Comparison of optical aberrations in keratoconus with scleral versus rigid gas permeable lenses

Abstract

Purpose to assess optical aberrations under scleral (SL) versus rigid gas permeable (RGP) lenses in patients with keratoconus. Methods A prospective study including 25 eyes of 14 patients. The best-corrected visual acuity (BCVA) with corrective glasses, RGP and SL, stage of keratoconus (Amsler-Krumeich classification), minimum pachymetry, maximum keratometry, and corneal higher-order aberrations (i.e, total HOAs, coma, and trefoil) with RGP and with SL were collected. Aberrometry was performed using iTrace® aberrometer (Tracey Technologies, USA). Results 80% of the included keratoconus patients were stage 4, with a mean age of 34.3 years (±8.8). There were no significant differences in mean BCVA (logMAR) between SL and RGP. The mean BCVAs were significantly better both with SL (p < 0.0001) and RGP (p < 0.0001) compared with corrective glasses. Total HOAs (p = 0.01), coma (p = 0.003) and trefoil (p = 0.008) were significantly lower with SL compared with RGP. The BCVA decreased with the stage of keratoconus in SL (p = 0.01) and RGP (p = 0.02). The BCVA decreased with decreasing minimum pachymetry in SL (p = 0.02) and RGP (p = 0.002), and with increasing maximum keratometry in SL (p = 0.02) and RGP (p = 0.01). Significant correlations were found between BCVA, total HOAs (p = 0.008), and coma (p = 0.02) in SL. Conclusion For the same keratoconus patients, total higher order, coma and trefoil optical aberrations were reduced with scleral lenses compared to rigid gas permeable lenses.