Novel Gonioscopy Score and Predictive Factors for Intraocular Pressure Lowering After Phacoemulsification

Abstract

Purpose:  To evaluate a novel gonioscopy score as a potential predictor for intraocular pressure (IOP) reduction after cataract surgery. Materials and Methods:  This was a prospective study that included consecutive patients with or without glaucoma, either with open or narrow angles but without peripheral anterior synechiae, who underwent phacoemulsification. Eyes with intraoperative complications and secondary glaucoma were excluded. A preoperative gonioscopy score was created, summing the Shaffer gonioscopy grading in 4 quadrants (range, 0 to 16). To determine variables associated with IOP change at 6 months, univariate and multivariate linear mixed-effects regression analysis was performed adjusting for age, sex, and preoperative IOP. Results:  In total, 188 eyes from 137 patients were enrolled. The mean age of the patients was 75.0 (±8.5) years and the average preoperative IOP was 15.6 (±3.6) mm Hg with 0.7 (range, 0 to 4) glaucoma medications. The mean IOP reduction after phacoemulsification was 3.0 (±2.6) mm Hg at postoperative month 6. After multivariate analysis, preoperative IOP [β=0.49 (0.41-0.58), Ptextless0.0001], gonioscopy score [β=−0.17 (−0.24 to −0.09), Ptextless0.0001], anterior chamber depth (ACD) [β=−0.88 (−1.64 to −0.14), P=0.02], and IOP/ACD ratio [β=0.45 (0.07 to 0.83) P=0.021] were associated with IOP reduction at 6 months. Conclusions:  Preoperative predictors for IOP reduction after cataract surgery were preoperative IOP, ACD, gonioscopy score, and IOP/ACD ratio. The IOP/ACD ratio and gonioscopy score can be easy parameters to obtain and may help clinicians to estimate the IOP reduction after phacoemulsification.