A 52 y.o. woman with a hx of anxiety had been rubbing her eye because it was itching
She complains now of decreased vision
What is wrong?
Our patient developed a corneal ulcer from trauma. She continued to irritate it and developed stromal inflammation; the whitish material around the ulcer. Eventually, the globe perforated and the small dark circle inferiorly represents the iris herniating outward. One million ED visits in the US each year are for keratitis.
Keratitis is inflammation of the cornea. The stroma is the thickest layer of the cornea; seen here in blue.
CAUSES OF KERATITIS
Trauma- often is found in contact lens wearers any break in the corneal can also predispose to infection
Infection-is the most common cause of corneal ulcers. .12% of all corneal transplants are performed for ulcers caused by infection .
Bacterial infection- is most commonly Staph but Pseudomonas is often present in contact lens wearers
Viral infection= HSV is the most common cause of viral keratitis.
Fungal infection- is more common in agricultural workers.
Protozoal infection- Acanthamoeba causes keratitis and can be found in hot springs in Arkansas, Lake Mead and hot tubs.
acanthamoeba can cause a paracentral ring in the stroma and may lead to blindness.
Autoimmune diseases also cause keratitis- Rheumatoid arthritis and Wegener’s are known to cause
a peripheral crescent shaped keratitis as shown below.
Our patient underwent surgery to repair the cornea. Her vision remained cloudy post-op.
Pepose J, Wilhelmus K. Divergent approaches to the management of corneal ulcers. Am J Ophthal 1992 Nov 15:114(5):650-652.
Cao Y, Zhang W, Wu J, et al. Peripheral ulcerative keratitis assoiated with autoimmune disease pathogenesis and treatment. J of Ophthal 2017, 2017 7298026.
Cope J, Collier S, Srinivasan K, et al. Contact lens related corneal infections in the US. 2005-2015 MMWR2016 Aug 19,63(32):817-20.
Hot springs in Arkansas contain protozoans which can cause keratitis. Naegleria fowleri , another protozoan, can cause a fatal granulomatous encephalitis. Beware!