title: Evaluation of the safety of xenon/bandpass light in vitrectomy using the A2E-laden RPE model.
abstract: BACKGROUND
  The purpose of the study was to investigate the brightness of the xenon/bandpass light in vitrectomy and assess its phototoxic effects using A2E-laden retinal pigment epithelial (RPE) cells.
  
  
  METHODS
  The total luminous flux and spectral irradiance of 20- and 25-gauge endoilluminators connected to xenon lamps were measured and compared to those of 20- and 25-gauge endoilluminators connected to a halogen lamp. In vitro, A2E-laden cells were evenly exposed to xenon/bandpass light for 5 to 30 min positioned at 1 cm and 2 cm for a standard light probe and an implantable "chandelier" light probe, respectively, above the cells, and the cell viability was assessed using WST-1 assay. The cell viability was compared with cells exposed to 30 min of halogen light projected through a 20-gauge endoilluminator.
  
  
  RESULTS
  The maximal total luminous flux of xenon/bandpass light emitted through the 20-gauge endoilluminator was 2.8 times higher than that of the halogen light. The total luminous flux of the 25-gauge endoilluminators was 0.6-1.1 times greater than the 20-gauge endoilluminators connected to the halogen light. The viability of the A2E-laden cells after exposure to the xenon/bandpass light was no different than that of the cells exposed to the halogen light when the total luminous flux of these lights was at the same level. Xenon/bandpass light from an implantable "chandelier" light probe induced A2E-mediated RPE damage to a similar extent as that of the halogen light through a 20-gauge endoilluminator.
  
  
  CONCLUSIONS
  A2E-mediated phototoxicity of xenon/bandpass light is comparable to that of halogen light.
authors.affiliation: Department of Ophthalmology, University of Tokyo School of Medicine, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan. yanagi-tky@umin.ac.jp
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Yanagi
authors.forename: Aya
authors.initials: A
authors.lastname: Iriyama
authors.forename: Woo-Dong
authors.initials: WD
authors.lastname: Jang
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Kadonosono
mesh_terms: D002470:Cell Survival / Q000528:radiation effects; D002478:Cells, Cultured; D006801:Humans; D008027:Light / Q000009:adverse effects*; D008029:Lighting / Q000295:instrumentation; D010777:Photochemistry; D010857:Pigment Epithelium of Eye / Q000378:metabolism / Q000473:pathology / Q000528:radiation effects*; D011726:Pyridinium Compounds / Q000378:metabolism / Q000528:radiation effects*; D012176:Retinoids / Q000378:metabolism / Q000528:radiation effects*; D014821:Vitrectomy / Q000295:instrumentation*; D014978:Xenon
chemical_list: C112040:A2-E (N-retinylidene-N-retinylethanolamine); D011726:Pyridinium Compounds; D012176:Retinoids; D014978:Xenon