Corneal ulcer

A corneal ulcer is also often referred to as bacterial keratitis, although these terms are not directly interchangeable because a cornea may harbor a bacterial infection (i.e bacterial keratitis) without having a loss of tissue (an ulcer), and a cornea may have an ulcer without a bacterial infection.

Background

Eye anatomy.

• Major cause of impaired vision and blindness worldwide
• Break in epithelial layer allows infectious agents to gain access to the underlying stroma
• Risk factors include: incomplete lid closure (e.g. secondary to Bell's palsy) and soft contact lens use (especially sleeping in contacts)

Causes

• Bacteria
  • Pseudomonas
  • Strep pneumo
  • Staph
  • Moraxella
• Viruses
  • Herpes simplex
  • Varicella-zoster
• Fungi
  • Candida
  • Aspergillus
  • Penicillium
  • Cephalosporium

Clinical Features

Corneal ulcer without infection

Corneal ulcer infected with Pseudomonas spp.

• Redness and swelling of lids and conjunctiva
• Ocular pain or foreign body sensation
• Decreased visual acuity (if located in central visual axis or uveal tract is inflamed)
• Photophobia
• Gray/white corneal lesion (will have fluorescein uptake)
• Requires careful physical exam as 40% of lesions < 5mm
• Hypopyon may be present
• Iritis signs may be present (miotic pupil, consensual photophobia)

Complications

• Corneal scarring
• Corneal perforation
• Anterior/posterior synechiae
• Glaucoma
• Cataracts

Differential Diagnosis

Unilateral red eye

• Nontraumatic
  • Acute angle-closure glaucoma^
  • Anterior uveitis
  • Conjunctivitis
  • Corneal erosion
  • Corneal ulcer^
  • Endophthalmitis^
  • Episcleritis
  • Herpes zoster ophthalmicus
  • Inflamed pinguecula
  • Inflamed pterygium
  • Keratoconjunctivitis
  • Keratoconus
  • Nontraumatic iritis
  • Scleritis^
  • Subconjunctival hemorrhage
• Orbital trauma
  • Caustic keratoconjunctivitis^^
  • Corneal abrasion, Corneal laceration
  • Conjunctival hemorrhage
  • Conjunctival laceration
  • Globe rupture^
  • Hemorrhagic chemosis
  • Lens dislocation
  • Ocular foreign body
  • Posterior vitreous detachment
  • Retinal detachment
  • Retrobulbar hemorrhage
    • Ocular compartment syndrome
  • Traumatic hyphema
  • Traumatic iritis
  • Traumatic mydriasis
  • Traumatic optic neuropathy
  • Vitreous detachment
  • Vitreous hemorrhage
  • Ultraviolet keratitis

^Emergent diagnoses ^^Critical diagnoses

Evaluation

• Clinical diagnosis
• Grey white corneal lesion on gross vs slit lamp examination
• Fluorescein uptake
• Visual Acuity
• Topical anesthetic (ie proparacaine or tetracaine) may assist in patient cooperation with exam once open globe excluded.
  • Repeated doses or Rx for topical anesthesia is contraindicated given concerns for impaired healing

Corneal abrasion vs. corneal ulcer

Characteristic	Corneal abrasion	Corneal ulcer
History	*Acute pain immediately after injury	*Delayed pain frequently 2-3 days or more after initial event
Lesion viewable on fluorescein exam	*Yes	*Yes
Lesion viewable on white light exam	*No	*Yes
Lesion morphology	*Frequently linear, punctate, patterned, and/or irregular	*Commonly circular

Management

• Emergent ophtho consultation
• Topical antibiotics
  • Vigamox 1 drop qhour OR
  • Ciprofloxacin
    • 2gtt q15 min x6 hours, then q30min x18h, then q1h x1 day, then q4h x12d
• Consider antiviral or antifungal if high suspicion for viral or fungal cause (rare)
• Cycloplegic may help if iritis present
  • Cyclopentolate 1%
• Do not patch the eye
• Tdap update is not strictly required
• Consider gentle irrigation and if there is suspicion for contamination

Disposition

• Discharge with ophtho followup within 24-48 hours

See Also

• Bacterial keratitis