Acanthamoeba Keratitis in Egypt: Characteristics and Treatment Outcomes

PURPOSE: To study the predisposing factors, clinical manifestations, and treatment outcome of patients with Acanthamoeba keratitis (AK) at Tanta University’s Ophthalmology Hospital in Tanta, Egypt. METHODS: A retrospective study of 42 patients (44 eyes) with Acanthamoeba keratitis who had medical records available for review over 4 years. RESULTS: Forty-four eyes of 42 patients were treated for AK over the study period. In 29 eyes (65.8%), AK was related to contact lens wear. Severe ocular pain was the main presenting symptom in 38 eyes (86.3%). The most common ocular signs were radial perineural corneal infiltrates (65.9%), pseudo-dendrites (43.2%), ring infiltrates (45.5%), and diffuse stromal infiltration (59%). Acanthamoeba was detected by culture, smear, and in-vivo confocal microscopy (IVCM) in 25 eyes (56.8%), while in 19 eyes (43.2%) the diagnosis was based solely on the clinical findings. IVCM was effective in detection of Acanthamoeba in cases with early presentation, while culture was more sensitive in late presentation with corneal melting. The mean duration of treatment was 73.3 ± 23.7 days. Surgical intervention in the form of tectonic grafts or amniotic membrane transplant was required in five cases (11.3%) due to progressive corneal thinning and perforation. Seventeen patients (38.6%) had 0.2 or better final best-corrected visual acuity after treatment. CONCLUSION: The diagnosis of AK remains a major challenge for most ophthalmologists. Contact lens abuse is the major risk factor. Early diagnosis and appropriate treatment of AK with biocidal agents can improve the final outcome and help avoid surgical intervention. IVCM is an excellent tool for early diagnosis of AK.