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The
Fine Points of Managing Abrasions
BY
WILLIAM TOWNSEND, OD
Corneal abrasions
are among the more common presentations we see. Smaller abrasions of
limited
size or area typically respond quickly to cycloplegics, prophylactic antibiotics
and overnight
patching. Larger, more extensive abrasions often heal more slowly, have a higher
incidence of significant inflammation and pose a greater risk for developing subsequent
recurrent corneal erosion. Understanding corneal anatomy and physiological response
to injury can help us make informed decisions in managing individuals who have significant
corneal abrasions.
Find the Cause
In evaluating a patient presenting with any anterior segment injury,
history is important to understand how it occurred and to determine which portions
of the eye require immediate attention. Shearing injuries (fingernail injuries,
paper cuts) have an increased risk for developing recurrent erosion. Injuries involving
vegetation are prone to fungal infection. High-speed particles may cause both abrasion
and intraocular foreign body. Blunt trauma may cause macular edema or retinal tears
in addition to corneal abrasion.
Take Away the Sting
In evaluating patients who have abrasions, especially those of
more than a few hours duration, inflammation may render the victim highly photophobic
and unable to voluntarily open his eyes. These patients appreciate and benefit from
topical anesthesia and cycloplegia. Observe the margins of the abrasion for elevation
or a puckered appearance. This indicates that the area of epithelial separation
from underlying tissue extends beyond the border of the abraded area. You can confirm
this using fluorescein stain.
Initial Treatment
It's unlikely that corneal epithelial tissue torn away from basement
membrane/Bowman's layer will adhere well to the underlying tissue. Removing this
tissue ultimately promotes re-epithelialization and healing.
We've found that instilling a topical NSAID prior to foreign body
removal or debridement significantly reduces patient discomfort after the procedure.
Subsequent to instilling a topical anesthetic, gently debride the tissue with a
Kimura spatula or similar instrument until the epithelium firmly adheres to underlying
tissue.
Long-term Strategies
High-Dk silicone hydrogel lenses have been successfully used for
long-term management of severe abrasions. You can enhance prophylactic antibiosis
though the short-term use of topical antibiotics. Because the bandage lens absorbs
these medications and preservatives such as BAK can interfere with corneal healing,
we prefer to use non-preserved products.
Verma and Ehrenhaus (2005) state that bandage lens treatment,
when used for this indication, must be continued for eight to 26 weeks to facilitate
repair of the corneal epithelial basement membrane. We typically have the patient
wear a bandage lens for one to two months. After we remove the lens, we strongly
recommend use of a topical hypertonic ointment for a minimum of three months. We
encourage patients to immediately report any discomfort, particularly if it occurs
immediately after awakening, as this is a sign of recurrent corneal erosion.
Worth the Effort
Individuals who have corneal abrasions represent a group of patients
who are particularly appreciative of our services. Remember these basic concepts
to effectively treat and manage corneal abrasions in your patients. CLS
Dr. Townsend is in private
practice in Canyon, Texas, and is a consultant at the Amarillo VA Medical Center.
E-mail him at drbill1@cox.net.
Contact Lens Spectrum, Issue: December 2005