Pythium insidiosum Keratitis in Contact Lens Wear: A Case Report

Purpose: The purpose of this study was to report a case of contact lens-related Pythium insidiosum corneal ulcer. Methods: The authors conducted an interventional case report. We report the clinical presentations, histopathologic findings, and treatments of a patient with P insidiosum keratitis associated with contact lens wear. Results: A 22-year-old Thai woman presented to our clinic with a nonresponsive, progressive corneal ulcer of the left eye. Slit lamp examination showed a large central ulcer measuring 5.4 x 5.2 mm with underlying dense stromal infiltrates surrounded by subepithelial and superficial stromal opacity in a reticular pattern along with radial perineural-like infiltrates. Histopathologic examination revealed broad, branched, thin-walled nonparallel hyaline hyphae with rare septates consistent with P insidiosum. The corneal culture confirmed the diagnosis. The infection recurred after multiple therapeutic penetrating keratoplasties. Enucleation was eventually performed to eradicate the infection. No definite report of contact lens-related P insidiosum keratitis existed in the literature. Conclusion: Pythium keratitis may present with central ulcer and radial keratoneuritis similar to acanthamoeba keratitis. Contact lens wear can be a risk factor for this infection. Increasing awareness, early diagnosis, and intervention may improve the prognosis.