Delayed diagnoses of Acanthamoeba keratitis at a tertiary care medical centre

Yesha S. Shah, Inna G. Stroh, Sidra Zafar, Nancy Zhang, Manjari Sriparna, Nakul Shekhawat, Zara Ghos, Divya Srikumaran, Fasika A. Woreta

Research output: Contribution to journalArticlepeer-review


Purpose: To determine the prevalence and reasons for delays in diagnosis in patients with Acanthamoeba keratitis (AK) presenting to Wilmer Eye Institute, Baltimore, Maryland. Methods: This retrospective study analysed all patients with culture-positive AK seen between 2012 and 2019 at a tertiary referral centre. Patient demographic information, clinical history, risk factors, symptom duration, referral patterns, slit lamp examination findings, visual acuity and need for surgery were collected. Results: The study included 45 eyes of 43 patients. On average, patients were symptomatic for 52.6 days before culture collection. Thirty-one percent of patients were diagnosed within 28 days of symptom onset while 69% were diagnosed after 28 days. Before presentation to a tertiary care centre, 69% of patients were evaluated by an ophthalmologist outside of this institution and 27% were evaluated by a provider other than an ophthalmologist. AK was most commonly misdiagnosed as herpetic keratitis, occurring in 38% of patients. The strongest risk factor for AK was contact lens use. Only 11% of patients presented with the classic ring infiltrate and 82% had pain. Patients with an early versus late diagnosis had a mean Snellen visual acuity (VA) of 20/224 versus 20/296 at presentation (p = 0.33) and a mean Snellen VA of 20/91 versus 20/240 at final visit (p = 0.07). 11% of patients required a therapeutic penetrating keratoplasty. Conclusion: Delayed diagnosis of AK in our cohort occurred due to a misdiagnosis as herpetic keratitis, non-specific clinical signs including the lack of pain in a number of patients, and a delay in referral to a tertiary care centre. Any contact lens wearer with an atypical keratitis should be referred promptly for Acanthamoeba cultures.

Original languageEnglish (US)
Pages (from-to)916-921
Number of pages6
JournalActa Ophthalmologica
Issue number8
StatePublished - Dec 2021


  • Acanthamoeba keratitis
  • corneal cultures
  • herpetic keratitis
  • misdiagnosis

ASJC Scopus subject areas

  • Ophthalmology


Dive into the research topics of 'Delayed diagnoses of Acanthamoeba keratitis at a tertiary care medical centre'. Together they form a unique fingerprint.

Cite this