Szemészet, 1975 (112. évfolyam, 1-3. szám)
1975 / 3. szám
b) The degree of vascularization has a marked effect on the incidence and reversibility of rejection. c) The sharing of HL—A antigens affects mainly the reversibility of rejections. d) For cases at high risk of rejection, because of marked vascularization, the sharing of even only two antigens between donor and recipient significantly improves the prognosis. Corticosteroid therapy is by far the most important weapon in treating the allograft reaction and opacification. We have no indications whether the barrier of healthy corneal tissue-surrounding the graft and conferring immunological privilage — is more important on the afferent or on the efferent side of the immunological reflex arcs. Whichever of these routes is operative, topical corticosteroid therapy is expected to impede both the afferent and efferent flows by a) its vasoconstrictive effects b) its lympholytic action, operating on lympocytes arriving at the graft by whatever route and also c) acting on the local lymphoid tissue in diseased eyes. This tissue may constitute a peripherally sited central section of the immune response (Barrie R. Jones). The effectiveness of the corticosteroid therapy in preventing and treating the allograft reaction is conditioned by a) the time at which therapy is begun b) the time of onset of the responce post-operatively and c) the condition of the barrier of the recipient cornea (vascularization, width, etc). The best response to therapy is expected if: a) treatment begins at the earliest possible time after the clinical manifestation of allograft reaction b) the onset of the response comes soon (a few weeks) after surgery; in cases of late onset the results are definitely better c) neo-vascularization is minimal or absent and d) the size of the graft is 8 mm or less. (Maumenee). The steroid therapy is useful both in systemic and topical application. We think that preventive treatment is nessesary as a rutine measure against graft rejection, in only well selected cases. For example in vascularized corneas, one week before surgery, prednizole 2 1/2% ointment is given (1-2 t. daily) and according to the case, topical steroids are used till the eye becomes quiet — several weeks after surgery. The possibility of steroid glaucoma must be born in mind, when treating these patients. The surgeon must be alert in recognizing, as early as possible, the allograft reaction of the grafted cornea. The exact dosage and time of therapy varies from case to case. This treatment is practically the only weapon in our hands hence the need to be applied early and efficiently. The surgeon must be aware of the advantages of topical, subconjuctival and systemic administration and to adjust the treatment to every individual case. From the important experimental and clinical reasearch of the last decade on the extremely complex field of corneal transplantation, some practical rules have emerged concerning prevention and treatment of corneal graft rejection syndrome. These rules being applicable to every case of keratoplasty, are especially valid to the penetrating grafts. a) The preparation of the recipient eye for surgery, is a fundamental concern of the surgeon. (Disorders, like poor lacrimal secretion, conjuctival scars, neovascularization of the cornea, glaucoma, must be treated before surgery.) b) Of great importance is to achieve donor eyes in excellent condition— according to the generally accepted criteria; care must be taken to avoid any mechanical or other insult to the donor tissue till the time of surgery (enucleation, transportation, preservation). c) The surgical manipulation of the donor as well as the recipient cornea 176 T
