Caustic keratoconjunctivitis: Difference between revisions
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**Concerning due to co-location of corneal stem cell layer
**Concerning due to co-location of corneal stem cell layer
**Re-epitheliazation relies on migration of limbal stem cells
**Re-epitheliazation relies on migration of limbal stem cells
*Roper-Hall classification
*Roper-Hall classification<ref>Gupta N et al. Comparison of Prognostic Value of Roper Hall and Dua Classification Systems in Acute Ocular Burns. Br J Ophthalmol. 2011;95(2):194-198. http://www.medscape.com/viewarticle/739100.</ref>
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Revision as of 00:57, 3 April 2016

Background

  • Chemical burn to eye
  • Alkali injuries are more severe than acidic injuries
  • Ocular alkali exposures are an ophthalmologic emergencies

Caustics

  • Substances that cause damage on contact with body surfaces
  • Degree of injury determined by pH, concentration, volume, duration of contact
  • Acidic agents cause coagulative necrosis
  • Alkaline agents cause liquefactive necrosis (considered more damaging to most tissues)
  • Corrosive agents have reducing, oxidising, denaturing or defatting potential

Alkalis

  • Accepts protons → free hydroxide ion, which easily penetrates tissue → cellular destruction
    • Liquefactive necrosis and protein disruption may allow for deep penetration into surrounding tissues
  • Examples
    • Sodium hydroxide (NaOH), potassium hydroxide (KOH)
      • Lye present in drain cleaners, hair relaxers, grease remover
    • Bleach (sodium hypochlorite) and Ammonia (NH3)
      • Cleaning products such as oven cleaners, swimming pool chlorinator
      • Household bleach ingestion (4-6% sodium hypochlorite) rarely causes significant esophageal injury[1][2]

Acids

  • Proton donor → free hydrogen ion → cell death via denatured protein → coagulation necrosis and eschar formation, which limits deeper involvement
    • However, due to pylorospasm and pooling of acid, high-grade gastric injuries are common
      • Mortality rate is higher compared to strong alkali ingestions
  • Can be systemically absorbed and → metabolic acidosis, hemolysis, AKI
  • Examples
    • Hydrochloric acid (HCl), hydrofluoric acid (HF), Sulfuric acid (H2SO4), Phosphoric acid, Oxalic Acid, Acetic acid
      • Found in: auto batteries, drain openers, toilet bowl, metal cleaners, swimming pool cleaners, rust remover, nail primer

Clinical Features

  • Symptoms - Severe pain, blepharospasm, reduced visual acuity
  • Alkali injuries can cause elevated IOP.[3]
  • Evaluate ocular pH (normal is 7.0-7.2)
  • Appearance
    • Conjunctival injection OR blannching
    • Chemosis, hemorrhage, epithelial defects
    • Corneal loss OR edema
  • Perilimbal ischemia = white ring around iris
    • Concerning due to co-location of corneal stem cell layer
    • Re-epitheliazation relies on migration of limbal stem cells
  • Roper-Hall classification[4]
Grade Cornea Appearance Limbal Ischemia Prognosis
I Clear None Good
II Hazy/iris details visible <1/3 Good
III Opaque/iris details obscured 1/3-1/2 Guarded
IV Opaque/iris details obscured >1/2 Poor

Differential Diagnosis

Caustic Burns

Conjunctivitis Types

Unilateral red eye

^Emergent diagnoses ^^Critical diagnoses

Management

  1. Irrigation
    • Immediate irrigation is the most important treatment for caustic occular injury, and should be started before comprehensive evaluation
    • Irrigate affected eye(s) with copious amounts of fluid (no consensus on volume or length of time)[5]
    • NS, LR, or BSS (Buffered Saline Solution) preferred in the hospital setting[6], but tap water is acceptable, esp in pre-hospital setting.
    • Goal is to remove caustic agent and restore normal ocular pH (7.0-7.2)
    • Do NOT attempt to neutralize pH by adding base to an acidic burn or visa versa
    • Use of morgan lens or eyelid speculum will assist with getting more fluid in contact with cornea.
      • Apply anesthesia to eye, place lens under upper eyelid, followed by lower eyelid
  2. Remove particulate matter
    • Evert both lids, remove any visible particulate matter with cotton-tipped applicator
  3. Anesthesia
    • Apply topical anesthetic (e.g. tetracaine) to help with discomfort.
    • Further pain control measures
      • Cycloplegics (e.g. atropine, cyclopentolate) can assist in pain control
      • Encourage generous use of artificial tears, other lubricating drops
      • PO analgesia as needed
  4. Antibiotics
    • Erythromycin ophthalmic ointment QID for minor burns
    • For more severe burns, topical fluoroquinolone is warranted.
  5. Control inflammation
    • Topical steroids - prednisolone 1% QID for 1 week[7]
    • Should not be continued for more than 10 days to avoid corneal breakdown.[8]
  6. Ophtho consultation for all but minor burns (Severe exposures may require debridement or other surgical intervention)

Disposition

  • Admit all pediatric patients.
  • Admit all patients with corneal haziness or opacity or limbal ischemia (paleness at limbus)
  • Discharge with 24hr ophthalmology follow-up if only has corneal epithelial injury (fluorescein uptake)

Prognosis

  • Determined by the extent of injury at the limbus and area/depth of injury to cornea

See Also

References

  1. ↑ Wasserman RL, Ginsburg CM. Caustic substance injuries. J Pediatr. 1985;107(2):169-174. doi:10.1016/s0022-3476(85)80119-0
  2. ↑ Harley EH, Collins MD. Liquid household bleach ingestion in children: a retrospective review. Laryngoscope. 1997;107(1):122-125. doi:10.1097/00005537-199701000-00023
  3. ↑ Lin, M.P., et al., Glaucoma in patients with ocular chemical burns. American journal of ophthalmology, 2012. 154(3): p. 481-485 e1.
  4. ↑ Gupta N et al. Comparison of Prognostic Value of Roper Hall and Dua Classification Systems in Acute Ocular Burns. Br J Ophthalmol. 2011;95(2):194-198. http://www.medscape.com/viewarticle/739100.
  5. ↑ Chau JP, Lee DT, Lo SH. A systematic review of methods of eye irrigation for adults and children with ocular chemical burns. Worldviews Evid Based Nurs. 2012 Aug;9(3):129-38.
  6. ↑ Herr RD, White GL Jr, Bernhisel K, Mamalis N, Swanson E. Clinical comparison of ocular irrigation fluids following chemical injury. Am J Emerg Med. 1991 May;9(3):228-31.
  7. ↑ Dohlman, C.H., F. Cade, and R. Pfister, Chemical burns to the eye: paradigm shifts in treatment. Cornea, 2011. 30(6): p. 613-4.
  8. ↑ Donshik, P.C., et al., Effect of topical corticosteroids on ulceration in alkali-burned corneas. Archives of ophthalmology, 1978. 96(11): p. 2117-20.
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