Role of intraocular pressure measurement on the day of phacoemulsification cataract surgery

PURPOSE: To determine whether measurement of intraocular pressure (IOP) preoperatively or in the early postoperative period is an accurate predictor of raised IOP 24 hours after cataract surgery. SETTING: Department of Ophthalmology, Queen's Medical Centre, Nottingham, United Kingdom. METHODS: This prospective study comprised 101 eyes of 101 patients having phacoemulsification cataract surgery. The IOP was measured by Goldmann applanation tonometry preoperatively and 2 to 3 hours, 6 to 8 hours, and 22 to 24 hours postoperatively. The relationship between the same-day and next-day IOP readings was examined. RESULTS: One hundred patients completed the study. The IOP at 22 to 24 hours was significantly correlated with the IOP preoperatively (correlation coefficient r] 0.54; 95% confidence interval CI], 0.38-0.67) and at 6 to 8 hours (r = 0.56; 95% CI, 0.41-0.68). In contrast, the IOP measurement at 2 to 3 hours correlated relatively poorly with the next-day IOP (r = 0.33; 95% CI, 0.14-0.49). Twelve patients had an IOP of 26 mm Hg or higher at 22 to 24 hours. The risk of this outcome increased significantly with higher IOP values preoperatively and, to a lesser extent, with a raised IOP at 6 to 8 hours. Glaucoma and ocular hypertension were associated with a 2.9-fold increased risk (95% CI, 0.67-12.8) of a next-day IOP of 26 mm Hg or higher. CONCLUSIONS: Preoperative IOP or a diagnosis of glaucoma or ocular hypertension were significant risk factors for raised next-day IOP after small-incision phacoemulsification. It may be possible to select patients at greater risk of prolonged ocular hypertension before surgery for prophylactic IOP-lowering treatment. This would minimize patient morbidity and reduce the number of patients requiring next-day review, resulting in significant health economic savings.