Evaluation of equine corneal endothelium after exposure to 0.5% indocyanine green - in vitro study

The purpose of the study was to investigate whether indocyanine green (ICG) dye damages the corneal endothelium of horses. Twenty-four corneas of 12 healthy equines, males or females, of different ages were used in this study. Only eyes with no ocular findings were used. Randomly, one eye was included in the treatment group and one in the control group. The eyes of the treatment group were exposed for 1 minute to dye ICG 0.5%. After that the endothelium of all eyes was stained with trypan blue and alizarin red S and analyzed and photographed under an optical microscope. Areas with damaged endothelial cells were manually measured and quantified using software for morphometric analysis and expressed as a percentage of cell damage. In all eyes examined areas of cell damage were observed in both corneas of the control group and the treatment group. The mean endothelial damage was 0.8 ± 0.37% in the treatment group and 0.97 ± 0.39% in the control. The Qui-square test stated that treatment and control group were not different. The ICG 0.5% did not cause acute damage to equine corneal endothelium.