Managing Corneal Abrasions
BY TIMOTHY T. MCMAHON, OD, FAAO
Corneal abrasions are common events. Contact lenses, fingernails, insects and other "stuff" flying into the eye are common culprits. The standard of care has changed over the past decade.
Traditionally, abrasions had been managed by instilling an antibiotic ointment and then pressure patching the eye using cotton eyepads and loads of adhesive tape. Except in unusual circumstances, this management strategy is no longer the norm.
The management strategy has evolved to using bandage lenses, non-steroidal anti-inflammatory agents, continual antibiotic dosing and avoiding patching.
Minor abrasions: These are abrasions less than 2mm in diameter, have clean looking margins and have a specific and known cause. These exclude contact lens wear, fingernail or paper cut injuries. They can be managed with a topical antibiotic drop (fluoroquiolone) in adults four times per day or topical erythromycin ointment in children three time per day. If the patient is uncomfortable, I include a topical NSAID eyedrop such as Acular (keratolac, Allergan) at a four times per day dosing regimen. OTC acetamin-ophen or oral NSAID can be added for additional pain management. Managing the discomfort and protecting against infection are the two main roles. The eyes will heal themselves.
Major abrasions: For abrasions exceeding 5mm, try a bandage lens first, then you may need mild pressure patching. Prescribe prophylactic antibiotics (qid) as needed. Large abrasions can take many days to heal. Carefully watch the edges of the healing epithelium for signs of heaping or rolling up, which frequently suggest a failure of the epithelium to continue sliding over a denuded area. These areas need to be trimmed if they persist for more than a few days.
Infection risk abrasions: These abrasions are those where you are concerned that there might be an incipient infectious process under way, such as contact lens-induced abrasions and cases where vegetable matter is involved. Insect-induced abrasions could be included in this category as well. Avoid patching for the first 48 hours under virtually all circumstances. Initially treat with frequent antibiotics. For adults, a topical fluorquinolone taken hourly while awake and three or four times through the night the first night and qid after that during healing should cover most problems. If infectious signs develop think about resistance, fungal organisms and Acanthamoeba. For children, erythromycin four to five times per day is normally adequate. Follow-up the next day is necessary. If no evidence of infection is present after 48 hours, drastically reduce the dosing and add a bandage lens for large abrasions or for slowly-healing abrasions.
Basement membrane problems: In cases without abnormal basement membrane deposition, the preemptive use of a bandage lens can be a truly valuable adjunct. Paper cuts, fingernail injuries and corneas with basement membrane dystrophy (map-dot-fingerprint dystrophy) are common circumstances where you should consider recurrent erosions.
In those cases with bandage lenses, try not to remove the lens at follow-up visits. Do not use fluorescein. View the defect through the lens with white light under high power. See the patient 24 hours post treatment, then every one to two days (depending on the problem level) thereafter until the epithelial defect is closed. The abrasion is not fully healed when the epithelial defect is. In order to glue the epithelial cells to the underlying anterior stroma, both epithelial cell type architecture remodeling and new basement membrane deposition under the new epithelium are needed. This can take up to a month. For abrasions involving the visual axis, visual acuity may be reduced during portions or all of the healing process.
Dr. McMahon is an associate professor and Director of the Contact Lens Service at the University of Illinois at Chicago Dept. of Ophthalmology & Visual Sciences.