Abstract
Purpose :
Acanthamoeba keratitis is a vision threatening disease. Topical treatment is often not successful and patients often need corneal transplantation for treatment. Herein we describe the history of eight patients with acanthamoeba keratitis resistant to topical treatment, who were successfully treated with phototherapeutic keratectomy (PTK) and mitomycin 0.02% application.
Methods :
Eight patients (eight eyes) with diagnosed acanthamoeba keratitis and unsuccessfully topical treatment for three months {Brolene and Polyhexamethylenbiguanid (PHMB)} underwent PTK (80 to 120 µm depth; 8 to 9 mm optical zone) after epithelium removal with topical mitomycin 0.02% application (90 seconds) between 2009 and 2018. Active acanthamoeba keratitis was diagnosed in all patients on the day of PTK by corneal scrape and culture or confocal microscopy (HRT, Heidelberg Engineering). Confocal microscopy showed the cysts at a depth of up to 240µm in the the mid stroma. Therapeutic contact lens was always applied until epithelial closure.Topical treatment with PHMB, topical lubrication and dexamethasone TID was continued for up to 6 weeks and then stopped. Postoperative follow up time was 6 months to 8 years.
Results :
Acanthamoeba cysts could be eradicated in all eight cases. Visual acuity increased in all but one two patients. One patient developed a dense cataract during the treatment and another patient underwent penetrating corneal transplantation due neurotrophic corneal ulcer and severe pain. Histology of the corneal tissue did not show any acanthamoeba cysts in the corneal tissue. DCVA was 1.0 to 0.1 logMAR in all patients six months after PTK. Epithelial closure was seven to 20 days post-operatively. None of the patients developed a recurrence during the entire follow up period of up to 8 years.
Conclusions :
The combination of 100µm PTK with mitomycin 0.02% for 90 seconds can be a successfull approach for the treatment of acanthamoeba cysts in patients, who are resistant to topical treatment. This protocol seems also to be successful in corneas with cysts at the depth of up to 240µm. However, confocal microscopy should be performed before laser application to measure the depth of the cysts and to control the post-operative success of the treatment.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.