Corneal Ulcer – An abscess on the surface of the cornea.
A superficial ulcer involves only the outermost layer, or epithelium of the cornea, but in more serious cases the subsequent layer, or stroma, may also be involved. Immediate treatment should be sought if a corneal ulcer is suspected.
If treated early, superficial ulcers usually heal in about 1 week, but if allowed to penetrate the deeper layers of the cornea, scarring of the cornea may occur, compromising vision.
Treatment includes the application of fortified antibiotics, antifungal, or antiviral eye drops.
Once the infection clears, a steroid drop may be used to reduce swelling and the possibility of scar formation.
In more extreme cases, a corneal transplant may be needed.
Pain, redness, tearing, and blurred vision are common signs and symptoms of corneal ulcers. In some cases, a white spot, with a cotton-like appearance, is also visible on the cornea.
The majority of the corneal ulcers are caused by infections due to bacteria or viruses, or are fungal in nature.
Protozoal infection by acanthamoeba can also result in corneal ulceration.
- Bacterial ulcers – Occur when bacteria are able to enter the cornea through an area that has become compromised by infection or injury. Many bacterial ulcers are linked to improper contact lens wear, cleaning, and handling.
- Viral ulcers – Can occur when a virus, such as herpes simplex (which causes cold sores), herpes zoster, or the varicella virus (which causes chicken pox and shingles) enters the body, causes infection, and then goes into a dormant state in the center of the body. Upon reactivation, the virus can travel down the nerve and into the eye. Once in the eye, a viral infection will occur, the cornea can become compromised, and corneal ulcer formation can occur.
- Fungal ulcers – Occur when a fungus is able to enter the cornea through an area that has become compromised by infection or injury. This usually occurs when fungi, which are commonly present on plant material and soil, enter the eye.
- Acanthamoeba keratitis – Occurs when the amoeba enters the cornea through an area that has become compromised by infection or injury. Acanthamoeba live in soil and water. Contact lens wearers are more susceptible to this type of infection, especially if they do not sterilize their contact lenses properly, or wear them while in swimming pools or hot tubs.
- Neurotrophic ulcers – Also called exposure keratopathy, can occur in people with severe dry eye syndrome or conditions of the eyelid, where the eyelid does not close completely. Sufficient tears on the eye provide a layer of germ protection, thus dry eye sufferers lose this innate protection. In addition, severe dry eye or exposure can damage the surface of the cornea, leaving it prone to ulcer formation.
- Immunological ulcers – Occur in people diagnosed with specific autoimmune or connective tissue disorders such as rheumatoid arthritis, Sjogren’s syndrome, lupus, or scleroderma.