R 37Perspectives of penetrating keratoplasty
T. Reinhard, R. Sundmacher
Long-term clear graft survival is influenced by a variety of factors. Here, we discuss (1) possibilities to avoid immune reactions, (2) perspectives to minimize idiopathic endothelial cell loss and (3) measures to detect intraocular pressure decompensation in time.
(1) Topical steroids or systemic Cyclosporin A are well-known medications for the prophylaxis of immune reactions after penetrating keratoplasty. New options, tested in animal keratoplasty models, but not yet in patients, are topical Fk 506 or systemic rapamycin. In severe high-risk situations, however, these measures alone are often not sufficient. In the future, the use of optimally HLA-matched grafts, oral induction of antigen tolerance and moleculargenetic measures may contribute to improve graft prognosis.
(2) Idiopathic endothelial cell loss is defined as a continuing postoperative decrease in endothelial cell density of penetrating grafts. A subclinical immune reaction is supposed to be the cause of this phenomenon which leads to graft failure in the long run in most keratoplasty patients. There are hints that in patients with optimally HLA-matched grafts idiopathic endothelial cell loss is less severe than in patients with a poor HLA-match. If this impression is confirmed in larger studies the use of optimally HLA-matched grafts must be recommended for all penetrating keratoplasties.
(3) Postoperative intraocular pressure decompensation is responsible for a statistically significant impairment of graft prognosis. Recently, an electronic tool was introduced to obtain reliable intraocular pressure values after penetrating keratoplasty for the first time. It can expected that electronic intraocular pressure measurement as the basis for therapeutic measures will contribute considerably to an improvement of graft prognosis in glaucoma eyes.
Eye Hospital, Heinrich-Heine-University, Moorenstr. 5, D-40225 Düsseldorf