Toric collagen copolymer phakic intraocular lens to correct myopic astigmatism in eyes with pellucid marginal degeneration

J Cataract Refract Surg. 2012 Feb;38(2):256-61. doi: 10.1016/j.jcrs.2011.08.040.


Purpose: To evaluate the clinical outcomes of implantation of the Implantable Collamer Lens collagen copolymer toric phakic intraocular lens (pIOL) to correct myopic astigmatism in eyes with mild pellucid marginal degeneration (PMD).

Setting: Gimbel Eye Centre, Calgary, Alberta, Canada.

Design: Retrospective chart review.

Methods: All consecutive cases with PMD that had implantation of the toric pIOL from January 1, 2003, to May 30, 2011, were retrospectively reviewed for postoperative outcomes. Perioperative variables of interest included uncorrected (UDVA) and corrected (CDVA) distance visual acuities, manifest refraction, and corneal topography.

Results: The study comprised 10 eyes of 5 patients. The mean age was 37.4 years ± 2.6 (SEM). The mean CDVA was 0 ± 0.03 logMAR (20/20) preoperatively and -0.04 ± 0.03 logMAR (20/18) postoperatively. The mean postoperative UDVA was +0.14 ± 0.05 logMAR (20/28). The mean spherical equivalent (SE) was -6.71 ± 0.9 diopters (D) preoperatively and -0.58 ± 0.1 D at the last follow-up. All eyes had improved CDVA after surgery. One patient reported severe glare and halos in 1 eye postoperatively, requiring removal and replacement of the toric pIOL because of a hyperopic refractive surprise. The new toric pIOL was subsequently repositioned because of high residual astigmatism related to changes in corneal topography postoperatively and a small shift in the position of the toric pIOL. The final manifest refraction for this eye was plano -1.00 × 160.

Conclusions: Implantation of the collagen copolymer toric pIOL was a safe, effective surgical procedure for the correction of myopic astigmatism in eyes with mild PMD.

MeSH terms

  • Adult
  • Astigmatism / physiopathology
  • Astigmatism / surgery*
  • Collagen / chemistry*
  • Corneal Dystrophies, Hereditary / physiopathology
  • Corneal Dystrophies, Hereditary / surgery*
  • Corneal Topography
  • Female
  • Humans
  • Lens Implantation, Intraocular*
  • Male
  • Middle Aged
  • Myopia / physiopathology
  • Myopia / surgery*
  • Phakic Intraocular Lenses*
  • Polymers / chemistry
  • Refraction, Ocular / physiology
  • Retrospective Studies
  • Treatment Outcome
  • Visual Acuity / physiology
  • Young Adult


  • Polymers
  • Collagen