Traumatic hyphema with sickle cell trait: a rebleed, a rising pressure and a drug to avoid
A 9-year-old boy is brought to eye casualty after being struck in the right eye by a cricket ball four hours earlier. Acuity is 6/12 OD and 6/6 OS. There is a 3 mm layered hyphema with no active bleeding, a small upper lid laceration, and no clinical evidence of globe rupture; the Seidel test is negative and intraocular pressure is 18 mmHg. He is otherwise healthy, but his mother mentions that he and his father carry sickle cell trait, and the newborn screening record confirms haemoglobin AS. He is given topical prednisolone acetate 1% four times daily and topical atropine 1% twice daily, and discharged with advice to rest at home and return in 48 hours.
He returns on day 3 with a rebleed: the hyphema now fills about 60% of the anterior chamber, acuity is 6/60, and intraocular pressure is 34 mmHg. He has mild nausea but no vomiting and no pain.
1. Critique the initial management and explain what the sickle cell trait adds to the risk assessment.
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Several choices were unsafe. In a child with haemoglobin AS, a hyphema is not a routine outpatient problem:
- Disposition – sickle cell trait markedly increases the risk of rebleed and of sight-threatening complications from even modest pressure rises. He should have been admitted (or observed in a day unit with guaranteed daily review), not sent home for 48 hours. Rebleeds characteristically occur on days 2–5, so the interval was chosen exactly when surveillance matters most.
- Activity restriction – strict rest with the head of the bed elevated about 30 degrees, no reading, no screens, no rough play, and avoidance of straining or nose-blowing should have been specified, plus an eye shield and avoidance of NSAIDs and aspirin.
- Antiemetics and analgesia – prophylactic antiemetic cover for nausea and paracetamol rather than NSAIDs would reduce the risk of Valsalva-induced rebleeding.
- Monitoring – daily acuity, slit lamp and intraocular pressure; a B-scan if the fundus cannot be seen; screening for associated injury such as retinal dialysis, commotio retinae and lens subluxation; gonioscopy once the chamber clears.
Why trait matters: sickle haemoglobin polymerises under hypoxia, acidosis, dehydration and hyperosmolarity, so the anterior segment can sickle locally even when the patient is systemically well. Trait is also associated with a higher rebleed rate. The classic dangerous consequence is anterior segment ischaemia and optic atrophy from relatively modest intraocular pressure elevation, so thresholds for intervention are lower than in other children.
2. How will you lower the intraocular pressure, and which agent is contraindicated? What would you do about the nausea?
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The aim is to keep intraocular pressure below roughly 21–25 mmHg, because in sickle haemoglobinopathy optic nerve damage and central retinal artery compromise can occur at pressures other children tolerate.
Use: topical beta-blocker (timolol 0.25–0.5% twice daily, watching for bronchospasm), topical alpha-2 agonist (brimonidine 0.15–0.2%, with awareness of drowsiness in a child), continuation of topical steroid to suppress trabeculitis, and a cycloplegic. If needed, intravenous mannitol can be used cautiously, but it causes haemoconcentration and hyperviscosity, so it is not first line and requires hydration.
Avoid acetazolamide and other carbonic anhydrase inhibitors. They produce a metabolic acidosis, which shifts the oxygen-haemoglobin dissociation curve and promotes sickling; in a patient with sickle haemoglobin this can precipitate anterior segment ischaemia and worse visual outcome. This is the single most examinable point in this scenario. Topical dorzolamide is generally avoided for the same reason.
Nausea must be treated actively with an antiemetic such as ondansetron (or metoclopramide), because retching raises episcleral venous pressure and intraocular pressure and can provoke a further rebleed. Also ensure generous oral or intravenous hydration, treat any pain, and correct acidosis if present. Arrange urgent haematology input and check haemoglobin, reticulocytes and haemoglobin electrophoresis if not already documented.
3. Medical treatment fails to bring the pressure below 30 mmHg after 24 hours. What are your surgical indications and the perioperative precautions specific to sickle haemoglobinopathy?
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Indications for anterior chamber washout in this child:
- Intraocular pressure persistently above about 25 mmHg for 24 hours despite maximal tolerated medical therapy in a patient with sickle haemoglobinopathy - this is the key lowered threshold.
- Early corneal blood staining.
- A total, dark, non-clearing hyphema.
- A rebleed with uncontrolled pressure or deteriorating vision.
Perioperative precautions:
- Admit and involve haematology and paediatric anaesthesia. Hydrate preoperatively; correct acidosis; keep the child warm; avoid hypoxia and hypotension; use pulse oximetry and avoid tourniquets or prolonged procedures.
- Preoperative simple or exchange transfusion may be advised (aiming for haemoglobin S below about 30%) in severe cases or if the child is symptomatic; this is a haematology decision, not an ophthalmic one.
- Avoid hypotensive anaesthesia and avoid sudden pressure changes. Use a cohesive viscoelastic to maintain the anterior chamber, irrigate gently with balanced salt solution, and avoid damaging the lens or iris.
- Evacuate the clot with irrigation and aspiration rather than vigorous expression; control any active bleeding; consider a small surgical iridectomy only if bleeding persists from the iris root.
- Postoperatively continue topical steroid and cycloplegia, monitor pressure daily, and maintain hydration and oxygenation. Watch for re-accumulation and for amblyopia risk in a child of this age once the eye has settled.