Corneal Abrasion and Ulceration

Basics

Description

  • Corneal abrasions: result from cutting, scratching, or abrading the thin, protective, clear coat of the exposed anterior portion of the ocular epithelium. These injuries cause pain, tearing, photophobia, foreign body sensation, and a gritty feeling (1).
  • Corneal ulceration: break in the epithelial layer of the cornea leading to exposure of the underlying corneal stroma, which results in a corneal ulcer. Superficial ulcers, limited to loss of the corneal epithelium, are the most common form of ulceration (2).
  • Corneal abrasion and ulceration can both lead to impaired vision from scarring.

Epidemiology

Incidence
Eye-related diagnoses make up 8% of total ER visits and are commonly caused by direct/minor trauma. Of those eye-related visits caused by injury, 64% are corneal abrasions (3). Abrasions are the third leading cause of red eye, following conjunctivitis and subconjunctival hemorrhage (4).

Etiology and Pathophysiology

  • Most often caused by mechanical trauma but may also result from foreign bodies: sand and dust, contact lenses wear, or chemical and flash burns
  • Corneal ulceration seen with contact lenses use, HIV, trauma, ocular surface disease. Edema plays a major role in epithelial defect. Edema can lead to trauma, ischemia, and increased intraocular pressure. Excessive fluid disrupts the normal architecture of the epithelial layer (1).
  • Causes of ulcerations include:
    • Gram-positive organisms ~29–53% (Staphylococcus aureus and coagulase-negative Streptococcus are common.)
    • Gram-negative organisms ~47–50% (Pseudomonas most common, followed by Serratia marcescens, Proteus mirabilis, and gram-negative enteric bacilli)
    • Herpes simplex with bacterial superinfection
    • Varicella virus
    • Autoimmune disorder: Sjögren, rheumatoid arthritis, inflammatory bowel disease
  • Increased risk of corneal ulceration in HIV, diabetes mellitus (DM), and immunocompromise
  • Eyelid abnormalities (chronic blepharitis, entropion)
  • Nutritional deficiencies (vitamin A and protein undernutrition)
  • Dry eyes/bullous keratopathy/mucous membrane pemphigoid

Risk Factors

  • History of trauma (direct blunt trauma, chemical burn, radiation exposure, etc.)
  • Contact lenses wear
  • Male gender
  • Age: 20 to 34 years old
  • Job (construction, manufacturing); lack of eye protection

General Prevention

  • Protective eyewear during work (auto mechanics, metal workers, miners, etc.) and during sports
  • With the increasing use of face masks during the COVID-19 pandemic, a case has even been reported of corneal abrasion from removal of face mask with the edge of the mask causing a corneal abrasion (5).

Commonly Associated Conditions

  • Vitamin A deficiency is associated with corneal ulcers.
  • Neuropathy of cranial nerve (CN) V
  • DM, thyroid dysfunction, immunocompromised states, connective tissue disease
  • Critically ill patients who lack blinking reflex or inability to close their eyes and those on intermittent positive pressure from ventilation (6)

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