Wearing scleral contact lenses could increase a patient’s intraocular pressure (IOP), a recent study, presented this week at ARVO, shows. To gauge the effect of these lenses on IOP, researchers from the University of the Incarnate Word’s School of Optometry in San Antonio, Texas, fit seven individuals with normal corneas and IOP levels with a scleral lens in one eye and a soft lens in the other eye. The subjects wore the lenses for eight hours and researchers compared pre-wear IOP measurements with post-wear measurements.

In the scleral lens eye, IOP increased notably in all subjects after eight hours of wear. While IOP did increase slightly in some of the soft lens eyes, it decreased in others; overall, the changes in these eyes were not significant. Additionally, the study ruled out lens settling as a possible cause of IOP changes in the scleral lens eyes.

“Because scleral contact lenses place all of their weight on the white part of the eye [… ] some believe that they might cause the fluid to back up in the eyes, resulting in high pressure inside the eye or glaucoma,” the study said.

“After eight hours of wear, the scleral lens group showed a significant increase in IOP of 5.81 +/- 1.62mm Hg,” says Joseph P. Shovlin, OD, of Scranton, PA. “Long-term effects should be considered and examined in patients who might be susceptible to optic nerve changes due to IOP increases. Careful follow-up in all scleral lens patients should include IOP assessment on a regular basis.”