Acanthamoeba keratitis: clinical characteristics and management

Ophthalmology. 2006 Mar;113(3):412-6. doi: 10.1016/j.ophtha.2005.10.041. Epub 2006 Jan 20.


Objective: To review the clinical characteristics, treatment, and outcome of patients with Acanthamoeba keratitis (AK).

Design: Retrospective, noncomparative, interventional case series.

Participants: Twenty consecutive patients with AK were referred to the Beijing Tongren Hospital, Capital University of Medical Science, China.

Methods: Retrospective analysis of medical records from 20 consecutive patients with AK between December 1, 1997 and March 30, 2003. Risk factors, laboratory investigations, clinical manifestations, treatments, and outcomes were analyzed.

Main outcome measures: Best-corrected visual acuity (BCVA) at the end of follow-up.

Results: Of the 20 patients presented in this series, 12 patients were students and 6 were farmers. Risk factors included contact lens wear (12/20) and trauma (6/20). Corneal ulceration, diffuse stromal infiltration, and ring infiltration were the main clinical manifestations. The diagnosis of all patients was based on the laboratory investigation. Smear and culture positive specimens were 19 of 20 and 12 of 20, respectively. Images of cysts were demonstrated with confocal microscopy in 4 patients. Treatment was combined instillation of chlorhexidine (0.02%), neomycin (0.5%), metronidazole (0.4%), and/or lesion cauterization with chlorhexidine (1%), and corneal lesion debridement. The mean duration of therapy was 70 days (range, 18-150 days). Nineteen lesions healed with scar formation. The BCVA was better or equal to 20/100 in 7 eyes.

Conclusions: Early diagnosis of AK is the key challenge in clinical practice. The combined use of antiacanthamoeba agents, debridement, and cauterization may be a best choice of treatment for patients who are diagnosed early in the course of their disease.

MeSH terms

  • Acanthamoeba Keratitis / diagnosis*
  • Acanthamoeba Keratitis / drug therapy
  • Acanthamoeba Keratitis / pathology
  • Acanthamoeba Keratitis / surgery
  • Acanthamoeba Keratitis / therapy*
  • Adolescent
  • Adult
  • Anti-Infective Agents, Local / administration & dosage
  • Anti-Infective Agents, Local / therapeutic use
  • Antiprotozoal Agents / therapeutic use*
  • Cautery*
  • Child
  • Chlorhexidine / administration & dosage
  • Chlorhexidine / therapeutic use
  • Debridement*
  • Drug Combinations
  • Early Diagnosis
  • Female
  • Humans
  • Male
  • Metronidazole / administration & dosage
  • Metronidazole / therapeutic use
  • Middle Aged
  • Neomycin / administration & dosage
  • Neomycin / therapeutic use
  • Ophthalmic Solutions
  • Retrospective Studies
  • Risk Factors


  • Anti-Infective Agents, Local
  • Antiprotozoal Agents
  • Drug Combinations
  • Ophthalmic Solutions
  • Metronidazole
  • Neomycin
  • Chlorhexidine