Effect of Phacoemulsification on Intraocular Pressure in Healthy Subjects and Glaucoma Patients

Background: We investigated how cataract surgery might influence long-term intraocular pressure (IOP) change in both healthy subjects and glaucoma patients. Methods: A retrospective analysis of patients who had had clear corneal phacoemulsification with a minimum of 12 months of follow up was performed. Glaucoma patients with medically controlled open-angle glaucoma and healthy subjects with no glaucoma were included in the analysis. The change of IOP after phacoemulsification and factors associated with postoperative IOP change were investigated. Results: In total, 754 eyes of 754 patients, specifically 106 patients with glaucoma and 648 patients with no glaucoma (i.e., healthy subjects) were enrolled. The phacoemulsification effected a reduction of IOP: 1.03 +/- 3.72 mmHg in healthy subjects and 1.08 +/- 3.79 mmHg in glaucoma patients at postoperative 1 year (P= 0.656). There were negative coefficients of IOP until 1 year of follow up (all P < 0.001), but the IOP change gradually showed a less steeply decreasing slope (correlation coefficient: -0.993), compared with those for 1 week and 1 month of follow up (correlation coefficients: -1.893 and -1.540, respectively). In the multivariate analysis, age and preoperative IOP showed significant associations with postoperative IOP change (regression coefficients: -0.034 and 0.419 respectively, all P< 0.001). Conclusion: Phacoemulsification resulted in IOP reduction, which effect regressed in healthy subjects and glaucoma patients over the course of long-term follow up. Therefore, long-term monitoring of IOP change is needed. In cases of higher preoperative IOP and young patients, phacoemulsification alone is a reliable option for IOP control.