76.8 years. The preoperative IOP was 15.02 mm Hg on 1.89 glaucoma medications. The average mean deviation of preoperative visual field was −4.58 dB. The mean IOP reduction was 2.1 mm Hg (12.8%) from a preoperative mean of 15.0 mm Hg. The IOP reduction was significantly greater in eyes with narrow angles than in eyes with open angles (20.4% versus 8.0%) (P = .002). In multivariate analysis, preoperative IOP (β = −0.53, P textless .001, R2 = 0.40), angle-opening distance at 500 mm (β = 5.83, P = .02, R2 = 0.45), angle-opening distance at 750 mm (β = 5.82, P = .001, R2 = 0.52), and lens vault (β = −0.002, P = .009, R2 = 0.47) were associated with IOP reduction postoperatively. Conclusion  In eyes with OAG, IOP reduction after cataract surgery was greater in eyes with narrower angles. Preoperative IOP, angle-opening distance, and lens vault were predictors for IOP reduction.