Objective: To describe a series of patients with proved herpes simplex virus keratitis (herpetic keratitis) who also had documented Acanthamoeba keratitis.
Methods: Herpetic keratitis was documented with viral cultures, immunologic stains, or histopathologic examination for multinucleated giant cells in the corneal epithelium. Acanthamoeba organisms were identified using confocal microscopy and epithelial biopsy with hematoxylin-eosin staining. Biopsy of the stroma and epithelium was used to identify Acanthamoeba organisms in 1 case.
Results: Cultures for herpes simplex virus were positive in 6 of the 9 cases. Immunologic stains were positive in an additional 2 cases, and in 1 case multinucleated giant cells were present in the epithelium consistent with the diagnosis of herpes simplex virus keratitis. Tandem scanning confocal microscopic findings were positive for Acanthamoeba in 8 of the 9 cases, and all of them demonstrated Acanthamoeba organisms in epithelial scrape biopsy specimens. In 1 case, which was not evaluated with confocal microscopy, Acanthamoeba was detected using a stromal and epithelial biopsy. Two of the 9 patients had a history of contact lens use.
Conclusion: Acanthamoeba keratitis may be present as a secondary or opportunistic infection in patients with herpetic keratitis.