Short-term repeatability of diurnal intraocular pressure patterns in glaucomatous individuals

To evaluate the short-term repeatability of diurnal intraocular pressure (IOP) patterns in eyes with primary open-angle glaucoma (POAG).

Observational cohort study.

Forty-seven subjects with treated POAG.

Subjects underwent assessment of IOP using Goldmann tonometry every 2 hours from 0800 to 2000 on 2 visits 1 week apart. Intervisit agreement of IOP by time point and of IOP change between time points was assessed using intraclass correlation coefficients (ICCs).

Diurnal IOP patterns.

Between-visit agreement of IOP values at each time point was generally fair to good, with ICCs ranging from 0.45 to 0.71 in right eyes and from 0.51 to 0.71 in left eyes. Between-visit agreement of IOP change over time periods between time points was uniformly poor, with ICCs ranging from -0.08 to 0.38 in right eyes and from -0.11 to 0.36 in left eyes.

Treated POAG patients do not manifest a repeatable diurnal IOP pattern from day to day when measured by Goldmann tonometry. Measurement of single-day IOP variation poorly characterized short-term IOP variation.