Keratoconus patients who wear scleral lenses for eight hours a day for one month can expect improved dry eye symptoms, subjective vision and comfort, according to a recent study. However, the study also found that tear film surface quality was worse after contact lens wear after the same period.
Researchers in Madrid evaluated the anterior surface of 49 keratoconus patients—19 with intrastromal corneal ring segments (ICRS) and 30 without. Tear break-up time was reduced in both groups by 2.23s after scleral lens wear. Ocular surface disease index and corneal staining improved signiﬁcantly in both groups as well. Measuring subjective vision and comfort with visual analog scale revealed both were better after scleral lens wear in all patients.
Anterior corneal surface tear film surface quality (TFSQ) values increased in both groups after one month of scleral wear and were significant; however, there were no statistical differences for the TFSQ values in a month. Also, the ocular surface in both groups showed worse wettability after removing the scleral lens.
The TFSQ values for the keratoconus patients with ICRS was worse compared with the group without ICRS, which researchers attributed to the segments implanted in the stroma provoking corneal surface modifications and molding the anterior surface. The study also suggests that the worse wettability in both groups after removing the scleral lens could be due to the osmotic diﬀerence between the corneal epithelium and saline solution to ﬁll the lens, even inducing a corneal epithelium bogging in some cases.
Serramito M, Privado-Aroco A, Batres L, Carracedo GG. Corneal surface wettability and tear film stability before and after scleral lens wear. Cont Lens Anterior Eye. April 6, 2019. [Epub ahead of print].