Corneal scissors are used to excise the corneal button. These beveled scissors have sharp cutting edges and are designed with an angle and a radius of curvature to cut within the trephination groove and produce a perpendicular or slightly inwardly beveled incision. Host corneal excision is carried out the full 360 degrees. Gentle traction with 0.12 mm tissue forceps may be used to help maintain position of the host button while cutting. Care is taken not to undercut the wound as this may result in difficulty with watertight wound closure or increased astigmatism.