What Are Corneal Abrasions?
Corneal abrasions are among the most common eye injuries seen by optometrists and emergency departments. They are scratches of the surface tissue of the eye, and can be very uncomfortable, even painful, and cause severe redness and sensitivity to light.
The cornea is a thin, clear lens located at the front and centre of the eye. It's responsible for focusing light through to the retina at the back of the eye, where it is sensed, processed, and sent to the brain. Because the cornea is one of the few parts of the eye that is exposed to the air whenever the eye is open, it is at the greatest risk of injury.
Damage to the cornea can potentially affect vision and requires proper medical attention in order to heal properly and limit any permanent damage. Most corneal abrasions heal completely without affecting vision. However, deep, infected or untreated abrasions can scar the cornea and, in severe cases, permanently impair vision.
A message from our optometrist: "A scratched cornea can be surprisingly painful, even when the injury itself is quite small, because the cornea contains thousands of sensitive nerve endings. Most abrasions heal quickly with the right treatment, but it's important not to ignore persistent pain, blurred vision or light sensitivity. If you wear contact lenses, remove them immediately and have your eyes examined as soon as possible to reduce the risk of infection."
What Causes Corneal Abrasions?
A corneal abrasion can happen in many different ways. If the surface of the eye is scratched or otherwise damaged by any foreign object, big or small, the injury to the eye is called a corneal abrasion
While new and original ways of being injured are always being discovered by the unlucky, the common methods of sustaining a corneal injury include walking into low-hanging tree branches, getting small particular matter like sand or sawdust in the eye, and various types of horseplay, such as wrestling with a pet dog, or having a pillow fight.
Some corneal abrasions occur during a major accident, such as shards of glass entering the eye during a car collision. Others are far less dramatic; a mild eye itch might cause a person to rub their eye, which turns a small speck of annoying matter into an instrument of torture. As the small particle is rubbed into the eye, it creates shallow but painful scratches.
Contact lenses do not protect the eye from injury and if a foreign body becomes trapped beneath the lens, they may actually worsen the abrasion. All but the tiniest of threats would likely penetrate the lens, and possibly even get trapped between the lens and the surface of the eye, making matters even worse.
What Are The Symptoms Of A Scratched Cornea?
The seriousness of corneal abrasion can vary from minor irritation to a more serious medical condition. If you experience any or all of the symptoms below, you should seek prompt medical assistance,
- Pain
- Discomfort
- Redness
- Excessive tearing
- Sensitivity to light
- Headache
- Blurred vision
If you think you may have scratched your cornea, you should arrange an urgent assessment by an optometrist, GP or eye casualty department, particularly if the pain is severe, your vision is reduced, or you wear contact lenses. Microorganisms such as Acanthamoeba are commonly found in tap water, lakes, rivers, hot tubs and soil. Although infection is rare, a scratched cornea—particularly in contact lens wearers—can provide an opportunity for the organism to infect the eye. If left untreated, a corneal abrasion can become infected and lead to a corneal ulcer.
What Is The Treatment For A Scratched Cornea?
If you think you may have a scratched cornea, there a few things you can try at home to remove the foreign object
DO
- Rinse your eye with saline solution
- Remove your contact lenses if appropriate
- Pull your upper lid over your lower lid - this may help to dislodge any foreign object
- Blink slowly several times - this can help to remove small irritants
- Take over-the-counter pain medication like Paracetamol
DO NOT
- Try to remove an object embedded in your eye
- Touch or rub your eye
- Wear contact lenses
- Wear makeup
- Apply an eye patch - the dark, sealed environment will promote the growth of bacteria and increase the risk of infection
If the feeling doesn't go away, or if it worsens, then seek medical attention as soon as possible. Minor abrasions sometimes can be treated with non-preserved lubricating drops to keep your eye moist and comfortable while your eye's natural healing process takes place.
The NHS has some great advice on how to treat an eye injury at home, or when to go to your GP or A&E
To diagnose a corneal abrasion, a doctor will use several different eye drops. The first drops will numb the eye and will provide a great deal of relief for the time being. Next, Fluorescein dye is placed into the eye and viewed under a blue light, making even tiny scratches clearly visible, these drops may temporarily alter vision. The colouring used glows brightly under ultraviolet light, but only has a mild tint under normal lighting. From the patient's perspective, there may be a yellow or orange tint to everything seen through that eye for a short time.
Each instance of a scratched cornea is different, and using his or her professional judgment, the doctor may choose to take a swab sample from the eye and test it for a bacterial infection. Even without this test, it's very likely that antibiotic eye drops will be used as a precautionary measure. They will help to fight any bacteria that may be currently present in the wound, as well as prevent any from developing as it heals.
If there is evidence of infection, antibiotic drops are commonly prescribed. Pain can often be relieved with lubricating drops, oral pain relief and, in some cases, anti-inflammatory eye drops. Steroid eye drops are only used in selected cases under specialist supervision once the cornea has begun to heal. Pain management is also addressed, either through topical Non-Steroid Anti-Inflammatory Drugs (NSAIDs) or standard over-the-counter pain medication such as Paracetamol.
Contact lenses should not be worn while recovering from a scratched cornea. Not only might the lens cause undesired irritation of the wound, it may also introduce and harbour bacteria. Your eye doctor will advise you when you can begin wearing your contact lenses again.
Mild corneal abrasions, especially those treated quickly, are likely to heal with no permanent scarring or changes in visual acuity. However, more serious abrasions, especially those directly in front of the pupil, might have lasting effects.
It's likely that your doctor will recommend a follow-up visit to monitor the healing process. It may be as soon as the next day, or it may be later in the week. The importance of this appointment should not be underestimated. Not all corneal abrasions will heal properly, even after an initial doctor's visit. Catching these issues quickly provides an opportunity to correct the problem before it's too late.
Untreated corneal abrasions are likely to develop an infection and may lead to a corneal ulcer. In this scenario, severe or total vision loss is possible.
How to Prevent a Scratched Eye
Although many causes of corneal abrasions are difficult to prevent, others can be avoided by taking some simple, common-sense precautions, for example, always wearing safety glasses or protective goggles in work environments with airborne debris, particularly in welding environments. Likewise, protective eyewear should be used when doing yard work, using power tools, and playing sports. Be aware, when pruning trees and shrubs, or picking fruit from a bush, it is very easy to get poked in the eye with a branch.
When wearing contact lenses, always follow the instructions for care and handling offered by your Optometrist and make sure that the finger you use for insertion has the nail kept trimmed and is smooth. Never continue wearing a contact lens if your eye becomes painful. Remove the lens immediately and seek professional advice.
