title: Effect of ultraviolet B radiation on the absorption characteristics of various intraocular lenses.
abstract: BACKGROUND
  The aim of this study was to determine the effect of ultraviolet B (UVB) exposure on UV filters of various intraocular lenses (IOLs).
  
  
  METHODS
  Eight samples each of the hydrophobic acrylic, hydrophilic acrylic and silicone IOLs were used. Four IOLs of each type was selected randomly as the control group while the remaining four IOLs of each type were exposed to a UVB dose of 1.4 J/cm(2) (2.40 mW/cm(2)) for 9.45 min, two times with a 4-week interval. IOLs were evaluated for any sign of opacification under microscope weekly. After a follow-up period of 16 weeks, spectrometry for UV filter absorption rates, scanning electron microscopy for deposit formation and energy dispersive X-ray analysis for elemental composition were performed for all IOLs, and findings of the control group IOLs were compared with those of the UVB-exposed IOLs. All these procedures were done at the Department of Ophthalmology, Faculty of Medicine, Dokuz Eylul University.
  
  
  RESULTS
  All the IOLs were free of any opacification during the follow-up period. Spectrometric analysis of their UV filters revealed a change in absorption rates in the hydrophilic acrylic and silicone IOLs compared to the control IOLs of the same type. Only the hydrophobic acrylic IOLs preserved the same UV absorption curve after UVB exposure.
  
  
  CONCLUSIONS
  The pathogenesis of IOL opacification is still undetermined. Some reports claimed that the UV light was the responsible factor. Our experimental study revealed that high doses of UVB did not cause any opacification though they impaired the function of UV filters of the hydrophilic acrylic and silicone IOLs.
authors.affiliation: Department of Ophthalmology, Dokuz Eylul University, Izmir, Turkey. nkocak@yahoo.com
authors.forename: Nilufer
authors.initials: N
authors.lastname: Kocak
authors.forename: Suleyman
authors.initials: S
authors.lastname: Kaynak
authors.forename: Turna
authors.initials: T
authors.lastname: Ilknur
authors.forename: Sebnem
authors.initials: S
authors.lastname: Ozkan
authors.forename: Gokhan
authors.initials: G
authors.lastname: Erdogan
authors.forename: Guray
authors.initials: G
authors.lastname: Cingil
mesh_terms: D000180:Acrylic Resins; D004577:Electron Probe Microanalysis; D007910:Lenses, Intraocular; D008855:Microscopy, Electron, Scanning; D011475:Prosthesis Failure; D011830:Radiation Effects; D012826:Silicone Elastomers; D013056:Spectrophotometry, Ultraviolet; D014466:Ultraviolet Rays
chemical_list: D000180:Acrylic Resins; D012826:Silicone Elastomers