Doctors know intraocular pressure (IOP) rises at night and when the patient is in the supine position. To mitigate the effect on patients with glaucoma, and those at-risk, some doctors have proposed glaucoma patients sleep sitting upright. But one new study, published in the journal Acta Ophthalmologica is narrowing the glaucoma patient’s bedtime problem and touting the benefits of a new device. Evidently, the pillow patients use can spike their pressure.

In a simulated sleep position, the investigators said, turning the head into a pillow is associated with a clinically significant increase in estimated IOP. However, this elevation could be mitigated with the use of protective shielding in the form of glasses that sit on the orbital rim (although they point out that swimming goggles were not used since they have been associated with pressure increases in other studies). 

To establish the IOP levels, the team reviewed 11 patients using a specially developed epi-palpebral pressure sensor attached to an eyelid of the right eye. Participants included 11 patients with primary open-angle glaucoma and 11 healthy volunteers. The team took measurements in the simulated sleep position, both with and without the protective glasses. Epi-palpebral pressure was determined in each individual eye, and the estimated IOP was then inferred.

“This experimental study showed a large increase in the estimated IOPs with the head turned into the pillow, in the lower-positioned eye,” the report reads. “The data suggest that potentially harmful high IOP levels may therefore be reached while sleeping with a pillow, leading to progressive glaucomatous damage.”

However, when using the protective glasses, the subjects showed little to no increase in IOP. With the heads turned comfortably into the pillow, the mean IOP increased by an estimated 19.6mm Hg in the patient group and 28mm Hg in the control group. When the subjects wore the protective glasses, it decreased again by 16.3mm Hg in the patient group and 25.1mm Hg in the control.