Purpose: To evaluate the safety and feasibility of patent blue (PB) as the vital dye in Descemet membrane endothelial keratoplasty (DMEK).
Methods: Bovine corneal endothelial cells were incubated with different concentrations (0.02%-2.5%) of PB. The cell viability, which was assessed by Cell Counting Kit-8 assay, was compared with that of untreated control and 0.06% to 0.4% trypan blue. The dyes were also used for graft preparation and implantation in the porcine eye model to evaluate stain quality, dye retention, and the feasibility of using PB in DMEK surgery.
Results: No obvious increase in cytotoxicity was detected for 0.06% to 0.4% trypan blue and PB at concentrations up to 1.0%, but the cell viability after incubating with 1.5% to 2.5% PB was significantly reduced. PB at 0.5% to 1.0% generated good staining quality that can be used to facilitate graft implantation. Although the staining quality of 0.5% to 1.0% PB faded to an intermediate level after a 30-minute wash in phosphate-buffered saline, dye retention persisted for up to 24 hours.
Conclusions: PB at 0.5% to 1.0% is biocompatible and can stain the graft sufficiently, making it an alternative for DMEK surgery.