Effect of optic material on posterior capsule opacification in intraocular lenses with sharp-edge optics: randomized clinical trial

Ophthalmology. 2005 Jan;112(1):67-72. doi: 10.1016/j.ophtha.2004.07.032.


Purpose: Comparison of the intensity of posterior capsule opacification (PCO) between a silicone intraocular lens (IOL) and a hydrophobic acrylic IOL, both of them 3-piece and open-loop and having truncated optics with sharp edges.

Design: Randomized, controlled, patient- and examiner-masked trial with intrapatient comparison.

Participants and controls: One hundred six eyes of 53 patients with age-related bilateral cataract.

Methods: Each patient had cataract surgery in both eyes and received a silicone IOL in one eye and a hydrophobic acrylic IOL in the fellow eye. Follow-up examinations were at 1 and 3 years after surgery. The patients were examined at the slit lamp, visual acuity (VA) was assessed, and standardized high-resolution digital retroillumination images of the posterior capsule were taken. The amount of PCO was assessed subjectively at the slit lamp and objectively using automated image analysis software. Data of 56 eyes of 28 patients, who were examined at each follow-up, were analyzed.

Main outcome measure: Posterior capsule opacification intensity at 3 years as measured with automated image analysis.

Results: At 1 and 3 years after surgery, PCO did not differ between the silicone (1.6 and 1.9 [image analysis scores, 0-10 scale], respectively) and acrylic IOLs (1.7 and 2.2) (P > 0.24). Furthermore, there was no significant difference in best-corrected VA, rhexis/IOL overlap, capsular folds, and amount of anterior capsule opacification during the follow-up period. In each group, one neodymium:yttrium-aluminum-garnet (YAG) laser capsulotomy was performed during the entire study duration.

Conclusion: Silicone and hydrophobic acrylic are similarly effective in inducing the PCO-inhibiting effect of a rectangular, sharp optic edge. Three years after surgery, the PCO intensity and the YAG rate were low with both IOL models.

Publication types

  • Clinical Trial
  • Comparative Study
  • Randomized Controlled Trial

MeSH terms

  • Acrylic Resins
  • Aged
  • Biocompatible Materials*
  • Cataract / prevention & control*
  • Double-Blind Method
  • Follow-Up Studies
  • Humans
  • Lens Capsule, Crystalline / pathology*
  • Lens Implantation, Intraocular
  • Lenses, Intraocular*
  • Phacoemulsification
  • Postoperative Complications / prevention & control*
  • Prosthesis Design
  • Silicone Elastomers
  • Visual Acuity


  • Acrylic Resins
  • Biocompatible Materials
  • Silicone Elastomers