May 2008
Volume 49, Issue 13
Free
ARVO Annual Meeting Abstract  |   May 2008
Higher-Order Aberrations From Posterior Corneal Surface in Patients With Keratoconus
Author Affiliations & Notes
  • T. Nakagawa
    Department of Ophthalmology, Osaka University Medical School, Suita, Japan
  • N. Maeda
    Department of Ophthalmology, Osaka University Medical School, Suita, Japan
  • Y. Hori
    Department of Ophthalmology, Osaka University Medical School, Suita, Japan
  • T. Inoue
    Department of Ophthalmology, Osaka University Medical School, Suita, Japan
  • M. Saika
    Technical Research Institute, Topcon Corporation, Tokyo, Japan
  • Y. Hirohara
    Technical Research Institute, Topcon Corporation, Tokyo, Japan
  • T. Mihashi
    Technical Research Institute, Topcon Corporation, Tokyo, Japan
  • Y. Tano
    Department of Ophthalmology, Osaka University Medical School, Suita, Japan
  • Footnotes
    Commercial Relationships  T. Nakagawa, None; N. Maeda, None; Y. Hori, None; T. Inoue, None; M. Saika, Topcon Corporation, E; Y. Hirohara, Topcon Corparation, E; T. Mihashi, Topcon Corporation, E; Y. Tano, None.
  • Footnotes
    Support  Grant 18591919 from the Japanese Ministry of Education, Science, Sports, and Culture, Tokyo, Japan.
Investigative Ophthalmology & Visual Science May 2008, Vol.49, 1032. doi:https://doi.org/
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      T. Nakagawa, N. Maeda, Y. Hori, T. Inoue, M. Saika, Y. Hirohara, T. Mihashi, Y. Tano; Higher-Order Aberrations From Posterior Corneal Surface in Patients With Keratoconus. Invest. Ophthalmol. Vis. Sci. 2008;49(13):1032. doi: https://doi.org/.

      Download citation file:


      © ARVO (1962-2015); The Authors (2016-present)

      ×
  • Supplements
Abstract

Purpose: : To measure the higher-order aberrations (HOA) caused by the posterior corneal surface in patients with keratoconus and to compare it to that in normal eyes.

Methods: : Twenty-eight keratoconic eyes and 24 normal control eyes were studied. The anterior and posterior corneal elevation and pachymetric data were obtained with a rotating Scheimpflug camera. (Pentacam Oculus, Wetzlar.) Higher-order aberrations for 6-mm pupils were calculated separately for the anterior and posterior corneal surfaces from the differences between the elevation data and the best-fit sphere. The refractive index of the cornea and aqueous humor were 1.376 and 1.336, respectively. The reference axes of the measurements were aligned with the primary line of sight. The magnitudes, axes of trefoil, and coma were calculated by vector analysis.

Results: : The mean corneal total HOAs, trefoil, coma, and spherical aberration due to anterior/posterior surface (root mean square, µm) were significantly higher in the keratoconic eyes (4.38/1.10, 0.775/0.194, 3.57/0.857, and 1.16/0.344) than in normal control eyes (0.461/0.146, 0.090/0.048, 0.337/0.076, and 0.090/0.037; Mann-Whitney Rank Sum test, P ≤0.001), respectively. The mean axes of the coma caused by the anterior surface (81.2 degrees) and the posterior surface (253.2 degrees) were in opposite directions.

Conclusions: : The corneal higher-order aberrations in keratoconic eyes were higher than in control eyes not only on the anterior surface but also on the posterior surface. The coma caused by the anterior corneal surface is compensated for, in part, by the coma due to the posterior corneal surface. The residual irregular astigmatism in keratoconic eyes wearing rigid gas-permeable contact lens can be estimated with the direct measurement of the HOA due to posterior corneal surface.

Keywords: topography • keratoconus • aberrations 
×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×