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

• Corneal abrasions are commonly seen in primary care. Eye-related diagnoses make up 8% of total ER visits. Of those eye-related visits, 45% are corneal abrasions. Abrasions are the third leading cause of red eye, following conjunctivitis and subconjunctival hemorrhage (3).
• Associated with significant morbidity and loss of productivity

Etiology and Pathophysiology

• Corneal abrasions are 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: Contact lenses use, HIV, trauma, ocular surface disease, and ocular surgery increase the incidence. 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 (4).
• Causes of ulcerations include the following:
  • Infection with gram-positive organisms ~29–53% (Staphylococcus aureus and coagulase-negative Streptococcus are common ones.)
  • Infection with gram-negative organisms ~47–50% (Pseudomonas being most common, followed by Serratia marcescens, Proteus mirabilis, and gram-negative enteric bacilli)
  • Herpes simplex with bacterial superinfection
  • Varicella virus
  • Corneal abrasion and eye surgery (cataract, eye transplant)
  • Autoimmune disorder: Sjögren, rheumatoid arthritis, inflammatory bowel disease
• Increased risk of corneal ulceration in HIV and diabetes mellitus (DM) patients and immunocompromised such as cancer
• 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

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