Clinical utility of Intraocular pressure monitoring outside of normal office hours in patients with glaucoma

Objective: To determine whether intraocular pressure (IOP) monitoring outside of normal office hours adds clinically useful information. Methods: We reviewed the records of all patients with glaucoma who were admitted for 24-hour IOP monitoring during 3 years. Applanation IOP was recorded in the sitting position from 7 AM until midnight and in the supine position at 6 AM. Results: Thirty-two patients (22 women and 10 men) were enrolled (mean +/- SD age, 67.3 +/- 12.1 years). Mean +/- SD 24-hour IOP was 13.0 +/- 2.2mmHg. Mean +/- SD peak 24-hour IOP (16.8 +/- 3.2 mm Hg) was significantly higher than peak office IOP (14.7 +/- 3.2mmHg) (P < .001). Peak IOP was recorded outside of office hours in at least 1 eye in 22 patients (69%). Mean IOP fluctuation during 24-hour monitoring (6.9 +/- 2.9 mm Hg) was significantly greater than that during office hours (3.8 +/- 2.3 mm Hg) (P < .001). Peak 24-hour IOP was higher than the peak IOP noted during previous office visits in 40 eyes (62%). Results of 24-hour IOP monitoring led to immediate treatment change in 23 eyes (36%). Conclusions: In glaucoma patients with advanced disease or progression that are disproportionate to known IOP measurements, 24-hour monitoring of IOP may reveal a greater role for pressure-related risk for glaucoma progression than previously suspected and may alter treatment strategies.