Vital staining of corneal endothelium.

The efficacy and applicability of dual vital staining of human and porcine corneal endothelium with trypan blue and alizarin red S stains was investigated. Exposure of endothelial cells to different concentrations of these two dyes for varying periods of time revealed that 0.3% solution of trypan blue for 1 minute followed by 0.2% solution of alizarin red S (pH 4.2) for 1/2 to 1 minute was the most useful technique to assess the cell viability, micro to macro damage, cell division and cell counts, etc. Alizarin red S dye should not be used in in vivo evaluation, while trypan blue was very effective to evaluate the endothelial viability of donor cornea just prior to keratoplasty.