Hyphema

Hyphema is defined as the accumulation of red blood cells (RBCs) in the anterior chamber, between the posterior surface of the corneal endothelium and the anterior surface of the iris. It most commonly results from traumatic disruption of the delicate vasculature of the iris stroma and ciliary body, producing haemorrhage that layers inferiorly under gravity.

The condition is graded 0–IV according to the proportion of anterior chamber volume occupied by blood. The primary determinant of short-term prognosis is re-bleed — spontaneous recurrent haemorrhage occurring most commonly on days 2–5 as the initial fibrin clot retracts before complete vascular healing. Re-bleed is associated with a 5–10-fold increase in complications including corneal blood staining, IOP elevation, and optic atrophy.

Sickle cell trait and disease represent the most critical systemic modifier of hyphema management. The anterior chamber environment — hypoxic, acidic, and hyperosmolar — promotes sickling of haemoglobin S-containing erythrocytes, producing vascular occlusion and severe IOP spikes at IOP levels that would not threaten the optic nerve in non-sickle cell patients. This fundamentally alters the therapeutic thresholds and treatment choices.

Long-term, angle recession accompanying traumatic hyphema predisposes to secondary open-angle glaucoma that may manifest years to decades after the original injury, requiring lifelong IOP surveillance.

Traumatic (~90% of cases):

• Blunt ocular trauma (ball sports, assault, airbag deployment, rubber projectiles) — disruption of iris/ciliary body vasculature by the hydraulic shockwave
• Penetrating trauma — direct vascular laceration
• Intraocular surgery — inadvertent vessel disruption (post-cataract surgery, post-glaucoma surgery, post-vitrectomy)

Spontaneous (~10% of cases):

• Iris neovascularisation (rubeosis iridis): Proliferative diabetic retinopathy, central/branch retinal vein occlusion, ocular ischaemic syndrome — fragile new vessels bleed spontaneously
• Anticoagulation / antiplatelet therapy: Warfarin, DOACs (apixaban, rivaroxaban), aspirin, clopidogrel — bleed risk for minor iris trauma that would otherwise be self-limiting
• Bleeding diatheses: Haemophilia A and B, von Willebrand disease, thrombocytopenia, leukaemia, disseminated intravascular coagulation (DIC)
• Iris/ciliary body tumours: Iris melanoma, ciliary body melanoma — vascular tumour erosion; iris metastasis
• Juvenile xanthogranuloma (JXG): The classic cause of spontaneous hyphema in children — xanthogranulomatous nodules on the iris with highly vascular stroma bleed without trauma; systemic skin nodules may be present
• Fuchs heterochromic iridocyclitis: Spontaneous microhyphema from friable neovascularisation at angle; typically occurs at slit-lamp contact lens examination (Amsler sign)

Blunt ocular trauma generates a rapid anteroposterior compressive force followed by equatorial globe expansion. The resulting hydraulic shockwave through the anterior chamber produces centrifugal forces that tear the blood vessels of the iris stroma and ciliary body vasculature — the major vascular supply derived from the long and short posterior ciliary arteries forming the major arterial circle of the iris.

Released red blood cells layer inferiorly by gravity, producing the characteristic meniscus visible at the slit-lamp. A fibrin clot forms within 12–24 hours, stabilising the initial haemorrhage. However, clot retraction occurring between days 2 and 5 — as fibrinolysis begins — exposes the damaged vessel lumen before complete healing. This window of vulnerability defines the re-bleed period. Re-bleed is typically larger than the primary haemorrhage and carries significantly higher complication rates.

IOP elevation occurs through several mechanisms: physical obstruction of the trabecular meshwork by RBCs and fibrin debris; haemolytic glaucoma (RBC ghosts from lysed erythrocytes obstruct the trabecular meshwork); and ghost cell glaucoma (denatured, rigid khaki-coloured erythrocytes that have lost their normal deformability traverse from the vitreous through a disrupted zonule/posterior capsule). Sustained elevated IOP leads to corneal endothelial dysfunction, allowing haemoglobin degradation products (haemosiderin) to permeate the corneal stroma — producing corneal blood staining.

In sickle cell haemoglobinopathy, the unique microenvironment of the anterior chamber (hypoxia from high metabolic activity, low pH from lactate accumulation, and relative hyperosmolarity) causes polymerisation of deoxygenated HbS, producing the rigid sickle-shaped erythrocytes that occlude capillaries, impair aqueous drainage, and produce severe IOP elevation at levels (≥24 mmHg) that critically reduce blood flow to an already compromised optic nerve head.

• Sports participation: Squash, racquetball, cricket, baseball, and martial arts carry the highest risk of blunt ocular trauma; inadequate or absent protective eyewear is the most modifiable risk factor.
• Assault and violence: Fist injuries and household/workplace assaults.
• Male sex and younger age: Males account for approximately 75–80% of traumatic hyphema cases; young adults and children are disproportionately affected.
• Anticoagulation and antiplatelet therapy: Warfarin, direct oral anticoagulants, aspirin, and clopidogrel significantly increase re-bleed risk and the severity of spontaneous hyphema.
• Haemophilia and bleeding disorders: Increased tendency to re-bleed and poor clot formation.
• Sickle cell trait or disease: African, Mediterranean, and Middle Eastern descent; HbAS, HbSS, or HbSC genotype; dramatically alters management thresholds and prognosis.
• Prior hyphema: Previous ocular trauma may predispose to recurrent bleeding from scarred or abnormal iris vasculature.
• Rubeosis iridis: Diabetic patients, those with CRVO or ocular ischaemic syndrome — neovascular vessels bleed spontaneously.

Visible blood level: The hallmark — a horizontal meniscus of blood in the inferior anterior chamber, layering by gravity. In microhyphema, RBCs are only visible as circulating cells on slit-lamp examination without a discrete fluid level.

Red/pink anterior chamber: Even microhyphema imparts a pink tinge to the aqueous visible on slit-lamp; the whole AC may appear uniformly red in higher grades.

Elevated IOP: From trabecular obstruction by RBCs and debris. May be markedly elevated in sickle cell patients even with small hyphema.

Concurrent iris injuries: Sphincter tears (radial notches at pupil margin), iridodialysis (peripheral iris disinsertion), and iris transillumination defects are commonly present alongside hyphema from the same traumatic event.

Corneal blood staining (late): Yellow-brown discolouration of corneal stroma beginning centrally and spreading; occurs with sustained elevated IOP (>25 mmHg for ≥6 days, or >35 mmHg for ≥2–3 days) or compromised endothelium. Represents haemosiderin deposition in corneal stroma and is potentially irreversible.

Clot evolution: Fresh blood (bright red) → dark red clot (24–48 hours) → yellow-brown discolouration as RBCs lyse (days 5–7); re-bleed produces fresh bright red blood on top of dissolving old clot.

• Decreased vision: Proportional to grade — microhyphema may cause minimal blur; grade III–IV produces markedly reduced or absent functional vision through the involved area.
• Pain: From the initiating trauma; secondary pain from elevated IOP (throbbing, periorbital pressure); ciliary spasm.
• Photophobia: From ciliary spasm and iris inflammation; proportional to severity.
• Redness: Conjunctival injection may accompany significant anterior segment trauma.
• Awareness of floating blood: Some patients report seeing a dark curtain moving across their vision with eye movement — the mobile blood level shifting.

• Re-bleed (most feared acute complication): Occurs in 4–35% of cases; peak days 2–5; produces a larger haemorrhage than the primary bleed, with dramatically higher rates of IOP elevation, corneal staining, and optic atrophy. In sickle cell patients, even small re-bleeds can cause catastrophic IOP spikes.
• IOP elevation: Acute: from trabecular obstruction by RBCs; managed medically. Chronic: angle recession glaucoma (can develop years later); requires lifelong monitoring.
• Corneal blood staining: Irreversible yellowing of the corneal stroma from haemosiderin deposition; most frequent with total hyphema and sustained high IOP or compromised corneal endothelium. Treatment is surgical (penetrating keratoplasty) once established.
• Optic atrophy: From sustained elevated IOP, especially in sickle cell patients where IOP threshold for optic ischaemia is significantly lower than in non-sickle cell patients.
• Sickle cell crisis in the anterior chamber: Sickling of HbS erythrocytes in the hypoxic, acidic AC microenvironment produces vascular occlusion, IOP spikes, and anterior segment ischaemia; potentially causes irreversible optic nerve damage at IOP levels of 24–30 mmHg.
• Peripheral anterior synechiae (PAS): Organisation of blood clot against the angle produces synechial angle closure contributing to chronic secondary glaucoma.
• Amblyopia: In children with persistent hyphema obscuring the visual axis; requires early intervention to prevent deprivation amblyopia.

• Sickle cell disease and trait (CRITICAL): Patients with HbSS (sickle cell disease), HbSC disease, or HbAS (sickle cell trait) are at dramatically increased risk of complications. The hypoxic, acidic, hyperosmolar environment of the anterior chamber causes sickling of HbS erythrocytes, producing capillary occlusion and IOP spikes. Management is significantly modified: IOP threshold for surgical intervention is lowered to 24 mmHg; oral acetazolamide and topical CAIs must be AVOIDED (systemic acidosis worsens sickling); hyperosmotic agents are also risky. Screen all patients of African, Mediterranean, or Middle Eastern descent with haemoglobin electrophoresis.
• Haemophilia A and B: Factor VIII and IX deficiencies respectively; prolonged bleeding time; haematology co-management required; factor replacement may be needed before surgical intervention. Spontaneous re-bleed risk very high.
• Von Willebrand disease: Most common inherited bleeding disorder; prolonged bleeding time; desmopressin (DDAVP) can be used to increase vWF levels acutely.
• Anticoagulation therapy: Warfarin, apixaban, rivaroxaban, dabigatran — discuss cessation/dose adjustment with the prescribing physician, balancing thromboembolic risk. Aspirin and clopidogrel should be stopped unless there is a mandatory cardiac indication.
• Juvenile xanthogranuloma (JXG): Spontaneous hyphema in a child without trauma should raise suspicion for JXG. Examine the skin for yellowish-tan xanthogranulomatous nodules. Treatment is with topical and systemic corticosteroids or low-dose radiotherapy.
• Child non-accidental injury: Traumatic hyphema with bilateral retinal haemorrhages in a child without an adequate accidental mechanism may indicate non-accidental injury (shaken baby syndrome). Immediate paediatric safeguarding referral.

Slit-lamp examination: Grade blood level (measure height in mm or as proportion of AC), assess corneal endothelium for staining, examine iris for concurrent damage (sphincter tears, iridodialysis, TIDs), assess AC depth and clarity above the blood level, and check for hypopyon (white cells — suggests concurrent uveitis or endophthalmitis).

IOP measurement: Goldmann applanation if cornea is clear and intact. Use iCare rebound tonometry if there is any concern about corneal integrity or wound. Document baseline IOP and monitor daily during the first 7–10 days (re-bleed risk period).

Gonioscopy: Deferred until blood clears sufficiently (risk of mechanically inducing re-bleed with contact lens); essential at follow-up to assess angle recession and peripheral anterior synechiae.

B-scan ultrasound: Mandatory if grade III–IV hyphema prevents adequate fundal view; excludes vitreous haemorrhage, retinal detachment, and posterior segment injury.

CT orbit and head: If penetrating injury is suspected, IOFB cannot be excluded, bony fracture is queried, or non-accidental injury in children. MRI is contraindicated until metallic IOFB is excluded.

Sickle cell screen: Haemoglobin electrophoresis in all patients of African, Mediterranean, or Middle Eastern descent with hyphema — regardless of known sickle cell status. Sickle cell trait (HbAS) is common and often undiagnosed.

Full blood count and coagulation screen: In spontaneous hyphema or where bleeding disorder is suspected; includes platelets, PT, APTT, and fibrinogen.

Dilated fundus examination: When hyphema has cleared sufficiently to permit an adequate view; assess for concurrent retinal injury, choroidal rupture, and angle recession effects.

Grade I–II traumatic hyphema without re-bleed carries an excellent prognosis — most cases resolve spontaneously within 5–7 days with conservative management, and final visual acuity is typically preserved if no concurrent posterior segment injury is present.

Re-bleed significantly worsens prognosis — in eyes with primary re-bleed, the rates of IOP elevation, corneal staining, and optic atrophy are substantially higher. Grade III–IV hyphema has a more prolonged resolution and higher complication rate; approximately 25–35% of total hyphemas develop IOP elevation requiring intervention.

Sickle cell patients represent the highest-risk group — even small hyphemas (grade I) can produce optic nerve damage due to the lower IOP threshold for ischaemia. These patients require immediate admission and close monitoring. With prompt surgical washout when thresholds are met, permanent visual loss can usually be prevented.

The development of corneal blood staining represents a permanent complication requiring eventual penetrating keratoplasty. Long-term, angle recession glaucoma (developing in 5–10% of eyes with significant angle recession over many years) remains a lifelong risk that can be adequately managed with IOP-lowering therapy and surgical intervention when required.

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