Chemical Ocular Injury Lecture Notes

Chemical Ocular Injury

Why It Is an Emergency

Chemical ocular burns are true ophthalmic emergencies.
Major complications include:
- Corneal scarring with permanent visual loss.
- Corneal perforation with possible loss of the eye.
Immediate irrigation takes priority over all initial assessment steps, including visual-acuity testing.

Begin irrigation immediately.
- Use 1 to 2 L of normal saline as the initial irrigation volume described in the source.
- Start at the scene when possible and continue in the emergency department.
Instill a topical anesthetic to facilitate ongoing irrigation.
Continue irrigation for at least 30 minutes.
Use sterile normal saline or another isotonic solution.
- Delivery options include manual instillation, eye-irrigation bottles, or a Morgan Lens with an isotonic IV solution.

Alkali injuries are more common than acid injuries.
- Typical sources include household cleaning agents and building materials.
- Particularly serious exposures include ammonia, lye, and concrete.
Alkali injuries tend to be more severe.
- They cause liquefaction necrosis.
- Protein denaturation and fat saponification permit deeper tissue penetration.
Acid injuries cause coagulation necrosis.
- Denatured protein forms a coagulum that limits further tissue penetration.

After at least 30 minutes of irrigation, assess ocular pH.
- Touch litmus paper to the inferior conjunctival fornix.
If pH is greater than 7.4, continue irrigation until pH remains neutral for 30 minutes after irrigation stops.
The source describes the endpoint as a neutral pH; confirm local ophthalmology and emergency department protocols for operational thresholds.

Do not delay irrigation for examination or visual testing.
Alkali exposures require particular urgency because of deep tissue penetration.
Continue irrigation and reassess pH before proceeding to the detailed eye examination.
Look actively for retained particles beneath the eyelids.