NEW YORK (Reuters Health) – Measurements of intraocular pressure (IOP) may depend on which eye is measured first, according to a new study published in the Archives of Ophthalmology. The finding could have clinical implications, especially in the treatment of patients with glaucoma, the authors say.

Some previous studies have suggested that the IOP of the right eye is higher than that of the left eye. However, the authors note that this difference may not reflect which eye actually has a higher IOP, but rather which eye physicians traditionally measure first.

The current study, led by Dr. Melike Pekmezci of the University of California, San Francisco involved 105 healthy volunteers with a mean age of about 40 years that were randomized between two groups. All participants underwent a series of two IOP measurements in one eye, two in the other eye, and two again in the original eye. Those in the first group had the first measurement taken in their right eye; in the second group, the examiner started with the left eye. Two weeks later, at a similar time of day, all participants returned to have the same set of IOP measurements, but starting in the opposite eye.

Examiners also measured the central corneal thickness of each participant