Experimental Model to Quantify the Retinal Phototoxicity of Two Different Wavelengths During Vitreoretinal Surgery

Abstract

 

Purpose:

 

To quantify the retinal phototoxicity of two different wavelengths (420 and 435 nm) in simulated macula light expose surgery.

 

Methods:

 

An experimental study was conducted using pigmented rabbit eyes. Five eyes were exposed to a xenon light source with 23-gauge endolaser probe to simulate a macula surgery using 24 lumens of radiance. The animals were divided in two groups. In the first one (two animals), the right eye was exposed to a 420 nm wavelength, and in the second (three animals), the right eye was exposed to a 435 nm wavelength, both with focal illumination guided by one rabbit optic disc area.The ambient, body and eye temperatures were measured at baseline, 10, 20 and 30 minutes, using a laser thermometer.Electroretinogram (ERG), color fundus photo, optical coherence tomography (OCT) and Fluorescein Angiography (FA) were performed at the baseline, seven and 30 days after the procedure. After that, the animals suffered eutanasia then the eyes were removed and fixed in formol saline solution for histological analysis.

 

Results:

 

Our results demonstrated ERG, FA and OCT thickness alterations after one week and 30 days in all eyes. Eyes exposed with 420nm were observer a atrophy of the retina demonstrated by the OCT and the EPR damage by the FA, comparing to the 435 nm group.

 

Conclusions:

 

This study demonstrated important retinal and RPE damage in pigmented rabbits eyes exposed with the most common a xenon wavelight. Furthers studies with a higher numbers of eyes and different wavelenghts should be done.  

 

 

Keywords: vitreoretinal surgery