Ophthalmic Emergencies on Call: A Resident's Survival Guide

Last updated: October 2026

Your first night on call can feel overwhelming. The good news is that a small number of conditions cause most true ophthalmic emergencies. Recognise these early, start the right first steps, and call your senior. This guide is written for that moment.

Triage at a glance

1. Chemical injury

• Do first, ask later: start irrigation before taking a history or testing vision. Use topical anaesthetic and normal saline or Ringer's lactate, at least 1–2 litres.
• Evert both lids, double-evert the upper lid, and sweep the fornices to remove particles (lime and cement are common).
• Check the pH 5 minutes after stopping. Continue until it is neutral (around 7).
• Alkalis are worse than acids because they penetrate deeper. Grade limbal ischaemia (Roper-Hall / Dua) to predict prognosis. See our chemical injury page.

2. Orbital compartment syndrome (retrobulbar haemorrhage)

• Recognise: after trauma or orbital/lid surgery: pain, tense proptosis, a "rock-hard" orbit, raised IOP, restricted movements, falling vision and a new RAPD.
• This is a clinical diagnosis. Do not delay for a CT scan. Perform a lateral canthotomy with inferior cantholysis (see our step-by-step guide).
• Irreversible optic nerve damage may begin within about 90–120 minutes of ischaemia.

3. Central retinal artery occlusion

• Recognise: sudden painless profound loss of vision, a pale retina with a cherry-red spot, and "box-carring" of vessels. A cilioretinal artery may spare central vision.
• Treat it as a stroke: if onset is recent, arrange urgent stroke-pathway assessment (local protocol) for possible thrombolysis and cardiovascular work-up.
• Ocular massage, paracentesis and IOP-lowering have no proven benefit and must never delay stroke referral.
• In patients over 50, check ESR/CRP: arteritic CRAO (GCA) must not be missed.

4. Acute angle closure

• Recognise: pain, headache, nausea or vomiting, haloes, a mid-dilated fixed pupil, corneal oedema, shallow anterior chamber, and very high IOP. A patient vomiting with a red eye is angle closure until proven otherwise.
• Lower the IOP: acetazolamide 500 mg IV or orally (check for sulfa allergy and renal function), timolol 0.5%, an alpha-agonist, and topical steroid. Use IV mannitol (1–2 g/kg) if IOP remains very high.
• Pilocarpine 2% works only after IOP starts falling; an ischaemic iris sphincter will not respond earlier.
• Corneal indentation gonioscopy can help open the angle. Definitive treatment is laser iridotomy in both eyes (the fellow eye is at high risk), or lens extraction. See our angle closure page.

5. Open globe injury

• Suspect it with: a peaked pupil, shallow or deep anterior chamber, positive Seidel test, hyphaema, low IOP, 360° subconjunctival haemorrhage with chemosis, or a history of hammering metal-on-metal.
• Do: apply a rigid shield (no pad and no pressure), keep the patient nil by mouth, give analgesia and antiemetics, systemic antibiotics per local protocol, and update tetanus.
• Don't: measure IOP, put in drops or ointment, or remove a protruding foreign body.
• Get a CT of the orbits. No MRI until a metallic foreign body is excluded.

6. Acute post-operative endophthalmitis

• Recognise: within days to weeks of surgery or injection: pain, falling vision, hypopyon, vitritis, and loss of the red reflex.
• Do: vitreous tap and intravitreal antibiotics, typically vancomycin 1 mg/0.1 mL plus ceftazidime 2.25 mg/0.1 mL, according to your unit protocol.
• EVS rule: immediate vitrectomy if vision is light perception only. With hand movements or better, tap and inject is enough.

7. Giant cell arteritis

• Recognise: age over 50, headache, scalp tenderness, jaw claudication, polymyalgia symptoms, and transient or sudden visual loss. Look for a chalky-white swollen disc (AAION).
• Do: check ESR, CRP and platelets, and start high-dose steroids immediately. Do not wait for the biopsy. With visual loss, IV methylprednisolone is commonly used.
• Temporal artery biopsy remains useful within about 1–2 weeks of starting steroids. Coordinate with rheumatology. See our GCA page.

8. Orbital cellulitis

• Preseptal vs orbital: proptosis, painful or restricted eye movements, chemosis, reduced vision or a RAPD mean orbital involvement.
• Do: admit, start IV antibiotics, request a contrast CT of the orbits and sinuses, and refer to ENT. Monitor vision, colour vision and pupils regularly.
• A subperiosteal abscess or deteriorating optic nerve function needs surgical drainage. In diabetics with ketoacidosis or immunosuppression, think of mucormycosis.

9. Pupil-involving third nerve palsy

• A painful third nerve palsy with a dilated pupil is a posterior communicating artery aneurysm until proven otherwise.
• Arrange urgent same-day CT/MR angiography through emergency or neurosurgery. The "pupil-sparing" rule is not absolute, so image any doubtful or incomplete palsy. See our cranial nerve palsy page.

10. Macula-on retinal detachment

• When the macula is still attached, there is still central vision to save. Contact the vitreoretinal team urgently.
• Bullous superior detachments threaten the macula fastest. Position the patient to keep fluid away from the macula while awaiting surgery, and advise rest.

11. Bilateral optic disc swelling

• Measure blood pressure first: malignant hypertension is the diagnosis you can treat in the next hour.
• Then arrange same-day neuroimaging (MRI with MR venography, to exclude a mass and venous sinus thrombosis), followed by lumbar puncture with opening pressure if imaging is normal. See our papilloedema page.

Your call bag checklist

• Bright torch, direct ophthalmoscope, near vision card or phone acuity app
• 20D or 28D lens, a three-mirror or four-mirror gonioscope (if you have one), tonometer (Tono-Pen or iCare)
• Fluorescein strips, topical anaesthetic, dilating drops, pH strips
• Lid speculum, Desmarres retractor, sterile cotton buds for double eversion
• Rigid eye shields and a red pen for marking the eye before surgery

Drug doses and pathways differ between hospitals. Always follow your local protocol and involve your senior early.