Retrobulbar Haemorrhage

Bleeding into the retrobulbar space or orbit that raises orbital pressure, leading to compression of the optic nerve and ocular circulation; an ophthalmic emergency in which irreversible loss of vision may occur within 90 to 120 minutes.

• Causes: blunt orbital trauma, orbital fracture, eyelid or orbital surgery (blepharoplasty, sinus surgery, orbital decompression, retrobulbar and peribulbar anaesthesia), cataract surgery with a sharp needle block, spontaneous in anticoagulated patients or those with coagulopathy, orbital varix, vascular malformation, and tumour haemorrhage.
• Risk factors: warfarin, direct oral anticoagulants, antiplatelets, thrombocytopenia, hypertension, uncontrolled coughing, and Valsalva manoeuvre.
• Compression of the optic nerve and its vessels, central retinal artery occlusion and ischaemia of the nerve and retina follow; the mechanism is similar to a compartment syndrome.

• Severe orbital pain, rapid proptosis, tense swollen eyelids, subconjunctival haemorrhage and chemosis, restricted or absent ocular movements, increasing intraocular pressure, reduced vision, relative afferent pupillary defect, dilated pupil, nausea and vomiting, and headache.
• Fundus: retinal artery pulsation or occlusion, pale or oedematous disc, choroidal folds; very high intraocular pressure (above 40 mmHg).
• Features of orbital compartment syndrome: tense, hard "wooden" orbit that cannot be retropulsed.
• Delayed or subacute forms produce slower proptosis over hours to days.

• Clinical diagnosis. Do not delay treatment for imaging or visual field testing when vision is threatened.
• Rapid bedside assessment: acuity, pupils, motility, intraocular pressure (Tonopen, handheld), orbital tension, optic nerve function.
• CT orbits after emergency decompression (or before if the patient is stable and diagnosis uncertain and vision preserved): shows haematoma, tenting of the globe (posterior globe flattened with conical deformity), fractures and foreign bodies.
• Coagulation screen, platelets, full count, group and save; check anticoagulant doses and reverse where indicated.

• Lateral canthotomy and cantholysis immediately (at the bedside) for vision loss, relative afferent pupillary defect, intraocular pressure above 40 mmHg, tense proptosis, or retinal artery occlusion:
  • Anaesthetise the lateral canthus with 2 percent lidocaine with adrenaline (3 to 5 mL), clean with povidone iodine.
  • Crush the lateral canthus with a haemostat for 1 to 2 minutes (to reduce bleeding), then cut along the crush line (1 to 2 cm lateral canthotomy) to the orbital rim.
  • Strum the lower lateral canthal tendon (inferior cantholysis) with scissors directed inferiorly and posteriorly until the lid becomes loose; if the orbit remains tight, perform superior cantholysis.
  • Repeat the intraocular pressure and vision; aim for pressure below 30 mmHg and a soft orbit.
• Medical measures (adjunct, not a substitute): acetazolamide 500 mg IV, mannitol 20 percent 1 to 2 g/kg IV over 30 minutes, topical timolol 0.5 percent twice daily, head elevation 30 degrees, ice packs, analgesia, antiemetics (ondansetron 4 mg IV), tranexamic acid 1 g IV in trauma, and methylprednisolone 500 mg to 1 g IV in selected patients.
• If vision does not recover: surgical orbital decompression (removal of orbital floor or medial wall) with drainage of haematoma, performed by ophthalmology, oculoplastics or ENT.
• Reverse anticoagulation where possible (vitamin K 5 to 10 mg IV for warfarin, prothrombin complex concentrate 25 to 50 units/kg, idarucizumab 5 g for dabigatran, andexanet alfa for factor Xa inhibitors); stop antiplatelets if safe, correct platelets above 100 x 10^9/L.
• Admission with hourly observation of vision, pupils and pressure for 24 hours; antibiotics if surgery or open wound.
• Prognosis depends on the time to decompression; recovery is variable and may include optic atrophy; prompt action avoids permanent blindness.