rss
Br J Ophthalmol doi:10.1136/bjo.2009.160044
  • Clinical Science

Surgically Induced Astigmatism after Posterior Chamber Phakic Intraocular Lens Implantation

  1. Kazutaka Kamiya1,
  2. Kimiya Shimizu1,
  3. Daisuke Aizawa1,
  4. Akihito Igarashi1,
  5. Mari Komatsu2
  1. 1 University of Kitasato School of Medicine, Japan;
  2. 2 Department of Ophthalmology, Sanno Hospital, Japan
  1. * Corresponding author; email: kamiyak-tky{at}umin.ac.jp
  • Received 18 February 2009
  • Accepted 30 May 2009
  • Published Online First 18 August 2009

Abstract

Aim: To assess astigmatism induced after phakic intraocular lens (Visian ICLTM, STAAR Surgical) implantation.

Methods: We retrospectively examined seventy-three eyes of 47 patients undergoing ICL implantation through a horizontal 3.0-mm clear corneal incision. We quantitatively investigated the amount of corneal astigmatism before and 3 months after surgery using an automated keratometer (ARK-700A, Nidek) and corneal topography (ATRAS995TM, Carl Zeiss Meditec). The surgically induced astigmatism was assessed by vector analysis using the Holladay-Cravy-Koch formula.

Results: The corneal astigmatism was significantly increased from 1.10 ± 0.51 diopters (D) to 1.44 ± 0.57 D using the keratometer (Wilcoxon signed-rank test, p<0.001). It was also significantly increased from 1.16 ± 0.53 D to 1.45 ± 0.57 D using corneal topography (p<0.001). On the other hand, the manifest astigmatism was significantly decreased from 0.93 ± 0.60 D to 0.72 ± 0.58 D (p<0.001). The surgically induced astigmatism was 0.45 ± 0.26 D at an axis of 93.3° using the keratometer and 0.49 ± 0.26 D at an axis of 98.0° using corneal topography.

Conclusions: ICL implantation induces corneal astigmatism through a with-the-rule astigmatic shift of approximately 0.5 D, which was small but not negligible for candidates for refractive surgery.

Footnotes

    Relevant Article

    Register for free content


    Free sample
    This recent issue is free to all users to allow everyone the opportunity to see the full scope and typical content of BJO.
    View free sample issue >>

    Don't forget to sign up for content alerts so you keep up to date with all the articles as they are published.