Impact of Scleral Lens on Corneal Curvature and Pachymetry in Keratoconic Eyes.

Abstract

The aim of this study was to evaluate the influence of scleral lens on corneal curvature and corneal thickness in keratoconic patients. Scheimpflug imaging was captured before lens insertion, immediately after removal at 6 hours, and, again, the next day morning. Anterior flat, steep, and maximal keratometry (Kflat, Ksteep, and Kmax, respectively) and pachymetry values were compared. Minimal corneal flattening was observed for all 3 curvature parameters immediately after lens removal but was not statistically significant. The average Kflat was 0.28 ± 0.31 (D) flatter (P = 0.37), Ksteep was 0.37 ± 0.09 (D) flatter (P = 0.11), and Kmax was 0.19 ± 0.24 (D) flatter (P = 0.53), which returned to baseline level after one night of lens removal. After 6 hours of a 16-mm scleral lens wear, central corneal pachymetry showed that a marginal thickening of 7.76 ± 3.00 μm (P = 0.06) was causing 1.77 ± 0.67% of corneal edema, which returned to baseline after one night of lens removal. There was no significant correlation noted between corneal flattening and change in corneal thickness (r = 0.09, P = 0.78) and between central corneal clearance and change in corneal curvature (r = -0.23, P = 0.51). Minimal transient alteration in the anterior corneal curvature and corneal thickness was observed after 6 hours of scleral lens wear. These temporary changes regressed to baseline after overnight discontinuation of the lens.