Corneal Abrasion

A corneal abrasion is a traumatic loss of corneal epithelium, with the superficial basement membrane usually intact. It is one of the commonest presentations to an eye emergency service.

• Causes: fingernails and tree branches, contact lens wear and removal, foreign bodies (including under the upper lid), chemical splash, spontaneous (recurrent erosion), and thermal or ultraviolet injury (welding flash, snow blindness).
• Epithelium regenerates quickly, with small abrasions healing in 24 to 72 hours.
• Danger signs: contact lens wearers (risk of Pseudomonas keratitis), organic matter injury (fungal risk), high velocity injury (penetrating globe injury), and immunosuppression.

• Sudden severe pain, foreign body sensation, tearing, photophobia, blepharospasm, redness, and blurred vision.
• Fluorescein shows an area of epithelial loss with linear vertical scratches under the upper lid in the presence of a retained foreign body.
• Mild anterior chamber reaction with a traumatic iritis in large abrasions.

• History: mechanism, time, contact lens wear, and the nature of the foreign body.
• Visual acuity, slit lamp with fluorescein under cobalt blue light, lid eversion to exclude foreign body, and anterior chamber examination.
• Seidel test and detailed examination to exclude penetrating injury; CT of the orbit for suspected intraocular foreign body (avoid MRI when metal is suspected).
• Look for infiltrate (infection) and for dendritic pattern.
• Tetanus status is checked for soil contaminated injuries.

• Remove a corneal foreign body with a sterile needle or spud under topical anaesthesia (proxymetacaine 0.5 percent) at the slit lamp, and remove a rust ring with a burr or needle.
• Do not prescribe topical anaesthetic for home use (it delays healing and can cause toxic keratopathy and melt).
• Topical antibiotic prophylaxis: chloramphenicol 0.5 percent drops 4 times daily or 1 percent ointment 3 to 4 times daily for 5 to 7 days; in contact lens wearers use a fluoroquinolone (ofloxacin 0.3 percent or moxifloxacin 0.5 percent four times daily) to cover Pseudomonas, and examine daily.
• Cycloplegia for large abrasions or iritis: cyclopentolate 1 percent single dose (action 24 hours) or homatropine 2 percent.
• Analgesia: paracetamol 1 g every 6 hours; ibuprofen 400 mg every 8 hours; short course topical NSAID (diclofenac 0.1 percent or ketorolac 0.5 percent) four times daily for up to 48 to 72 hours has been shown to relieve pain.
• Do not patch the eye (it does not accelerate healing and raises infection risk); a bandage lens may be used for large defects in selected, reliable patients.
• Advice: no contact lens until fully healed (at least a week after healing), return urgently for worsening pain, discharge, or reduced vision, and review at 24 to 48 hours for large abrasions, lens wearers, or high risk cases.
• Recurrent corneal erosion (after healing, awakening pain and tearing on eye opening in the morning from poor basement membrane adhesion):
  • Lubricants (preservative free drops 4 to 6 times daily and ointment at night) for at least 3 to 6 months.
  • Hypertonic saline 5 percent drops four times daily and ointment at night.
  • Bandage contact lens for several weeks.
  • Oral doxycycline 50 mg to 100 mg twice daily with topical corticosteroid (fluorometholone 0.1 percent twice daily for 2 to 3 weeks) for 6 to 12 weeks to reduce matrix metalloproteinase activity.
  • Anterior stromal puncture, epithelial debridement, or phototherapeutic keratectomy for failure.
• Complications: infection and ulceration, recurrent erosion, scarring, and traumatic iritis.