Article Text

Clinical science
Surgically induced astigmatism after posterior chamber phakic intraocular lens implantation
  1. K Kamiya1,
  2. K Shimizu1,
  3. D Aizawa1,
  4. A Igarashi1,
  5. M Komatsu2
  1. 1
    Department of Ophthalmology, University of Kitasato School of Medicine, Kanagawa, Japan
  2. 2
    Department of Ophthalmology, Sanno Hospital, Tokyo, Japan
  1. Correspondence to Dr K Kamiya, Department of Ophthalmology, University of Kitasato School of Medicine, 1-15-1 Kitasato, Sagamihara, Kanagawa, 228-8555, Japan; kamiyak-tky{at}


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

Methods: Seventy-three eyes of 47 patients undergoing ICL implantation through a horizontal 3.0 mm clear corneal incision were retrospectively examined. The amount of corneal astigmatism before and 3 months after surgery using an automated keratometer (ARK-700A, Nidek) and corneal topography (ATRAS995, Carl Zeiss Meditec) were quantitatively investigated. 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) dioptres (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.

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  • Competing interests KS is a consultant to STAAR Surgical.

  • Patient consent Obtained.

  • Provenance and peer review Not commissioned; externally peer reviewed.

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