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.