PK is a full-thickness transplant procedure, in which a trephine of an appropriate diameter is used to make a full-thickness resection of the patient's cornea, followed by placement of a full-thickness donor corneal graft.
The initial step in penetrating keratoplasty should be the preparation of the donor tissue. The use a corneal button 0.25-0.50mm larger than the diameter of the host corneal openning is recommneded as it can help reduce excessive postoperative corneal flattening, reduce the risk of secondary glaucoma and enhance wound closure.
Penetrating Keratoplasty with interrupted and running sutures, 1st postoperative day.
The host cornea is trephined, the anterior chamber is filled with viscoelastic and the the donor tissue is placed endothellial side down on the recipient's eye. The cornea is then sutured in place with either interrupted or continuous sutures. Interrupted sutures are preferred in vascularized, inflammed or thinned corneas as well as in pediatric cases.
Penetrating keratoplasty may be combined with cataract surgery, secondary intraocular lens implantation, glaucoma surgery and retinal surgery.