– A local necrosis of corneal tissue that ultimately leads to scarring and reduced visual acuity.
Causes and Incidence
The most common cause is infection following trauma or contact lens overwear. Other causes include herpes simplex infection, chronic blepharitis, conjunctivitis, gonorrhea, trachoma, chemical burns, prolonged exposure to air in the absence of a blink reflex, and severe vitamin A or protein depletion resulting from malnutrition.
The cornea usually becomes infected or inflamed through an outside agent or chronic irritant, and a dull, grayish lesion forms and then necroses and suppurates, creating an ulcer. The ulcer may or may not infiltrate deeper layers of tissue. The deeper the penetration, the more severe the signs, symptoms, and complications. As the ulcer heals, it is replaced by fibrous tissue, which causes opaque scarring and reduced vision.
Pain, tearing, and photophobia are the most common manifestations. Bloodshot eyes and pus in the anterior chamber behind the cornea may be present in chronic cases.
Perforation of the cornea, with a prolapse of the iris and eventual destruction of the eye, is the major complication.
A fluorescein stain turns green and readily delineates the ulcerated area. A slitlamp examination allows inspection of the eye’s surface and the deeper layers of the cornea to determine the extent of ulceration. Cultures identify the infectious organism.
Repair of any laceration or removal of foreign object; removal of prolapsed tissue; corneal transplantation for severe scarring or perforation.
Topical anesthetics for pain; topical and systemic antibiotics, antifungals, and antivirals to treat infection; topical steroids to treat inflammation; mydriatics to dilate pupil with increased intraocular pressure; cycloplegics to restrict eye movement and reduce pain.
Warm compresses for lid swelling; irrigation to cleanse eye; bilateral pressure dressings to aid reepithelialization; dark glasses for photophobia.