Corneal abrasion

If the brain detects something harmful coming toward the eyes, there are several safety measures that kick in automatically. First, the eyelid begins to close. Second, the eye begins to roll upward to avoid impact. Third, the arms and head will assume a defensive posture to avoid injury to the eyes. Despite this amazing defense system, many things can damage the eye and cornea. Corneal pain due to disease or injury is severe due to the presence of bare nerve endings. Our brain uses pain to tell us something is not right.

Causes & risk factors

From a flying toy to a piece of paper, there are multiple causes for corneal abrasions. They can happen at any age and under many circumstances from playing sports to working on hobbies or yardwork where sharp objects are handled. Unfortunately, many of them are self-inflicted. Grazing the cornea with our fingernails, mascara brushes, tree branches, and other common items can cause a break in the outermost layer of the cornea called the epithelium. There are five layers to the cornea, with the outermost layer being the most susceptible to damage. Deeper layers of the cornea can be affected if the impact is strong enough to penetrate. Contact lenses can also cause abrasion if the lens has a rough or torn edge. If there is a foreign object lodged between the cornea and the contact lens, the object can abrade the cornea. Foreign objects can also become lodged in the inner upper eyelid where it can damage the cornea at every blink.

Symptoms

In most cases, the person will immediately know something is not right. There can be a range of pain from mild discomfort to intense stabbing like pain following the injury. Some diseases that damage the cornea may start out as mild pain and progress. Blurred vision and light sensitivity can also be present. The injured eye may also water uncontrollably.

Diagnosis

Diagnosis should be made by a doctor of optometry. Emergency room treatment is not recommended unless it is the only available source. Most emergency rooms do not have the equipment to diagnose superficial eye injuries. Your doctor of optometry will be able to determine the amount of damage and decide on a proper treatment plan. Using a biomicroscope with a bright light source (including a blue light to highlight the abrasion after a stain is applied to the tear film) the doctor will be able to detect the size and depth of the injury and if any foreign objects are present in the eye.

Treatment

Fortunately, the corneal epithelium heals very quickly, many times within 24-48 hours. There may be a reason to patch the eye or possibly use a bandage contact lens to increase healing speed and comfort. Usually, an antibiotic drop or ointment will be prescribed to help prevent possible infection. Occasionally over the counter pain medications may be prescribed to help lessen the pain. The patient can help by applying copious amounts of artificial tears and avoiding rubbing the eye. Usually, the doctor will want to see the eye again within 24 hours to re-evaluate the injury. Occasionally, the injury may not heal completely or correctly. This may result in what is called a recurrent corneal erosion. This type of injury can be long-lasting, coming and going over several months or years. There are treatments for these as well and depend greatly on the cooperation of the patient in continuing the treatment plan prescribed by the doctor. If your injury was from living tissue, such as a fingernail or tree branch there is a risk of developing a fungal infection. This is an extremely serious condition but will not present immediately. If the injury that appears to have healed becomes painful again, seek immediate attention.

Prevention

Although the brain has an amazing defense system in place, eye injuries and abrasions can be prevented. Always wear protective eyewear when performing any task that may involve injury to the eye. Sports goggles should be worn when playing contact sports and sports where high-speed objects are used such as baseballs, racquetballs, badminton, soccer, and others. Keeping trees trimmed at above eye level is a simple solution to avoid injuries in well-traveled areas, especially along walkways. If you wear contacts and experience any discomfort, remove the lenses and see your doctor. Never wear contact lenses that have not been prescribed by your doctor.