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% Cl, 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% Cl, 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% Cl, 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.