Comparison between intraocular pressure profiles over 24 and 48 hours in the diagnosis of glaucoma

Abstract Purpose: To assess the additional value of 48-hour diurnal-nocturnal IOP profiles in comparison to only 24-hour diurnal-nocturnal IOP profiles in the management of glaucoma.Methods: All diurnal-nocturnal IOP profiles over 48 hours that were taken between 2017 and 2019 for diagnostic purposes in glaucoma patients at our hospital were reviewed. We counted elevated IOP values (>21 mmHg), higher short-term IOP fluctuations (> 6 mmHg) and nocturnal IOP peaks (measured at midnight and at 7 AM in supine position). In a second step, we repeated this analysis in the same profiles but censored the data to the first 24-hours. We compared the outcome rates by means of the Chi2-Test. Results: 661 IOP profiles were included. 59% of 48-hour IOP profiles revealed IOP values above 21 mmHg and 87% showed IOP fluctuation greater than 6 mmHg. Nocturnal peaks in supine position could be observed in 51% of the patients. In the profiles censored to the first 24 hours, the fractions were 50%, 71% and 48%, (p < 0,01, p < 0,01 and p = 0,12) respectively. Conclusion: Our data suggest that 48-hour diurnal-nocturnal IOP profiles are superior in identifying patients with clinically meaningful IOP events in comparison to observing the patients for only 24-hours. It is likely that the higher accuracy is worth the additional socioeconomic costs resulting from the prolonged inpatient stay.