PENETRATING KERATOPLASTY AND SUPPORTIVE C RYOTHERAPY IN ADVANCED ACANTHAMOEBA-KERATITIS

Background: Since the mid-1980s acanthamoeba keratitis has been diagno sed with increasing frequency, especially in contact lens wearers. The assignment to specialized centers is often delayed many months and th ere is hardly any chance of controlling the disease by conservative tr eatment alone. In these cases, penetrating keratoplasty offers the onl y chance for rehabilitation. The therapeutic role of penetrating kerat oplasty and supportive intraoperative cryotherapy is demonstrated by t he courses of six patients with unilateral acanthamoeba keratitis. Pat ients and methods: The data of six patients aged 41.2 (22-63) years wi th medically uncontrollable acanthamoeba keratitis were evaluated retr ospectively. The diagnosis was confirmed histologically in all cases. All patients were contact lens wearers. They underwent a total of ten keratoplasties between November 1986 and January 1995. The donors were 44.8 (23 - 58) years of age. The transplant diameters varied between 7.7 and 9.5 mm. The margins of the host cornea were intraoperatively f rozen by a cryoprobe in three patients with a far advanced stage of co rneolimbal parasitic infiltration. Results: During a follow-up period of +/- 10.2 (1 - 22) months, five of six eyes were rehabilitated with visual acuities between 0.4 and 1.0. One eye went blind after the four th keratoplasty because of uncontrollable secondary glaucoma. After th ree keratoplasties with simultaneous application of cryocoagulation be cause of an especially high risk of persisting acanthamoeba infection, all corneae remained clear and free of recurrences. Conclusions:ln ad vanced acanthamoeba keratitis which has not responded to conservative treatment, penetrating keratoplasty not only provides elimination of t he pathogen, but also good functional results. In far advanced stages, the intraoperative application of cryocoagulation for parasite elimin ation in the host cornea seems to be a very effective measure against local recurrences of the infection.