Ocular Trauma and Emergencies
This section covers ocular trauma and emergencies: chemical injury, open globe, hyphema, retrobulbar haemorrhage, and intraocular foreign body. The exam tests immediate priorities.
Core rules and concepts
- Chemical burns are irrigated immediately with copious saline or Ringer's solution; check pH and continue until neutral. Alkali injuries are often worse than acid.
- Suspected open globe requires a shield, no pressure, avoidance of tonometry, and urgent surgical repair; give systemic antibiotics and tetanus prophylaxis.
- Traumatic hyphema is managed with rest, head elevation, and IOP monitoring; avoid aspirin and NSAIDs. Sickling must be excluded in Black patients.
- Retrobulbar haemorrhage causes proptosis, pain, and rising IOP; treat with lateral canthotomy and cantholysis if vision is threatened.
- Intraocular foreign body is confirmed by CT; MRI is avoided if metallic.
Worked example
A worker splashes alkaline drain cleaner into one eye. He has severe pain, redness, and corneal haze. Immediate management is prolonged irrigation with saline for at least 30 minutes, checking conjunctival pH until it is neutral. Topical anaesthetic allows irrigation but is not sent home. After irrigation, examine for limbal ischaemia and corneal opacity. Urgent ophthalmology review is arranged; severe burns may need amniotic membrane grafting and aggressive topical steroids under specialist care.
Traps that cost marks
Do not measure IOP or perform tonometry in a suspected open globe. Do not delay irrigation to complete history. In hyphema, missing sickle cell trait can lead to rebleeding and glaucoma. In orbital trauma, a relative afferent pupillary defect suggests optic nerve injury and needs urgent assessment.