Corneal irregularities such as higher-order aberrations (HOAs) often contribute to visual difficulties following penetrating keratoplasty (PK). A recent study investigated whether scleral lenses can counteract HOAs to improve visual performance in post-PK patients, and found substantial benefit is possible.
The prospective study included 38 eyes of 25 patients who underwent PK. The researchers measured uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), keratometry and wavefront analyses of HOAs with corneal topography in all patients before and after eight hours of scleral lens wear.
The team found that all patients demonstrated improved visual acuity with scleral lenses. Before scleral lens fitting, UCVA was 1.15log MAR, and BCVA was 0.84log MAR. They found that contact lens–corrected visual acuity decreased to 0.13log MAR.
With scleral lenses, all patients experienced significant decreases in spherical equivalence, cylinder and keratometry parameters, as well as anterior corneal HOAs, coma and astigmatism coefficients. The researchers noted that, based on the literature, the reduced endothelial cell density in the study group was similar in those who did not use scleral lenses after PK.
During the approximately 14-month follow-up period, one eye had a conjunctival prolapse and two eyes had graft rejection episodes. These patients resumed scleral lens wear after treatment for these complications.
The researchers concluded that their results support the safety and efficacy of scleral lenses as a treatment option for corneal astigmatism and HOAs associated with PK.
Penbe A, Kanar HS, Simsek S. Efficiency and safety of scleral lenses in rehabilitation of refractive errors and high order aberrations after penetrating keratoplasty. Eye Cont Lens. October 30, 2020. [Epub ahead of print].