Título / Title

EXPERIMENTAL MODEL TO EVALUATE THE BENEFITS OF LIGHT-EMITTING DIODE (LED) SOURCE TO PREVENT RETINAL PHOTOTOXICITY DURING PARS PLANA VITRECTOMY

Introdução / Purpose

To evaluate retinal phototoxicity generated by light-emitting diode (LED) source during vitreoretinal surgery.

Material e Método / Methods

Prospective cross-sectional study in pigmented and albino rabbit eyes exposed to LED vitreoretinal surgery lighting simulations. Thirty-two rabbits were divided into four groups exposed to two different LED filters and compared to xenon wavelength light sources (420nm and 475nm). Color fundus photo, Optical Coherence Tomography (OCT) and fluorescein angiography (FA) were performed before and after surgery to quantify the retinal damage. Histologic study was performed in all exposed eyes.

Resultados / Results

The maximum intensity of the light sources and endoillumination probe did not exceed those used commercially. All pigmented animals were submitted to the experiment had some degree of phototoxicity regardless of light source. Retina damage was evident as the FA presented areas of hyperfluorescence, OCT disclosed increase reflective areas of the inner and/or outer retina layers and RPE and histology show some disorganization of the retinal layers. White LED and 475nm wavelength had minor degree damage in pigmented rabbits when compared to others lighting simulations group. Albino rabbits had no phototoxicity, except xenon 420nm filter group.

Discussão e Conclusões / Conclusion

The use of LED as light source for endoillumination in pars plana vitrectomy shows similar retinal damage compare to the others light sources. Thermal irradiation and photochemical toxicity expose to the EPR is prone to the injury. EPR can absorbers light from different wavelengths and still a roll player to generate retinal toxicity.

Palavras Chave

LED, Phototoxicity, Xenon Light, Pars Plana Vitrectomy