Key Facts

Eye emergencies range from immediately sight-threatening conditions requiring emergency treatment (chemical injury, CRAO, AACG) to common presentations that need appropriate assessment and referral. Accurate visual acuity measurement is essential.

Epidemiology

Eye complaints account for approximately 6% of all ED attendances. Corneal abrasions/foreign bodies are the most common presentation. Chemical eye injuries account for ~7% of eye injuries. Acute angle-closure glaucoma has an incidence of approximately 12 per 100,000 per year.

Aetiology

• Trauma: Corneal abrasion, foreign body, blunt injury (hyphaema, globe rupture), penetrating injury
• Infective: Conjunctivitis, keratitis, orbital cellulitis, endophthalmitis
• Vascular: CRAO, CRVO, giant cell arteritis
• Pressure: Acute angle-closure glaucoma
• Retinal: Retinal detachment, vitreous haemorrhage
• Chemical: Alkali (worse) and acid burns

Pathophysiology

Vision-threatening emergencies involve either direct structural damage (penetrating injury, chemical burn), vascular occlusion (CRAO — retinal ischaemia within minutes), or raised intraocular pressure (AACG — aqueous humour outflow blocked by iris).

Chemical Eye Injury

• Severe pain, blepharospasm, tearing, reduced VA
• Alkali: Penetrates deeply (liquefactive necrosis) — worse prognosis
• Acid: Coagulative necrosis — tends to self-limit
• Irrigate BEFORE assessment

Acute Angle-Closure Glaucoma

• Severe eye pain, headache, nausea/vomiting
• Red eye, hazy cornea (oedema)
• Fixed, mid-dilated pupil; rock-hard eye on palpation
• IOP >40 mmHg (normal 10-21)

Central Retinal Artery Occlusion

• Sudden, painless, complete visual loss
• RAPD (relative afferent pupillary defect)
• Cherry-red spot at macula on fundoscopy
• Pale, oedematous retina

Red Flags

• Sudden painless visual loss — CRAO, CRVO, retinal detachment, vitreous haemorrhage, GCA
• Chemical injury — irrigate immediately
• Penetrating injury — do NOT remove foreign body
• Painful red eye with reduced VA — AACG, keratitis, iritis, endophthalmitis
• New temporal headache with jaw claudication — GCA (ESR, temporal artery biopsy)

Bedside

• Visual acuity: Snellen chart — MUST document for all eye presentations
• Pupil assessment: RAPD (swinging torch test), size, shape, reactivity
• Slit lamp examination: Corneal assessment, anterior chamber (cells, flare, hyphaema)
• Fluorescein staining: Corneal epithelial defects (abrasion, ulcer, dendritic ulcer)
• IOP measurement: Tonometry — elevated in AACG
• Fundoscopy: Disc, macula, vessels, retina
• pH testing: Post-irrigation for chemical burns — target pH 7.0-7.4

Bloods

• ESR and CRP: If GCA suspected (ESR >50, CRP elevated)
• FBC: WCC if infection suspected

Imaging

• CT orbits: Orbital cellulitis, intraorbital foreign body, globe rupture, orbital fracture
• B-scan USS: If fundus not visible (vitreous haemorrhage) — assess retinal detachment
• CT head: If CRAO — assess for stroke

Special Tests

• Temporal artery biopsy: GCA — but do NOT delay steroid treatment for biopsy
• MRI orbits: Orbital apex syndrome, optic neuritis

Chemical Injury

• Immediate irrigation: 0.9% NaCl or water, minimum 30 minutes; check pH every 15 min; continue until pH 7.0-7.4
• Remove particulate matter: Evert eyelids, sweep fornices
• Emergency ophthalmology referral after irrigation

Acute Angle-Closure Glaucoma

• Pilocarpine 2% eye drops (constricts pupil, opens drainage angle)
• Timolol 0.5% eye drops (reduces aqueous production)
• Acetazolamide 500mg IV (reduces aqueous production)
• Analgesia and antiemetics: IV morphine, ondansetron
• Definitive: Laser peripheral iridotomy (both eyes)

Central Retinal Artery Occlusion

• Stroke-equivalent emergency: Consider thrombolysis within 4.5h (some centres)
• Ocular massage: May dislodge embolus
• Acetazolamide 500mg IV: Reduce IOP
• Refer to stroke pathway: Same risk factors and workup as TIA/stroke

Penetrating Eye Injury

• Shield eye with rigid shield (do NOT apply pressure)
• Nil by mouth, antiemetics (IV ondansetron)
• IV antibiotics: Co-amoxiclav 1.2g IV
• Tetanus prophylaxis
• Emergency ophthalmology for surgical repair

Pharmacological

• Chloramphenicol 0.5% drops: Corneal abrasion, bacterial conjunctivitis
• Cyclopentolate 1%: For iritis/uveitis (mydriatic + cycloplegic for pain relief)
• Topical steroids: ONLY under ophthalmology guidance (contraindicated in herpes simplex keratitis)
• GCA: Prednisolone 60-80mg PO immediately (or IV methylprednisolone 1g if visual symptoms)

Referral Criteria

• Chemical burn, penetrating injury, AACG, CRAO — emergency ophthalmology
• Retinal detachment, orbital cellulitis — same-day ophthalmology
• Corneal ulcer, hyphaema, severe uveitis — urgent ophthalmology (within 24h)
• GCA — rheumatology + ophthalmology; start steroids BEFORE biopsy

• Chemical burn: Depends on severity; alkali burns carry worse prognosis; Grade IV (Roper-Hall) — very poor visual outcome
• AACG: Good if treated promptly; untreated → permanent optic nerve damage
• CRAO: Poor visual prognosis overall; ~10% have cilioretinal artery sparing; fibrinolysis may help if within 4.5h
• Retinal detachment: >90% anatomical success with surgery; visual outcome depends on macula involvement
• GCA: High risk of bilateral visual loss if untreated; steroids prevent contralateral eye involvement

Roper-Hall Classification (Chemical Burns)

Red Eye — Key Differentials