Home Tonometry Diurnal Intraocular Pressure Patterns, Patient Adherence, and Measurement Reliability in a Prospective Clinical Cohort.

Purpose: Assess patient adherence, diurnal intraocular pressure patterns, and correlation with in-office tonometry of home intraocular pressure monitoring (IOP).

Patients and methods: In this prospective cohort study, 75 patients with open-angle disease (150 eyes) were recruited and loaned the iCare HOME2 tonometer (ICH2) after in-person training and instructed to take 6 measurements per day for 10 ± 4 days. Statistical analysis of adherence, diurnal IOP patterns, and correlation with in-office tonometry was conducted.

Results: Most patients had good adherence (65% of patients took ≥ 6 measurements per day, median 7.4 measurements/day). However, adherence was poor for a notable minority of patients (19% of patients took less than 2 measurements per day). Patients with low adherence reported difficulty obtaining measurements and desire for more training with the ICH2 device. ICH2 identified diurnal patterns of IOP fluctuation: IOP varied significantly over the 24-hour day (p < 0.0001), and early morning peak IOP at 3 AM decreased significantly throughout the day to minimum mean IOP at 10 PM (p < 0.0001). IOP variance was significantly greater outside of clinic hours (p < 0.0001) and 36% of patients had maximum IOP outside of clinic hours. In-office IOP measurements had significant positive correlation to the closest ICH2 measurement obtained by the patient in time for both Goldman applanation (r² = 0.35, p < 0.0001) and iCare IC100 (r² = 0.48, p < 0.0001).

Conclusion: ICH2 is clinically useable and effective for detecting out-of-office IOP spikes, diurnal IOP patterns, and IOP variation.