Now that scleral lenses are back in vogue, researchers are busy trying to update their assessment of this modality’s risk profile. Recent findings of a group from the Université de Montréal may provide cause for concern: intraocular pressure during scleral lens wear may be increased by an average of 5mm Hg, regardless of the lens diameter.
A prospective randomized study conducted with 21 Caucasian subjects (16 female, five male) evaluated the variation of IOP during scleral lens wear and the influence of lens diameter. Researchers compared one eye randomly fitted with a 15.8mm diameter scleral lens to the fellow eye fitted with an 18mm lens of the same design, thickness and material. Anterior segment tomography was taken pre- and post-lens removal.
In those wearing the 15.8mm lens, transpalpebral IOP (IOPt) rose from 10.1 ±1.9mm Hg to 14.4 ±5.5mm Hg after 4.5 hours, while those fitted with the 18mm lens saw IOPt rise from 9.2 ±2.1mm Hg to 14.4 ±4.8 mm Hg. Researchers found the difference based on time, but not on the lenses, to be statistically significant.
Anterior segment parameters did not vary except for the anterior chamber volume and the corneal thickness. Baseline Goldmann-correlated IOP (IOPg) revealed no significant diurnal variations.
Researchers concluded that more work is needed to confirm if practitioners should be warned when using scleral lenses on populations at risk for glaucoma.
|Michaud L, Samaha D, Giasson CJ. Intra-ocular pressure variation associated with the wear of scleral lenses of different diameters. Cont Lens Ant Eye. July 24, 2018. [Epub ahead of print].|