Effect of intraoperative factors on IOP reduction after phacoemulsification

The purpose of the study was to determine the independent predictors of long-term intraocular pressure (IOP) reduction after cataract surgery with phacoemulsification. This is a retrospective review of uncomplicated cataract surgeries from 2006 to 2008 at the Baltimore VA Medical Center with longitudinal follow-up. Demographic, clinical, biometric, and intraoperative variables including phacoemulsification parameters were recorded. Univariate and multivariate linear regression were used to analyze the relationship between these variables and postoperative IOP, which was the outcome variable. Analysis was performed in 115 eyes of 115 patients who underwent uncomplicated phacoemulsification during the study period. There was an average postoperative IOP reduction through 12, 24, and 36 months of −1.7 ± 3.1, −1.5 ± 3.8, and −1.3 ± 2.6 mmHg, respectively. Higher preoperative IOP (P < 0.001), a more anterior relative lens position (P < 0.05), and longer phaco time (P < 0.05) were significantly associated with greater postoperative decrease in IOP using univariate analysis. Using multivariate analysis, preoperative IOP (P < 0.001), and phaco time (P = 0.038) were associated with greater postoperative IOP reduction through 24 months. Phaco time is independently associated with IOP reduction after adjusting for age and preoperative IOP. Higher preoperative IOP is associated with a greater IOP-lowering effect after phacoemulsification.