The Penetrating Keratoplasty (PKP): A Century of Success

Abstract

Besides routine postoperative follow-up, the prophylaxis of complications in penetrating keratoplasty (PKP) includes special preoperative and intraoperative aspects. Preoperative prophylaxis consists of the therapy of systemic diseases and eyelid abnormalities, determining individual optimal graft size, avoiding PKP in cases of uncontrolled intraocular pressure, avoiding PKP in cases of acute corneal hydrops, pretreatment of vascularized cornea, amniotic membrane transplantation before PKP in cases of ulcerative keratitis, quality-controlled organ-cultured transplants, and preoperative counseling by the microsurgeon to ensure patient compliance. Intraoperative prophylaxis consists of controlled arterial hypotension and complete relaxation during general anesthesia and application of a Flieringa ring in aphakic vitrectomized eyes. Precautions for intraoperative prophylaxis of astigmatism must be followed. A measurable improvement seems to be possible using the technique of nonmechanical trephination of patient and donor from the epithelial side using the excimer laser but not the femtosecond laser. Graft size should be adjusted individually (“as large as possible, as small as necessary”). Limbal centration should be preferred over pupil centration (especially in keratoconus). In addition to the situation-specifi c diagnosis and preoperative planning, the critical selection of the donor tissue, and the minimally invasive microsurgical technique, it is especially the indication-dependent closemeshed follow-up which plays an important role in the long-term success of penetrating keratoplasty. In the follow-up process, the repeated emphatic sensitization of the patient to alarming subjective symptoms and the informed involvement of the ophthalmologist in private practice providing the follow- up treatment must be considered of crucial importance. “Treat them and street them” is certainly not the motto to follow!