Corneal erosion refers to a chronically recurring eye problem in which the outer layer of the cornea is damaged. Most cases of corneal erosion are triggered by single or repeated direct injuries, but an underlying medical condition can also weaken the cornea. Symptoms may include blurry vision, excessive tears, redness, and pain. Treatment depends on the severity of tissue damage, but most people are able to find relief from symptoms with medicated eye drops. Surgery is needed in serious cases to limit the risk of permanent vision loss.
The cornea is covered with a layer of epithelial cells that protect underlying structures. If the epithelial layer is scratched or punctured, a painful corneal abrasion can result. Recurring erosion happens when abrasions seriously damage the epithelium, separating it from the next layer of tissue called the Bowman membrane. With the Bowman membrane exposed, the eye is highly susceptible to future injuries.
A fingernail scratch, a poke from a tree branch, or a foreign particle that gets lodged in the eye can all trigger corneal erosion. Trauma can also result from wearing contact lenses or exposure to toxic chemicals. People who have certain autoimmune disorders, diabetes, or corneal dystrophy may experience erosion in absence of a direct injury.
A person who experiences a traumatic eye injury is likely to suffer from immediate pain and tearing. Blurry or spotty vision may occur and persist for several days. Symptoms tend to relieve themselves within a week, but underlying corneal erosion can still be active without causing physical pain. In fact, most people who have recurring corneal erosion do not notice problems until they experience future injuries. When symptoms are present, they may include pain, blurriness, and an inability to focus.
An eye doctor should be consulted following a severe injury or recurring vision problems. The specialist can examine the eye with a type of microscope called a slit lamp to check for epithelial punctures and erosion. He or she usually reviews a patient's medical history and symptoms to confirm a diagnosis and possibly identify an underlying cause. After a careful examination, the doctor can determine the best way to treat an erosion.
When trauma is responsible for relatively minor symptoms, a patient is usually given topical antibiotics and fitted with a patch to protect the eye. After two to three days, the doctor can re-examine the cornea to determine if recurring erosion is likely. The patient may need to apply daily eye drops and change contact lenses to reduce the risk of future problems. Surgery may be necessary to remove part or all of the epithelium and cover the Bowman membrane with an artificial lens or chemical substance. After surgery, a patient can usually recover vision within a few weeks.