Abrasion, Etiologies, Signs and symptoms, Differential diagnosis, management

1. ABRASION
Raju Kaiti
Optometrist
Dhulikhel Hospital, Kathmandu University Hospital
Corneal abrasion is a medical condition involving the loss of the surface epithelial layer of the
eye's cornea. A corneal abrasion is a defect in the surface of the cornea that is limited to the most
superficial layer, the epithelium, and does not penetrate the Bowman membrane.
Corneal abrasion results from physical or chemical trauma. Potential causes of corneal abrasion
include the following:
 Injury (e.g., fingers, fingernails, paper, mascara brushes, tree branches, self-inflicted rubbing,
pepper-spray exposure, automotive frontal air bags )
 In persons with trachoma, the constant corneal abrasion by lashes and inadequate tears dust,
sand, or debris
 Extended contact lens wear
 Ocular foreign bodies embedded under an eyelid or Corneal foreign bodies
 Iatrogenic - Unconscious patients, accidental injury by health care workers, improper eyelid
patching in patients with Bell palsy, and other neuropathies in which the eyelid cannot be
closed voluntarily
 UV keratitis - History of exposure to electric arc welding or tanning beds without proper eye
protection, history of prolonged exposure to bright sunlight without sunglasses (e.g., snow
blindness)
 Eyelid margin injuries and avulsions
 Punctal and canalicular lacerations
Contact lens trauma
Contact lens–induced epithelial defects or direct trauma during lens insertion or removal can
cause corneal abrasions. Abrasions occur more frequently with rigid lenses than with other
lenses, possibly because of their small diameter and the sharp corneal defects they cause.
Corneal abrasions due to soft lenses are observed most frequently with tight or extended-wear
lenses. In these situations, acute epithelial hypoxia impairs attachment of the epithelium to the
Bowman membrane.
Sports-related injury: Corneal abrasions can occur in almost all sports. They most frequently
occur in young people.
Eyelid surgery: In patients undergoing eyelid surgery, corneal abrasion can result from sutures
inadvertently placed through the tarsus or conjunctival surface.
Argon lasertrabeculoplasty: Corneal abrasion is one of the complications of argon laser
trabeculoplasty.
Tonometry: The plunger and/or applanation probe can cause corneal abrasion if the eye or
tonometer moves during measurement.

2. Signs:
 Conjunctival injections or redness depending upon the extent of abrasion
 Moist or watery eye
 Closing or squeezing of the affected eye
Symptoms:
 Patients with a corneal abrasion typically complain of eye pain and an inability to open
the eye because of foreign body sensation. The severity ranges from a mild foreign body
sensation in cases of small abrasions to excruciating pain in large abrasions.
 Often, patients are too uncomfortable to work, drive, or read, and the pain frequently
precludes sleep. Multiple attempts by the patient to "wash out" the eye can further disrupt
the epithelial surface.
 Photophobia, especially if secondary traumatic iritis is present, pain with EOM
movement, or blurred vision.
 Excessive tearing may occur.
 Conjunctival injection and eyelid swelling may be present.
 The patient's history typically includes trauma to the eye due to either a foreign object or
a contact lens. Toxic chemicals (e.g., ear drops) accidentally instilled into the eye can
cause corneal abrasions. Symptoms typically begin instantly after trauma occurs and can
last minutes to days, depending on the size of the abrasion.
 Blurry or reduced vision
Differential Diagnosis:
 Acute Angle-Closure Glaucoma
 Blepharitis
 Corneal Foreign Body
 Corneal Ulceration and Ulcerative Keratitis in Emergency Medicine
 Dystrophy, Map-dot-fingerprint
 Emergent Treatment of Acute Conjunctivitis
 Entropion, Trichiasis
 Ectropion
 Epidemic Keratoconjunctivitis
 Iritis and Uveitis

3. Approach:
Strongly consider use of a slit lamp examination with fluorescein to diagnose a corneal abrasion
in ambulatory patients; without the magnification of the slit lamp, small abrasions can be missed.
If ocular penetration with a retained foreign body is suspected, such as in a high-velocity injury
(e.g., lawn mower, string trimmer, hammering metal), then an ocular CT scan, ocular MRI (if the
object is nonmetallic), or both are indicated.
A topical anesthetic (i.e. proparacaine, xylocaine, and tetracaine) may facilitate the slit-lamp
examination. Severe photophobia that causes blepharospasm may require instillation of a
cycloplegic agent (i.e., cyclopentolate [Cyclogyl], homatropine) 20-30 minutes prior to
examination.
Perform fluorescein instillation and examination with cobalt blue filter.
Management:
Infection Prevention: de-epithelialized cornea is more susceptible than intact cornea to
infection. Antibiotics should be continued until the patient is asymptomatic.
Pain Relief: The pain of corneal abrasions may be severe and should be treated with non-
steroidal anti-inflammatory drops and, if necessary, a soft bandage contact lens. Narcotic
analgesia is occasionally required on a short-term basis. These are continued until the pain
decreases to the point that it can be managed with over-the-counter analgesics.
Instillation of a long-acting cycloplegic agent can provide significant relief for patients with
marked photophobia and blepharospasm. These agents relax any ciliary muscle spasm that may
cause a deep, aching pain and photophobia. Cycloplegic agents are mydriatics; therefore, to
prevent an episode of acute angle closure glaucoma, ensure that the patient does not have
narrow-angle glaucoma.
Patching: It provides rest to the eyes and prevents possible friction and further abrasions.
Patching eye with cycloplegic agent and antibiotic ointment will help the patient in pain relief,
infection control and resting the eye.
Prevention of Corneal Abrasion
Persons who work in high-risk occupations such as auto mechanics, metalworkers, or miners
should wear protective eyewear. People who participate in contact sports such as hockey,
lacrosse, or racquet sports such as squash or racquetball should always wear protective eyewear.
Eye protection is also important for patients whose work or recreation increase the risk of
corneal abrasion or ultraviolet light exposure (e.g., farming, hiking through areas of tall foliage,
skiing).
To prevent corneal abrasion in patients who are unconscious or who cannot voluntarily close
their eyelids (e.g., because of Bell palsy or other neuropathies), tape the eyelids closed. Patients
who wear contact lenses should make sure they fit properly and change them accordingly.
Prognosis:

4. The prognosis is usually excellent, with full recovery of vision if treatment is prompt; however,
untreated corneal abrasions can lead to blinding corneal ulcers.
Some deep abrasions (e.g., those involving the corneal stromal layer) in the central visual axis
(i.e., the central area of the cornea directly over the pupil) heal but leave a scar. In these
instances, a permanent loss of visual acuity may occur. Healing of minor abrasions is expected
within 24-48 hours. Extensive or deep abrasions may require a week to heal.
From Optometry point of view, patient can be helped with sunglasses to cope the photophobia.
Cycloplegic gents can be prescribed for relieving pain. Then as the patient feels a bit better, we
have to perform detail slit lamp evaluation with fluorescein staining and confirm the diagnosis.
For small abrasions regular antibiotic drops/ointments and lubricating drops with rest should be
advised. For some abrasions, eye padding might be required. Counseling about abrasion, its
causes and prevention and safety precautions should be shared with them. Above mentioned all
treatments can be effectively given by an optometrist.