Intraocular Pressure Elevation within the First 24 Hours after Cataract Surgery in Patients with Glaucoma or Exfoliation Syndrome

Objective To investigate whether eyes with glaucoma or exfoliation syndrome without glaucoma are prone to exhibit intraocular pressure (IOP) elevation shortly after cataract surgery and, if so, whether timolol maleate 0.5% reduces these spikes. Design Prospective randomized double-masked clinical trial. Participants One hundred twenty-two patients with normal eyes, medically well-controlled glaucoma, or exfoliation syndrome who underwent uneventful phacoemulsification cataract extraction. Methods Patients were randomly assigned to an immediately postoperative drop of either timolol maleate 0.5% or no treatment. Intraocular pressure was measured preoperatively and 4, 8, and 24 hours and 1 week later. Main Outcome Measures Intraocular pressure measurements. Results The changes in postoperative IOP over time differed significantly between glaucoma, exfoliation syndrome, and normal ( P = 0.005). Intraocular pressure was significantly lower in the normal group (n = 25) than in both the glaucoma (n = 18) and exfoliation syndrome (n = 19) groups ( P 25 mmHg and > 30 mmHg occurred in 10 (55%) and 5 (28%) glaucoma patients, respectively, and 5 (27%) and 2 (11%) exfoliation syndrome patients, respectively. Timolol maleate 0.5% eliminated IOP spikes > 30 mmHg and reduced the frequency of IOP > 25 mmHg in both groups to 14% in the glaucoma group and 5% in the exfoliation syndrome group. Most IOP elevation occurred at 4 hours postoperatively. The mean IOP was 30 mmHg, but IOP elevation below that level can still occur.