Countering Corneal Abrasions
BY WILLIAM L. MILLER, OD, PHD, FAAO
Corneal abrasions represent one of the more frequent maladies that we face in ophthalmic practice. Offending agents can range from fingernails to mascara wands to box flaps. Corneal abrasions have also resulted from paintball games (Listman, 2004) and from car accidents with airbag deployment (0.05 percent vs. 0.04 percent without, Duma et al 2002). Watch abrasions resulting from tree branches and the like for fungal infection.
No Two Are the Same
Treating corneal abrasions can become complicated and require multiple therapies. You often must tailor management to individual patients based on several factors that may include size and position of the abrasion, suspected cause and health of the patient.
Assess the precise cause and depth of the lesion. Rule out any suspected high velocity penetration, which may influence treatment and in some cases requires discussing the possibility of lingering scars. Instilling a drop of topical anesthetic often helps with biomicroscopy and makes measuring visual acuity easier.
Using a sterile, saline-soaked cotton-tipped applicator, kimura spatula or golf spud, remove any necrotic epithelial tissue around the borders of the abrasion. This removes any impediments to epithelial healing.
Pressure patching was once a primary treatment because it reduces pain, but it's contraindicated in contact lens wearers who have abrasions (because of increased incidence of Pseudomonas keratitis infection) and in patients who have vegetative matter injuries. Other treatments that relieve pain and are less cumber some and intrusive to patients have replaced pressure patching.
Managing the Patient
Your treatment goals are to protect the cornea, decrease pain, prevent opportunistic infection and improve vision. You can place a few drops of a nonsteroidal anti-inflammatory topical medication (diclofenac [Voltaren, Novartis] or ketolorac [Acular, Allergan]) on the ocular surface to decrease inflammation and help manage pain. You can also manage pain with over-the-counter analgesics such as ibuprofen. Consider a topical steroid only in cases of severe inflammation because steroids have a detrimental effect on epithelial mitosis and healing.
Prescribe an NSAID three to four times each day, concomitant with a topical antibiotic. Fit a bandage contact lens (BCL) over the abrasion to protect the fragile epithelial cell sheet and to cover the exposed corneal nerve endings. Many practitioners choose a silicone hydrogel BCL to boost oxygen permeability.
Depending on the severity of the abrasion and anterior chamber response, you may need to apply a cycloplegic agent (cyclo pentolate 1%, b.i.d.) for comfort. Patients can also use tear supplements, preferably preservative-free, at bedtime for lubrication and to facilitate healing.
To prevent opportunistic infection, administer a topical antibiotic drop three to four times each day. I recommend trimethoprim and polymyxin (Polytrim, Falcon Pharmaceuticals, Ltd.) because many aminoglycosides are toxic to the corneal epithelium and may retard epithelial healing.
Fourth-generation fluoroquinolones (particularly preservative-free) are perhaps overkill, but may be the most logical choice to apply to a fragile, healing cornea in the presence of a soft lens.
See the patient within 24 hours and monitor healing. Continue therapy until the cornea is 90 to 95 percent resolved. Before removing the BCL, apply extra lubrication to prevent adhesion of fragile epithelial cells to the lens and resultant secondary abrasions. Monitor any non-healing abrasion for possible infection or alternative therapies and/or corneal specialist consult.
Dr. Miller is on the faculty at the University of Houston College of Optometry. He is a member of the American Optometric Association and serves on its Journal Review Board. You can reach him at email@example.com.