Successful treatment of Pseudallescheria boydii keratitis with topical natamycin as monotherapy

To report a case of Pseudallescheria boydii keratitis successfully treated with topical natamycin as monotherapy.

Interventional case report describing the clinical presentation, histopathologic findings, course, and treatment of a patient with P. boydii keratitis.

A 50-year-old male electrician with a 4-day history of right eye pain and blurring of vision was referred. There was history of right eye injury while hammering and examining a hole in the ceiling. Examination showed a corneal abscess with overlying epithelial defect measuring 2 mm in diameter. Histopathologic investigation revealed septate hyaline cylindrical hyphae with acute angle branching and formation of oval to pyriform conidia truncated at the base, compatible with P. boydii. The patient was treated with topical natamycin 5%, which eradicated the infection, resulting in a final best-corrected visual acuity of 6/7.5.

The fungus P. boydii can cause keratitis. The success rate for treatment was generally thought to be poor. Early detection and treatment is important in improving the outcome. This is believed to be the first reported case of P. boydii keratitis successfully treated with topical natamycin as monotherapy.