Product Code: ILSC2007_201

In Vivo and In Vitro Evaluation of Corneal Damage Induced by 1.57 µm Laser Radiation
Authors:
Daniel Courant, Commissariat à l'Energie Atomique; France
Catherine CHAPEL, Commissariat Energie Atomique; Fontenay aux roses France
Christophe POTHIER, Delegation Generale Armement; Arcueil France
Jean-Claude PEROT, Delegation Generale Armement; Arcueil France
Presented at ILSC 2007

A variety of infrared laser sources between 1500-1700 nm is called as "eye-safe". However, in providing protection for the deeper layers of the eye, the cornea is susceptible to thermal damage. The purpose of this study was first, to determine the threshold damage exposure on rabbit cornea induced by a 3 ns single pulse emitted at 1573 nm, using clinical observations and histology and to compare data to the current limit values. Secondly, it was suggested to investigate infrared cellular effects with biochemical techniques on cell cultures in order to specify a better understanding of laser-tissue interaction and corneal injury. The ED50 obtained with corneal beam diameter of 400 µm is 26.6 J.cm-2 and the corresponding radiant exposure, calculated with the recommended 1 mm aperture diameter, is 4.3 J.cm-2. Results support the present 1 J.cm-2 exposure limit but the safety margin is reduced. Preliminary assays realized in vitro have shown the possibility to use specifical tests at the cellular level. The frequency of apoptotic bodies seemed the most suitable criterion capable to reveal the cellular stress induced by laser exposure.