Effects of intraocular epinephrine on the corneal endothelium of rabbits

Epinephrine is frequently used in the phacoemulsification to dilate pupils. To determine the effects of different concentration of epinephrine on the corneal endothelial cells, twenty-eight rabbit eyes were equally divided into four groups. Solutions, which contained normal saline, 1:1000 epinephrine, 1:5000 epinephrine and 1:10000 epinephrine respectively, were injected into the anterior chambers of the eyes of four groups of rabbits. In vivo morphological changes of corneal endothelium and changes of thickness were checked with specular microscopy. In vitro morphological evaluation of corneal endothelium was observed in excised corneal buttons stained with alizarin red with trypan blue, and with scanning electron microscopy. Our results showed that there was no significant difference in cell density and corneal thickness among the four groups. Alizarin red with trypan blue stain and SEM exam revealed smooth and distinct cell borders of endothelial cells in each group. Intracameral injection of epinephrine does not produce toxic effect on corneal endothelial cells in rabbits.