Diurnal IOP variations similar in contralateral eyes

Variations of 24-hour IOP in the right and left eyes are similar, according to a study. However, the study authors said, the strength of the association between the two eyes at any single IOP measurement time was only moderate — “much weaker than what was thought previously.” Therefore, they said, “it may be difficult to perform a one-eye therapeutic trial using single pairs of right and left eye IOP measurements.”

John H.K. Liu, PhD, and colleagues at the Hamilton Glaucoma Center in San Diego, Calif., reviewed IOP data from 38 people between the ages of 18 and 25 years old and 53 people between the ages of 40 and 74 years old. IOP was measured every 2 hours in the sitting and supine positions and in the supine position during the 8 hours of sleep. Measurements were always taken in the right eye first.

For each age group, the profiles of IOP variations were similar in the two eyes with either the habitual body position or the 24-hour supine position. Mean, peak, and trough IOPs in the right eye were slightly higher than those in the left eye during the defined periods. There was no difference in the IOP ranges between the eyes, except for the supine IOP in the younger group during the diurnal period.

The study is published in the October issue of Ophthalmology.