Ultraviolet-A Light and Riboflavin Therapy for Acanthamoeba Keratitis: A Case Report

Abstract

Purpose: To report ultraviolet-A (UV-A) light treatment in a patient with Acanthamoeba keratitis (AK). Methods: Interventional case report. A standard protocol for ultraviolet corneal therapy, with a power emission of 3 mW/cm² and a wavelength of 370 nm, was used. The protocol included an 8-nm bandwidth at a 54-mm distance measured with a collimation system of diodes as well as a protective shield of riboflavin in a case of documented AK. Results: A 54-year-old female patient with AK, showing no therapeutic response to a wide variety of topical antimicrobial agents and with a visual acuity of 20/400, was treated with UV-A therapy. The patient displayed a favourable response in the first 24 h after treatment, with improvement of symptoms, visual acuity (to 20/200) and biomicroscopy cornea with haze degree I. By the third week post-treatment, the patient was symptom-free. Her visual acuity was 20/30, and the affected cornea was clear. Five months after treatment, there had been no recurrence, and her vision was 20/20. Conclusions: Treatment with UV-A light was an effective therapy in this case of AK.

Pathogenesis of microbial keratitis

“…Recently, photorefractive surgery seems to be a very promising modality and have been used in four cases of early stage Acanthamoeba keratitis, where the patients developed large corneal abscesses in the upper third thickness of stroma [85]. Another relatively new approach is collagen cross-linking which has shown promising results in clinically [48,92,126]. It is presumed that collagen probably prevents further tissue damage and prevents reproduction of amoebae and hence the patients showed rapid reduction in ocular symptoms and ulcer size.…”

Advances in the Diagnosis and Treatment of Acanthamoeba Keratitis

“…Whilst in vitro studies by Kashiwabuchi et al [43] and del Buey et al [44] have shown no amoebacidal effect of riboflavin combined with UVA exposure, clinical case reports have shown a much more promising picture. Garduño-Vieyra et al [45] administered collagen cross-linking to a patient in Mexico in place of topical medical therapies, which were not commercially available. A significant improvement was observed after 24 hours, with symptoms resolving within three months, and a 20/20 vision was obtained after five months.…”

Treatment of Acanthamoeba Keratitis by Corneal Cross-linking

“…There are some anecdotal case reports of successful treatment of Acanthamoeba keratitis by corneal CXL. 24,25 In the present study, corneal CXL treatment with riboflavin was evaluated both clinically and microbiologically. The CXL treatment of Acanthamoeba keratitis was not effective in decreasing the intensity and severity of infection.…”