Use of trypan blue dye during conversion of deep anterior lamellar keratoplasty to penetrating keratoplasty

We describe a technique that uses trypan blue dye to identify residual recipient corneal stroma and Descemet membrane (DM) during conversion of deep anterior lamellar keratoplasty (DALK) to penetrating keratoplasty (PKP). After the host cornea is dissected, trypan blue dye (0.06%) is used to highlight the remaining host corneal stroma and DM, if any. In 8 DALK procedures that had to be converted to PKP because of DM perforation, trypan blue staining identified remnants of DM and parts of the posterior corneal stroma in 7 eyes. Improved visualization of the residual host tissue enabled complete excision and an overall optimal recipient wound profile.