Review of the measurement and management of 24-hour intraocular pressure in patients with glaucoma

Elevated intraocular pressure (IOP) is a major, and currently the only, modifiable risk factor that has been shown to reduce the risk of glaucoma onset and progression. Diurnal measurements of IOP, usually during office hours, are commonly used for the assessment of IOP variation and the relative success of medical, laser, or surgical IOP-lowering interventions. Such measurements, however, fail to capture variation in IOP over the day/night cycle, which may be influenced by factors such as body position. We examine current evidence in the field of IOP measurement and control—with a focus on 24-hour (circadian) study design and measurement techniques and the 24-hour efficacy of current treatments—in patients with glaucoma and ocular hypertension. We then provide our recommendations for the design of future studies of circadian IOP with the aim of improving the assessment, management, and treatment of patients with glaucoma and ocular hypertension.