CENTRAL CORNEOLIMBAL TRANSPLANTATION UNDER SYSTEMIC CYCLOSPORINE-A COVER FOR SEVERE LIMBAL STEM-CELL INSUFFICIENCY

Background: Severe stem cell deficiencies uniformly lead to superficia l conjunctivalization of corneal grafts with subsequent functional fai lure. We sought better long-term results by transplanting central corn eolimbal grafts and simultaneously protecting the graft and its stem c ells from immunological destruction by means of systemic administratio n of ciclosporin A. Patients and methods: In an ongoing pilot study, u p to April 1995 20 eyes with stem cell dysfunctions of various etiolog y (e.g. chemical burn, ocular pseudopemphigoid, congenital aniridia) r eceived eccentrically trephined fresh corneal grafts of 7.7-10.0 mm di ameter. About one third of the circumference of the grafts contained l imbal area. The mean age of the patients was 46.2 years (range 9-84 ye ars). All patients received systemic ciclosporin A for at least 12 mon ths. At present, the mean follow-up period is 9.6 months (mean 1-20.6 months). Results: Fourteen of 20 grafts (70%) have remained clear so f ar. Reasons for six graft failures were surface disorders in four eyes , immune reactions in one eye and surface disorders in combination wit h immune reactions in another eye. Ten of 20 grafts (50%) experienced severe surface disorders. In six eyes surface disorders were coinciden t with endothelial immune reactions, in four eyes they were not. In fo ur of 20 grafts (20%) conjunctivalization was observed in front of the transplanted limbal area; in seven of 20 grafts (35%) conjunctivaliza tion occurred only distant from the transplanted limbal stem cells. Co nclusions: Our method of central corneolimbal transplantation with sim ultaneous protection of the transplanted stem cell population from imm unological destruction by means of systemic ciclosporin A has been suc cessful for 14 eyes with severe stem cell deficiencies up to 20.6 mont hs postoperatively. This new treatment principle promises - for the fi rst time - long-term rehabilitation for a majority of eyes with severe limbal stem cell deficiencies.