Modern highly oxygen-permeable nonfenestrated scleral lenses induce approximately 1 to 2% corneal edema after short periods of lens wear in healthy individuals. This study investigated the magnitude and regional variation in scleral lens-induced central corneal edema after penetrating keratoplasty.
The purpose of this study was to examine the magnitude and regional variation in corneal edema after a short period of scleral lens wear in post–penetrating keratoplasty eyes and a control group of eyes with healthy corneas.
Nine post–penetrating keratoplasty eyes (nine participants; mean age, 32 years) were fitted with highly oxygen-permeable nonfenestrated scleral lenses (Dk 100 × 10−11 cm3 O2 (cm)/[(s) (cm2) (mmHg)]). Central corneal thickness was measured using Scheimpflug imaging before lens insertion and immediately after lens removal (mean wearing time, 6.2 hours). Corneal edema was quantified across the central 6 mm and compared with data obtained from a historical control group of healthy eyes using a similar experimental paradigm.
Post–penetrating keratoplasty eyes exhibited significant corneal edema after lens wear (2.99% [95% confidence interval, 1.13 to 4.85%]) averaged across the central 6 mm (P = .006) and regional variations in edema (P < .001) (greater swelling toward the graft-host junction inferiorly). Compared with healthy eyes, post–penetrating keratoplasty eyes displayed a greater magnitude of corneal edema (by ~3×) and greater variability in the corneal response (by ~2.5×).
Scleral lens–induced central corneal edema is greater in post–penetrating keratoplasty eyes and varies regionally compared with healthy corneas after short-term wear. Lens design and fitting factors contributing to hypoxic and mechanical corneal stress should be carefully considered for all post–penetrating keratoplasty scleral lens fits to minimize potential graft rejection or failure in the longer-term.