Strategies to Estimate the Characteristics of 24-Hour IOP Curves of Treated Glaucoma Patients During Office Hours

Purpose:To verify whether office-hour measurements in patients in different body positions can estimate the characteristics of 24-hour intraocular pressure (IOP) in treated POAG patients. Methods:The 24-hour IOP curves of 86 eyes of patients with treated glaucoma (19 treated with Timolol, 29 with Latanoprost, 16 with Dorzolamide, 10 with Brimonidine and 12 with the fixed combination Dorzolamide/Timolol) were analyzed. Measurements were taken at 9 AM; 12, 3, 6, and 9 PM; and 12, 3, and 6 AM, both in the supine (TonoPen XL) and sitting (Goldmann tonometer) positions. Peak, mean, and fluctuation of 24-hour IOP curves were compared with office-hour measurements obtained in subjects in the sitting position alone and combining pressures obtained in the sitting and supine positions (four measurements in each body position from 9 AM to 6 PM). The percentage of subjects with estimates of all IOP parameters within a cutoff of +/-1 (peak and mean) and +/-2 mm Hg (fluctuation) was calculated. Results:Office-hour sitting measurements correctly identified peak, mean, and IOP fluctuation in 25-40% of the patients compared with 17-34% for the combination of supine and sitting measurements. Still the strategy of supine+sitting measurements was clinically useful: 14 cases with partial characterization at sitting position were fully characterized using supine+sitting measurements, whereas 3 cases with no characterization at sitting position became partially characterized using supine+sitting measurements. 10 cases were correctly characterized by both strategies; 1 case was not characterized by any strategy. Conclusions:Office-hour sitting measurements correctly identified peak, mean, and IOP fluctuation in 25-40% of the patients compared with 17-34% for the combination of supine and sitting measurements. Still the strategy of supine+sitting measurements was clinically useful: 14 cases with partial characterization at sitting position were fully characterized using supine+sitting measurements, whereas 3 cases with no characterization at sitting position became partially characterized using supine+sitting measurements. 10 cases were correctly characterized by both strategies; 1 case was not characterized by any strategy.