Abstract
Abstract: :
Purpose:To compare the on–eye measured higher order aberrations of different hydrogel contact lens modalities including one with aspheric optics to compensate for spherical aberration. Methods:In this study, five contact lens designs were investigated including: Biomedics 55 Premier (Ocular Sciences, Inc), Frequency 55 Aspheric (Coopervision), Focus Night & Day (Ciba Vision), Acuvue 2 (Vistakon), and Focus Dailies (Ciba Vision). Two eyes of an individual patient were investigated with each eye fitted and measured for the five categories of contact lenses. The patient’s best spectacle corrected visual acuity was 20/20 OU with manifest refraction of –3.25 DS OU. All contact lenses used were –3.25 DS OU. Each eye was examined and deemed as healthy without ocular surface abnormality. Dilation was achieved using tropicamide 1.0% and phenylephrine 2.5%. The contact lens was allowed to settle on the eye for 15 minutes before being examined for proper fit. Wavefront measurements were obtained using the Alcon LADARWave (Fort Worth, TX) wavefront sensing device. Five wavefront measurements were obtained for each lens. A composite wavefront measurement was determined by taking an average of the three readings in closest agreement. The higher order aberrations measured were coma, spherical aberration, and other terms. The category other terms includes: trefoil, secondary astigmatism and tetrafoil. Results:In all five lens designs, an average increase was measured in coma and spherical aberration. Two lenses, Focus Night & Day (Ciba Vision) and Acuvue 2 (Vistakon) had an average decrease in other terms. Conclusions:Wavefront sensing technology is an objective means at measuring ocular aberrations in patients wearing contact lenses. Contact lens designs to compensate for some higher order aberrations need clinical validation to prove their effectiveness. Although the sample size in this study was small, on average, all contact lens designs increased ocular aberrations compared to those measured without a contact lens.