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Risk factors, demographics and clinical profile of Acanthamoeba keratitis in Melbourne: an 18-year retrospective study
  1. Matthew Hao Lee1,
  2. Robin Geoffrey Abell2,
  3. Biswadev Mitra3,
  4. Merv Ferdinands4,
  5. Rasik B Vajpayee2
  1. 1 Department of Ophthalmology, Royal Melbourne Hospital, Melbourne, Victoria, Australia
  2. 2 Corneal Unit, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia
  3. 3 Department of Epidemiology and Preventative Medicine, Monash University, Melbourne, Victoria, Australia
  4. 4 Department of Ophthalmology, University Hospital Geelong, Geelong, Victoria, Australia
  1. Correspondence to Dr Matthew Hao Lee, Royal Melbourne Hospital, 300 Grattan St, Parkville VIC 3050, Australia; matthewhaolee{at}


Purpose To assess incidence, risk factors, presentation and final visual outcome of patients with Acanthamoebakeratitis (AK) treated at the Royal Victorian Eye and Ear Hospital (RVEEH), Melbourne, Australia, over an 18-year period.

Methods A retrospective review of all cases of AK managed at RVEEH between January 1998 and May 2016 was performed. Data collected included age, gender, affected eye, signs and symptoms, time between symptoms and diagnosis, risk factors, presenting and final visual acuity (VA), investigations, medical treatment, surgical interventions and length of follow-up.

Results A total of 36 eyes affected by AK in 34 patients were identified. There were 26 cases diagnosed early (<30 days) and 10 were diagnosed late (≥30 days). There were 31 (86.1%) cases associated with contact lens (CL). Signs associated with early AK included epithelial infiltrates, while signs of late AK included uveitis, ring infiltrate, endothelial plaque and corneal thinning (p<0.05). Surgical treatment was required in seven cases (19.4%). There were 29 (80.6%) cases that reported improved VA. Median best corrected final VA was worse in patients with late diagnosis (logarithm of minimal angle of resolution (logMAR) 0.5, IQR: 0.2–0.8), compared with patients with early diagnosis (logMAR 0.0, IQR: 0.0–0.3; p=0.01). Late diagnosis was associated with a prolonged disease period.

Conclusion AK was an uncommon cause of severe keratitis and was associated commonly with CL. Patients with late diagnosis had worse presenting and final VAs as well as a prolonged disease period, indicating need for early recognition and management.

  • cornea
  • epidemiology
  • infection
  • microbiology

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  • Contributors All authors certify that they have participated sufficiently in the work to take public responsibility for the content, including participation in the concept, design, data collection and analysis, writing and revision of the manuscript.

  • Competing interests None declared.

  • Ethics approval Royal Victorian Eye and Ear Hospital Human Research Ethics Committee.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data sharing statement No further data relating to this study are available.

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