Intraocular pressure (IOP) is the most important and only modifiable risk factor for the development and worsening of glaucoma over time. However, despite years of research, it is not entirely clear what aspects of IOP are most important in determining whether a patient’s glaucoma will worsen – IOP varies according to the circadian rhythm (over 24 hours each day) and while some research suggests the average IOP is most important, other data suggest that spikes in IOP or wide fluctuations are most harmful. All glaucoma treatments (including eye drops, lasers, and operating room surgery) reduce a patient’s risk of vision loss from glaucoma by lowering IOP.

Therefore, some may question whether isolated IOP measurements taken in the eye doctors office only a few times per year provide enough information to adequately monitor patients with glaucoma or make informed decisions about treatment. While the vast majority of patients with glaucoma “stabilize” with treatment (meaning they stop losing vision), a subset of patients continues to worsen.

We hypothesize that disease worsening can be partly explained by IOP that is above the patient’s “safe zone” only at certain times when the doctor might not be able to readily measure the patient’s eye pressure. Indeed, it is known that some patients exhibit their highest IOP late at night or first thing in the morning. We believe that new technologies that enable patients to measure their eye pressure in the comfort of their own homes may provide important information on glaucoma risk and aid in treatment plans.

We are using remote home tonometry to measure patients’ eye pressures at all times of the day and night for extended periods of time. Being doing so, we hope to gain insights into:

• patterns of IOP fluctuations that predispose patients to worsening of their glaucoma
• treatments that effectively blunt fluctuations and spikes in eye pressure
• risk factors for exceptionally high IOP spikes or fluctuation