Traumatic Corneal Abrasion
By BRUCE E. ONOFREY, RPH, OD
Contact lens related ocular trauma is probably the most common yet challenging clinical presentation in primary care optometry. Physical injury to the cornea secondary to contact lens wear is a direct result of physical contact with the lens, debris on or under the lens or poor handling of the lens during insertion or removal. Detecting subtle changes in the corneal epithelium can prevent serious complications.
The delicate surface of the epithelium will usually be affected if it comes into physical contact with the lens. Rigid gas permeable (RGP) contact lenses with poor edge design are most likely to cause edge-related corneal abrasions. The most common cause of abrasion from a soft contact lens tends to be associated with rough removal or torn or cracked lenses. Regular lens inspection is a good preventative practice.
The goals of managing ocular trauma are to: prevent infection; prevent erosion; return to a clear, smooth epithelial surface suitable for resumption of safe and comfortable contact lens wear; and change contact lens parameters that may have contributed to the damage of the corneal surface. It's important to be able to recognize and correct the cause of the injury and to differentially diagnose a simple abrasion from other forms of epithelial pathology.
Small corneal abrasions that cause little discomfort can be managed by temporarily discontinuing lens wear. Warn patients that continued lens wear can delay the healing process and increase the risk of corneal infection. Following lens removal, treat small abrasions with intensive non-preserved lubrication. Larger abrasions accompanied by significant discomfort have a greater potential to become infected, so treat them more aggressively with topical antibiotic therapy as a prophylactic against infectious keratitis.
The use of a pressure patch is controversial and is contraindicated in the presence of an active ocular infectious process. However, in the presence of an effective prophylactic antibiotic, you can safely patch eyes for 24 hours before they are rechecked. It is common for these injuries to resolve within 48 hours. Instead of patching, you can place a disposable thin lens on the eye with a prophylactic antibiotic applied in solution form.
Steroids are not indicated for uncomplicated abrasions because they inhibit healing, promote secondary infection and have the potential to elevate intraocular pressures (IOPs). Complications like recurrent erosion and corneal opacification (scarring) are extremely rare unless the injury is secondary to fingernail abrasion that can occur with the "pinching technique" associated with the removal of soft lenses. If the injury is secondary to a fingernail cut, it can take up to eight weeks for corneal integrity to return to normal levels. Treatment should consist of the extended use of ocular lubricants and hyperosmotic ointment until all epithelial edema has resolved.
Other Types of Ocular Trauma
A staining pattern associated with both rigid and soft contact lens wear, known as corneal wrinkling, is believed to be caused by the physical pressure of the lens fit. Try fitting thinner lenses and switching from PMMA to gas permeable materials.
Another major cause of epithelial damage is the entrapment of material under the contact lens, which is more likely with rigid lenses. Instruct patients to remove their RGPs immediately if a foreign body sensation occurs. If sensation persists after rinsing and replacing the lens, advise them to discontinue lens wear and seek immediate attention. CLS
Dr. Onofrey, editor and author of various ophthalmic texts, practices in Albuquerque, New Mexico.