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.
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.
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 email@example.com.