Method for safer penetrating keratoplasty in patients with low scleral rigidity

In eyes with low scleral rigidity, penetrating keratoplasty (PKP) is a high-risk procedure because forward movement of the lens-iris diaphragm can result in prolapse of intraocular contents, expulsive choroidal hemorrhage, and damage to the crystalline lens. We developed a method for safer PKP in eyes with low scleral rigidity. In this technique, the host cornea is incompletely excised and remains attached at the 6 and 12 o'clock positions while the cardinal sutures to secure the donor button over the host are placed. Donor endothelium is protected by an intervening layer of viscoelastic material. After the first 3 cardinal sutures are placed, the host button is completely excised and removed and the donor cornea is sutured. This technique prevents the unopposed forward movement of the lens-iris diaphragm and may reduce the risk of expulsive choroidal hemorrhage and spontaneous extrusion or damage to the crystalline lens during PKP in patients with low scleral rigidity.