Abstract
Abstract: :
Purpose: Intravitreal indocyanine green (ICG) application during retinal surgery has been associated with severe damage on the retinal pigment epithelium. However, the physiological background of these findings remains to be assessed. Methods: In bovine RPE choroid preparations maintained in Ussing chambers, the effect of apical and basolateral application of ICG at different concentrations was evaluated. The electrophysiological parameters (transepithelial potential, tissular resistance, and short circuit current) were continuously monitored. The time of survival was plotted against the concentration of ICG in the apical or basolateral bath. The experiments were conducted either in daylight or dark–adapted conditions. Results: After apical application of ICG, all bioelectrical parameters were affected in a dose dependant manner. Similarly, the survival time decreased with increasing concentration of ICG in the apical bath. No significant changes were observed when the preparations were exposed to daylight. In case of basolateral application of ICG, any significant changes neither in bioelectrical parameters nor in the survival time were observed. Conclusions: The electrophysiological results of apical ICG application may explain that its toxic effect is exclusively observed with peroperative intravitreal application whereas no negative effects have been described when it is administered intravenously. Further work is necessary to identify the precise cellular mechanisms of these findings.
Keywords: drug toxicity/drug effects • electrophysiology: non–clinical • retinal pigment epithelium