10/06/2026
Penetrating Keratoplasty (PK)
What are you looking at?
Image 1: PK graft secured with a running suture.
Image 2: PK graft with 16 interrupted sutures.
Image 3: PK graft with 24 interrupted sutures.
Image 4: PK graft with a combination of running & interrupted sutures.
Image 5: A crystal clear PK graft 30 years after the procedure.
PK is a full-thickness transplant procedure in which a trephine is used to make a full-thickness resection of the patient's cornea, followed by the placement of a full-thickness donor corneal graft. Interrupted and/or running sutures are then placed radially at equal tension to minimize post-operative astigmatism. Later, the sutures are selectively removed to reduce the amount of astigmatism present.
PKs are performed primarily for visually significant stromal scarring, opacities with an uncertain status of the endothelium or significant posterior corneal involvement, corneal ectasia (such as keratoconus and pellucid marginal degeneration), combined stromal and epithelial disease, and infectious or non-infectious corneal ulcerations or perforations.
(Donaghy CL, Vislisel JM, Goins KM, Greiner MA. An Introduction to Corneal Transplantation. May 21, 2015; Available from: https://eyerounds.org/tutorials/cornea-transplant-intro/)