The cornea is the clear covering on the front of the eye. The cornea functions to protect the eye, as well as to help focus light onto the back of the eye.
Diagram showing the location of the cornea compared to the other structures in the eye. The cornea is the clear window on the front of the eye that protects the eye and helps focus light.
What is an ulcer?
An ulcer (“open sore”) is a break in the normal epithelium of the body. The epithelium is a layer of cells that lines surfaces of the body. Ulcers commonly occur on the skin, the digestive tract (e.g. stomach, intestines) and eyes. Most often, ulcers are associated with infection or inflammation.
What is a corneal ulcer?
A corneal ulcer (“ulcerative keratitis”) is a disruption of the epithelium (outer covering) of the cornea. Corneal ulcers are relatively common, and are usually due to infection. Corneal ulcers can be very painful, and are sometimes an emergency.
What causes a corneal ulcer?
Most often, corneal ulcers are due to infection. Infection can be from:
• Viruses: herpes simplex virus commonly causes a corneal ulcer • Bacteria: most bacterial corneal ulcers are due to an underlying problem in the cornea • Fungi: fungal corneal ulcers are rare, but can be very serious • Parasites
Sometimes, a corneal ulcer may occur without an infection. Non-infectious causes include:
• Contact lenses: especially if they are improperly cleaned • Injury to the eye: includes trauma or chemicals • Certain eye drops (especially steroids) • Certain diseases • Vitamin deficiencies (especially vitamin A and vitamin C)
What are symptoms of a corneal ulcer?
Symptoms of a corneal ulcer can include:
• Red eye • Eye pain • Tearing • Discharge • Foreign body sensation • Vision problems (e.g. blurred vision, light sensitivity) • White spots on the cornea
Diagram showing the appearance of a typical corneal ulcer. This ulcer should be seen by an ophthalmologist right away.
How is a corneal ulcer diagnosed?
The diagnosis of a corneal ulcer is made through a history and eye exam. The eye exam will include visualization of the cornea and surrounding structures with a slit-lamp. The doctor may use fluorescent dye to help view the surface of the cornea.
If the ulcer is due to an infection, the doctor may send a swab for a culture to determine the exact cause. This helps guide treatment.
How is a corneal ulcer treated?
The treatment of a corneal ulcer depends on the cause and the severity. For infectious ulcers, eye drops such as antibiotics (for bacteria), antivirals (for viruses) or antifungals (for fungi) may be given.
Since many corneal ulcers are very painful, eye drops to decrease the pain are frequently given as well.
Sometimes, a corneal ulcer may be so severe that the inner layers of the cornea are damaged. In these cases, a corneal transplant may be considered. To read more about a corneal transplant, click here.
If the ulcer is due to an underlying cause, such as contact lenses or vitamin deficiencies, the underlying cause should be treated.
What are the complications of a corneal ulcer?
It is important that corneal ulcers be treated promptly. Certain infectious causes can lead to permanent damage quickly.
If left untreated, there may be corneal scarring, corneal perforation or glaucoma.
