1Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom
2Aston University, Birmingham, United Kingdom
3Optegra UK, Manchester, United Kingdom
4Manchester Royal Eye Hospital, Manchester, United Kingdom
Commercial Relationships: Hema Radhakrishnan, None; Amit N. Jinabhai, None; Clare O'Donnell, None; Cindy Tromans, None
Purpose:To assess visual performance and higher-order ocular aberrations in keratoconic patients using toric soft contact lenses (SCL), rigid-gas-permeable (RGP) contact lenses and spectacle lens correction.
Methods:Twenty-two keratoconus patients (16 RGP lens wearers and 6 spectacle wearers) were fitted with toric SCL. Ocular aberrations were measured with and without the patients habitual RGP lenses and with the SCL in place. In the spectacle wearers, aberrations were measured with and without the SCL. Visual performance (high- and low-contrast visual acuity) was evaluated with the patients habitual correction and with the SCL.
Results:Both the habitual lenses and the toric SCL significantly reduced coma, trefoil, 3rd-order, 4th-order cylinder and higher-order root-mean-square (RMS) aberrations (p 0.015) in RGP lens wearers. In the spectacle wearers the toric SCL significantly reduced coma, 3rd-order and higher-order RMS aberrations (p 0.01). The patients habitual RGP lenses gave better low-contrast acuity (p 0.006) compared to the toric SCL; however, no significant difference was found between lens types for high-contrast acuity (p = 0.10). No significant differences in visual performance measurements were found between the patients spectacles and the toric SCL (p 0.06) in spectacle lens wearers.
Conclusions:The results show that RGP lenses provided superior visual performances and greater reduction of 3rd-order aberrations compared to toric SCL in this group of keratoconic patients. In the spectacle-wearing group, visual performance with the toric SCL was found to be comparable to that measured with spectacles. Nonetheless, with the exception of spherical aberration, the toric SCL were successful in significantly reducing uncorrected higher-order aberrations.
Keywords: keratoconus contact lens aberrations
© 2012, The Association for Research in Vision
and Ophthalmology, Inc., all rights reserved. Permission to republish any
abstract or part of an abstract in any form must be obtained in writing
from the ARVO Office prior to publication.