title: Late postoperative complication of the foldable lens implantation: opacification of the intraocular lenses.
abstract: OBJECTIVE
  To analyze the cause of the late postoperative opacification of the lens optic of implanted intraocular lens (IOL).
  
  
  METHODS
  Twenty-two foldable hydrophilic acrylic lenses with opacification of their optics in 19 patients were taken out of the eye by surgery and examined by gross examination and microscopy. The lenses were stained with alizarin red and von Kossa method (special stains for calcium). Some were submitted for energy dispersive X-ray spectroscopy and scanning electron microscopy. The same kind of transparent IOLs were examined as the control group.
  
  
  RESULTS
  Granular deposits of variable sizes were revealed on the surface and within the lens optics. The deposits that were stained positive with alizarin red and von Kossa method showed the presence of calcium. Energy dispersive X-ray spectroscopy demonstrated the calcium and the phosphate present in the deposits. The distribution of the granules was dense in the central part of the optic and sparse at its periphery. There were negative findings in the haptics of the lenses taken out and the control lenses.
  
  
  CONCLUSIONS
  The cause of the opacification of the foldable lens optics is the deposits that consist of calcium and phosphate occurring inside and on the surface of the optics.
authors.affiliation: Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China (Email: danyinz@hotmail.com)
authors.forename: Danying
authors.initials: D
authors.lastname: Zheng
authors.forename: Yu
authors.initials: Y
authors.lastname: Lin
authors.forename: Zhenping
authors.initials: Z
authors.lastname: Zhang
authors.forename: Weirong
authors.initials: W
authors.lastname: Chen
authors.forename: Wenhui
authors.initials: W
authors.lastname: Yang
mesh_terms: D020878:Device Removal; D006801:Humans; D019654:Lens Implantation, Intraocular; D007910:Lenses, Intraocular; D018918:Phacoemulsification; D011183:Postoperative Complications; D011475:Prosthesis Failure