Four cases of Acanthamoeba keratitis treated with phototherapeutic keratectomy.

PURPOSE: To report 4 cases of Acanthamoeba keratitis treated with excimer laser phototherapeutic keratectomy (PTK) and to discuss the clinical efficacy of this procedure. METHODS: Four cases with early stage Acanthamoeba keratitis resistant to medical amoebic therapy for at least 1 week and with an enlarged abscess underwent PTK. RESULTS: After PTK, the infected corneal lesions were removed and the clinical symptoms rapidly resolved in all cases. Another 40-μm ablation was required as a result of the 1-week delay in performing PTK. There was no recurrence during the postoperative period. CONCLUSION: When lesions are limited to about one third of the superficial corneal stromal layer, PTK could be the most beneficial option for treating Acanthamoeba keratitis, resistant to medical amoebic therapy using chlorhexidine or polyhexamethylene biguanide, because of direct removal of resistant amoebic cysts and better visual recovery without irregular astigmatism.