title: Retinal endoilluminator toxicity of xenon and light-emitting diode (LED) light source: rabbit model.
abstract: OBJECTIVE
  This study evaluates retinal toxicity due to endoillumination with the light-emitting diode (LED) light source in comparison to endoillumination with xenon light source.
  
  
  METHODS
  Twenty-five eyes of 14 New Zealand pigmented rabbits were used in the study. The LED light (Omesis Medical Systems, Turkey) group was composed of 7 right eyes, while the other 7 right eyes constituted the xenon group (420 nm filter, 357mW/cm(2)) (Bright Star; DORC, Zuidland, Netherlands). Eleven untreated left eyes composed the control group. Twenty gauge pars plana incision 1.5 mm behind the limbus was performed in the right eyes. Twenty gauge bullet type fiberoptic endoilluminator was inserted into the eye from the incision without any pars plana vitrectomy. Fiberoptic endoilluminator was placed in such a way that it was directed toward visual streak of the rabbit retina with a 5 mm distance to retinal surface. Endoillumination was then applied for 20 min with a maximum light intensity for LED and xenon light. In left control eyes, no surgical procedure and no endoillumination were performed. One week after the endoillumination procedure, both eyes of the rabbits were enucleated following electroretinography. Sections stained with hematoxylin and eosin to evaluate morphologic changes. Retina tissues were assessed by active caspase-3 staining.
  
  
  RESULTS
  There was no difference in the shape of the waveforms recorded in the eyes endoilluminated with LED light and xenon light sources compared to control eyes both before and after endoillumination application (p > 0.05). Microscopic evaluation of the retinas with hematoxylin and eosin staining demonstrated that all study groups have normal histologic properties similar to control group. No apoptosis positive cells were found within all sections in all groups.
  
  
  CONCLUSIONS
  When the LED light source is used with maximum power and limited duration for endoillumination in rabbit eyes it does not produce phototoxic effects that may be detectable by electrophysiology and histology similar to xenon light.
authors.affiliation: Department of Ophthalmology, Faculty of Medicine, Gazi University , Ankara , Turkey .
authors.forename: Bahri
authors.initials: B
authors.lastname: Aydin
authors.forename: Erdem
authors.initials: E
authors.lastname: Dinç
authors.forename: S Necat
authors.initials: SN
authors.lastname: Yilmaz
authors.forename: U Emrah
authors.initials: UE
authors.lastname: Altiparmak
authors.forename: Fatma
authors.initials: F
authors.lastname: Yülek
authors.forename: Sevda
authors.initials: S
authors.lastname: Ertekin
authors.forename: Mustafa
authors.initials: M
authors.lastname: Yilmaz
authors.forename: Mehmet
authors.initials: M
authors.lastname: Yakın
mesh_terms: D000818:Animals; D053148:Caspase 3 / Q000378:metabolism; D004596:Electroretinography; D008027:Light; D011817:Rabbits; D012160:Retina / Q000033:anatomy & histology / Q000201:enzymology / Q000528:radiation effects*; D014978:Xenon
chemical_list: D014978:Xenon; D053148:Caspase 3
keywords: Endoillumination; LED; light emitting diode; phototoxicity; retina; xenon