A fungal corneal ulcer, or fungal keratitis, is an infection of the corneal stroma that can cause rapid visual loss and pain. Infectious corneal ulcers need to be treated as soon as possible to preserve vision. If left untreated, a fungal infection can lead to perforation of the cornea, loss of vision, and even loss of the eye.

Risk factors that can predispose to fungal keratitis include contact lens wear, eye trauma with vegetative matter, previous ocular surgery, topical steroid use, and immunosuppression.

Patients with a fungal corneal ulcer will complain of eye pain, light sensitivity, red eyes, and possibly reduced vision. The rapidity of the onset and progression of symptoms is typically slower than what is seen in bacterial keratitis. Fungal keratitis is much less common than bacterial keratitis, and the diagnosis is often made once traditional antibacterial medications fail to successfully treat an infection.

Yeast-like fungal species, such as Candida, are more common in fungal keratitis in the northern United States, while filamentous organisms, such as Fusarium, are more common in the southern United States.