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The Eye In Chemical

aka Ophthalmology Befuddler 019

A 45 year-old is rushed into the emergency department by the triage nurse. He was working at a building site and got cement into his eyes

Questions

Q1. What is the likely diagnosis?
Answer and interpretation

Chemical injury to the eye — cement contains lime, so this is a potential alkali injury.


Q2. What is the first thing that should be done in this setting?
Answer and interpretation

Suspected chemical injury to the eyes is a true ocular emergency.

Start irrigation of the affected eyes with water even before examining the eyes (unless perforation is suspected).


Q3. What are the features to look for on history and examination?
Answer and interpretation

History:

  • What chemical was involved?
    (alkaline chemicals are particularly dangerous)
  • When did the exposure occur?
  • Was any first aid administered and when?
  • Symptoms? e.g loss of vision, pain, redness, tearing.
  • Associated injuries? e.g. skin exposure

Examination:

  • Measure the pH — stop irrigation for 1 minute to use litmus paper to sample fluid from the forniceal space.
  • Visual acuity — may be decreased
  • Funduscopy — If alkali has penetrated the sclera there may be retinal necrosis.
  • Tonometry — secondary glaucoma may occur

Slit lamp

  • Cornea — Look for corneal clouding.
  • Corneal epithelial defects range from scattered superficial punctate keratopathy (SPK), to focal epithelial loss, to sloughing of the entire epithelium.
  • Other features may be present: hyperemia, chemosis, eyelid edema, hemorrhages, skin burns and an anterior chamber reaction.
  • Assess the degree of vascular blanching, particularly at the limbus, this correlates with severe chemical injury.

Sometimes epithelial defects from chemical burns are slow to take up fluorescein and repeated application may be necessary. If the epithelium has sloughed off leaving a denuded Bowman’s membrane fluorescein uptake may be very limited.


Q4. List examples of chemicals that may cause chemical injury to the eye? Which are more harmful?
Answer and interpretation

Alkaline chemicals are particularly harmful to the eye as they cause colliquative necrosis (liquefactive necrosis).

Alkalis include:

  • lime, mortar and plaster, drain cleaner, oven cleaner, ammonia

Acids (which cause coagulative necrosis) include:

  • toilet cleaners, battery fluid, pool cleaners

Neutral chemicals are treated similarly in the first instance and include:

  • solvents, detergents, aerosols and irritants, e.g. mace, pepper spray.

Q5. What is the management of this man’s condition?
Answer and interpretation

Copious irrigation — for at least 30 minutes, usually about 3L of normal saline or other neutral fluid. Topical anesthesia is often required and should be administered early.

Ideally this should be started as soon as possible following the injury, i.e. prehospital. Contact the poisons centre for advice if further information on the chemical is needed.

Further management includes:

  • analgesia (usually oral) and cycloplegics
  • frequent use of preservative-free artifical tears
  • treatment of secondary glaucoma
  • daily review until the corneal defect has healed, after which steroids may be used by an ophthalmologist to reduce inflammation.
  • Severe chemical burns may require more specialised therapies (e.g. debridement, collagenase inhibitors, ascorbate or citrate for alkali burns, even stem cell transplantation from the contralateral eye) and hospitalisation may be required.

Q6. What is the end-point for irrigation in this setting?
Answer and interpretation

Use litmus paper to check that the pH of the tears have returned to normal (about pH 7.5) after each litre of fluid. Check the other eye or your own for comparison if in doubt. Following (or during) irrigation consult an ophthalmologist urgently.


As soon as you’ve got your cemented eye out of the department you check the triage note of the next patient to be seen: “Eye glued shut with superglue”.

Q7. How will you manage your new patient?
Answer and interpretation

If the eyelids are glued together, separate them gentle traction. If necessary trim the lashes.

Carefully remove the following with fine forceps to reduce the risk of corneal injury:

  • misdirected lashes
  • hardened glue that may rub on the cornea
  • glue stuck to the cornea
  • Treat epithelial defects as corneal abrasions.

If there is glue stuck to the lids or lashes that does not require urgent removal warm compresses qid can be applied to loosen the glue.

Arrange ophthalmology follow up for the next day.


References

OPHTHALMOLOGY BEFUDDLER

Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also a Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.

After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.

He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE.  He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.

His one great achievement is being the father of three amazing children.

On Twitter, he is @precordialthump.

| INTENSIVE | RAGE | Resuscitology | SMACC

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