A scratched cornea, also called a corneal abrasion, is a common injury involving the eye. It is often caused by a foreign body — such as a contact lens, tree branch, or flying debris from a power tool — that scratches the surface of the eye. Most corneal abrasions are minor injuries and heal rapidly. However, retained foreign bodies can cause infection, swelling, or scarring, so it is important to see your eye doctor after an eye injury.
What Causes a Scratched Cornea?
Scratches or scrapes on the surface of the eye can also be caused by chemical irritation from cosmetics or fluids in the eye, excessive UV light exposure (such as may be caused by sunlight, sun lamps, welding torches, snow, or water reflections), eye infection, and contact lens use.
Contact Lens Related Scratched Cornea
Contact lens wearers are at greater risk for corneal abrasions if they wear their lenses incorrectly. Scratches on the surface of the eyes can be caused by poorly fitting lenses, wearing lenses when the eyes are dry, lenses that have been incompletely cleaned and have particles attached to them, lenses left in the eyes too long, lenses left in inappropriately during sleep, and forceful or careless removal of lenses.
Contact lenses may also facilitate the development of infection. If you wear contact lenses and have a corneal abrasion, your doctor will most likely refer you to an ophthalmologist. If you wear contact lenses, a scratched cornea can quickly progress to corneal scarring or perforation if not adequately treated.
Symptoms of a Scratched Cornea
A scratched cornea often feels as if there were something in the eye. Symptoms may include:
- Eye Pain
- Redness (due to inflamed blood vessels on the surface of the eye)
- Swelling of the eye and eyelid
- Blurred vision
- Light sensitivity (photophobia)
Scratched Cornea Diagnosis
Emergency evaluation and treatment is necessary if you are suffering from a penetrating foreign body and are experiencing a noticeable loss of vision. For any eye injury, your eye doctor will perform a complete eye examination, during which he or she will:
- Examine the eye with a microscope for any abnormalities such as small leaks of fluid from the eye and puncture marks
- Apply eye drops containing a dye (fluorescein) that glows under special lighting to look for corneal abrasions and foreign bodies
If an intraocular foreign body is suspected, your doctor may recommend an imaging study, such as a computed tomography (CT) scan.
A corneal abrasion examination will also enable your doctor to determine whether another condition may be causing the symptoms, and whether that condition might affect treatment and healing of the injured eye. The differential diagnosis of corneal abrasion includes the following: corneal ulcer, retained corneal foreign body, conjunctivitis, acute angle-closure glaucoma, dry eye syndrome, recurrent erosion syndrome, uveitis, and fungal or bacterial eye infection (keratitis).
Scratched Cornea Treatment
A scratched cornea should be treated like any eye injury. Follow first aid guidelines for an eye emergency and see your doctor if an object is stuck in your eye. Do not try removing it yourself. Any foreign material should be removed by a medical professional as soon as possible. This helps prevent infection. Sometimes a surgical procedure is needed to remove the foreign body, which is another reason why it is important to seek medical help immediately. For a chemical eye injury, thoroughly flush the eye with water for at least 30 minutes and then go to the nearest emergency medical facility.
Your doctor will consider many factors when determining what treatment you need. Treatment depends on the severity of the injury. Eye pain may be treated with over-the-counter oral pain medications or analgesic eye drops (non-steroidal anti-inflammatory drugs), but severe eye pain may require a prescription narcotic. Although your doctor may use a topical anesthetic during your examination, excess use of these agents can retard healing and cause corneal damage.
For a simple corneal abrasion, your doctor will prescribe a standard antibiotic to protect against infection. This antibiotic will usually be administered in the form of drops or an ointment. You will be advised to continue the antibiotic treatment for three to five days and discontinue it after you have been symptom-free for at least 24 hours. If you have a contact lens-related corneal abrasion or a scratch caused by organic matter (such as a tree branch), your doctor may prescribe a more potent antibiotic, antifungal agent, or anti-pseudomonal agent.
Eye patches were once used to treat corneal abrasions, but studies have shown that patches do not alleviate pain or promote healing. A temporary bandage contact lens may be used for these purposes. Your doctor may recommend not wearing cosmetic contact lenses until the eye has healed.
Prognosis of a Scratched Cornea
The size of a corneal abrasion usually determines the time it will take to heal. Small, uncomplicated abrasions usually heal in two to three days, whereas larger abrasions that affect more than half of the surface area of the cornea may take four to five days. According to American Family Physician, “In patients with traumatic corneal abrasions who [were] treated in ophthalmology offices, 28 percent had recurrent symptoms up to three months after the injury.”
Complications of a Scratched Cornea
Common complications include recurrent corneal erosion, eye pain weeks after healing, secondary infection, and corneal ulcers.
How to Prevent a Scratched Cornea
While it is impossible to protect your eyes from injury completely, you can take steps to avoid trauma to the eye. Wearing protective eyewear during any activity that can cause particles to enter the eye is the best way to prevent eye injury. It is also advisable to wear sunglasses to screen UV light.
Remember to be careful when using household cleaners. Some household products contain chemicals that are dangerous if they come into contact with the eyes, and may even cause serious injury or blindness.
If you wear contact lenses, you should work with your eye doctor to make sure your lenses fit correctly. Proper contact lens use can prevent potential problems. Seeing an eye doctor regularly is also important to good eye health.
- Corneal Abrasions and Foreign Bodies, The Merck Home Health Handbook, http://www.merckmanuals.com/home/injuries_and_poisoning/injuries_to_the_eye/corneal_abrasions_and_foreign_bodies.html
- Ms S. M. Quinn, Dr J. Kwartz, “Emergency Management of Contact Lens Associated Corneal Abrasions,” (Emergency Medicine Journal, 2004) 21:755. http://emj.bmj.com/content/21/6/755.2.full
- S. A. WILSON, MD and A. LAST, MD, “Management of Corneal Abrasions,” (American Family Physician, 2004) 70(1):123-128. http://www.aafp.org/afp/2004/0701/p123.html