What are Corneal Abrasions?
Corneal abrasions are scratches of the surface tissue of the eye, and are the most common type of eye injury. They can be very uncomfortable, even painful, and cause severe redness and sensitivity to light.
The cornea is a thin, clear lens located front and center on 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 are exposed to the air whenever the eye is open, it is at the most risk of injury.
Damage to the cornea can potentially affect vision, and requires proper medical attention in order to heal property and limit any permanent damage. If not treated properly, or if the damage is serious enough, the chances of visual impairment or blindness in the injured eye are high.
What Causes Corneal Abrasions?
A corneal abrasion can happen any one of a billion different ways. If the surface of the eye is scratched or otherwise
damaged by any foreign object, big or small, the result is 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 saw dust 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. Other times there is no such trauma, only misfortune. 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.
Little protection is offered by contact lenses, which are thin and delicate. 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?
First and foremost, pain and discomfort are the primary signs of a scratched cornea. Few areas of the human body are more sensitive than the surface of the eye, and even the tiniest of particles or scratches can be easily felt. In addition to pain, the other signs and symptoms of a scratched cornea are redness, excessive tearing, sensitivity to light, headache, and blurred vision. If there's any chance that you may have a corneal abrasion, it's important to seek emergency medical treatment immediately. Microorganisms such as Acanthamoeba have been found in tap water and even bottled water, and these pathogens can cause a serious, vision-threatening infection if introduced to an eye with a scratched cornea.
What Is The Treatment For A Scratched Cornea?
At first, it may feel like there is a foreign object in the eye, which there may be, or it may have already been flushed away by tears. In either case, its critical to avoid rubbing the eye, as this won't ever help, and can potentially make the scratch even worse. The best course of action is to flush the eye with saline or contact lens solution. If those aren't available, clean water can be used, but can potentially introduce bacteria or other microbes.
If the feeling doesn't go away, or if it worsens, then plan to seek medical attention as soon as possible. Don't apply an eye patch, as the dark, sealed environment will promote the growth of bacteria, and increase the risk of infection. 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.
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, drops that glow under specific kinds of light are used, which may temporarily alter vision. The coloring used glows brightly under ultra violet 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.
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. Steroid drops may be needed, which will reduce inflammation, and help prevent scarring. Pain management is also addressed, either through more eye drops, or standard prescription pain pills.
Contact lenses should not be worn while recovering from a scratched cornea. Not only might the lens cause undesired irritation of the wound, they may also introduce and harbor bacteria. When it's safe to resume wearing contact lenses will be up to the discretion of your eye doctor.
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 wear 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, that it is very easy to get poked in the eye with a branch. This is a major cause of corneal abrasions.
When wearing contact lenses, always make sure that the finger that you use for insertion has the nail kept trimmed and is smooth.
Author: John Dreyer Optometrist Bsc(Hons), MCOPTOM, DipCLP
Created: 1 Jul 2016, Last modified: 17 Jul 2019