Acanthamoeba keratitis: 10-Year study at a tertiary eye care center in Hong Kong

•Contact lens wear remains the most commonly associated risk factor for Acanthamoeba keratitis in our study.•Microbiological detection of Acanthamoeba can be supplemented by confocal microscopic examination in cases with high suspicion.•Timely diagnosis and treatment of Acanthamoeba keratitis can prevent serious ocular morbidity.

PurposeTo review clinical presentation, investigation results and treatment outcomes of patients with Acanthamoeba keratitis (AK) at a tertiary eye care center in Hong Kong.MethodsA retrospective case review was performed for cases of Acanthamoeba keratitis diagnosed at the Prince of Wales Hospital, Hong Kong over a 10-year period.ResultsFifteen eyes of 13 patients were treated for AK over the study period. 12 out of 13 patients (92.3%) were contact lens wearers. All patients presented with blurred vision and pain, while 9 patients (69.2%) presented with redness of the affected eye. The most common ocular sign was diffuse corneal haze or ground glass appearance of the cornea (69.2%) followed by anterior chamber inflammation (53.8%), ring infiltrate (38.4%), epithelial defect (38.4%), perineural infiltrates (30.7%) and satellite lesions (15.3%). Acanthamoeba was detected on corneal scrapings in 4 eyes and on confocal microscopy in 4 eyes. The mean duration of treatment was 140 ± 50.8 days. Surgical intervention was required in two cases due to uncontrolled eye infection and progressive corneal thinning. All patients had improvement in visual acuity after treatment.ConclusionsPatients with AK exhibited a wide spectrum of clinical characteristics. Improper care and usage of contact lenses is a major risk factor for Acanthamoeba keratitis. Diagnosis of AK remained a challenge. Timely diagnosis and appropriate treatment with amoebicidal drugs can improve the outcomes of Acanthamoeba keratitis.