Corticosteroid use before Acanthamoeba keratitis diagnosis increases risk of poor visual outcome
Use of topical corticosteroid before the diagnosis of Acanthamoeba keratitis was highly predictive of worse visual outcomes, according to study findings.
The retrospective cohort study included 196 eyes of 196 patients diagnosed with Acanthamoeba keratitis (AK) between January 1991 and April 2012. Patients were separated into two groups: the exposed cohort, which included patients treated with prior corticosteroids, and the unexposed cohort, which included patients treated without prior corticosteroids. The majority of patients were treated with a dual therapy of biguanide (polyhexanide 0.02, 0.06% or chlorhexidine 0.02, 0.2%) and diamidine (propamidine 0.1% or hexamidine 0.1%).
The study’s primary outcome was suboptimal visual outcome, which the researchers defined as best-available visual acuity of 20/80 or less, corneal perforation or need for keratoplasty.
Ninety-four eyes were diagnosed with AK on microbiological culture, 27 eyes on historical examination, 38 eyes on confocal microscopy and 37 eyes on basis of typical clinical course and response to treatment, according to the researchers.
In a multivariate analysis of the 174 eyes with final VA and corticosteroid use data available, the researchers found corticosteroid use before diagnosis of AK was associated with suboptimal visual outcomes.
Additionally, patients 60 years or older and those with disease stage three — defined as having presence of a corneal ring infiltrate and either presence of one or more corneal epithelial defect, perineural infiltrate or stromal infiltrate — had increased risks for poorer visual outcomes.
Disclosure: The authors have no relevant financial disclosures.