Hifema

01Pathophysiology

Hyphema occurs when blunt force is transmitted to the globe, causing rapid anteroposterior compression and equatorial expansion of the eye. This shearing force tears the iris root, the ciliary body, or the major arterial circle of the iris, releasing blood into the anterior chamber. Because the anterior chamber is a closed, gravity-dependent space, red blood cells settle inferiorly, producing the classic visible layering when the patient sits upright.

The clinical danger comes not from the initial bleed but from its consequences. Erythrocytes and fibrin clog the trabecular meshwork, the drainage pathway for aqueous humor. This obstruction raises intraocular pressure (IOP), which can compromise optic nerve perfusion and lead to permanent vision loss if sustained. Prolonged contact between blood and the corneal endothelium produces corneal blood staining, a permanent rust-colored discoloration that mimics a leukoma and is one of the firmest indications for surgical evacuation.

The most feared complication is rebleeding, which classically peaks between days 2 and 5 after the initial injury. Rebleeds tend to be larger than the original hemorrhage and carry a worse visual prognosis. The mechanism involves clot retraction and lysis at the original bleeding site, exposing the damaged vessel before it has time to fully heal.

In sickle cell disease or trait, the pathophysiology takes a dangerous turn. The aqueous humor is hypoxic and acidic, conditions that promote sickling of erythrocytes. Sickled cells are rigid and cannot pass through the trabecular meshwork, so even a small hyphema can produce dramatic IOP elevation. This is the single most tested association in hyphema vignettes, and it changes the entire treatment algorithm.

02Classification

Higher grades correlate with worse visual outcomes and higher rates of complications, but even small hyphemas in sickle cell patients can be sight-threatening.

03Diagnostic Workup

The workup begins at the bedside. Before anything else, the examiner must rule out globe rupture, because applying pressure or instilling drops in a ruptured globe causes catastrophic extrusion of intraocular contents. Red flags include a peaked or teardrop pupil, a positive Seidel sign (fluorescein streaming away from a corneal defect under cobalt blue light), severe chemosis, and deep or shallow anterior chamber asymmetry. If globe rupture is suspected, place a rigid shield, obtain a CT, and consult ophthalmology immediately.

The best initial test for hyphema itself is the slit-lamp examination, which confirms layered red blood cells in the anterior chamber and quantifies the grade. Visual acuity and IOP measurement follow immediately. Tonometry is the most important physiologic measurement because IOP determines the urgency of treatment and the threshold for surgery.

In any patient of African, Mediterranean, Middle Eastern, or Indian descent, or in any patient with unknown sickle status, sickle screening is mandatory before treatment is finalized. This single step is one of the most tested decision points in hyphema cases.

When the hyphema is dense enough to obscure the fundus, B-scan ultrasonography evaluates the posterior segment for retinal detachment, vitreous hemorrhage, or a ruptured posterior globe. CT is reserved for suspected fracture, intraocular foreign body, or globe rupture.

04Management & Treatment

The first move in management is protection and stabilization. Place a rigid eye shield (never a pressure patch), elevate the head of the bed to 30 to 45 degrees, and restrict activity. Elevation lets blood settle inferiorly so the visual axis clears and the trabecular meshwork superiorly is partially spared. Patients are typically managed as outpatients with daily follow-up, but admission is reasonable for non-compliant patients, children, sickle cell patients, total hyphema, and high IOP.

Topical therapy has three components:

• A cycloplegic agent (atropine 1% two to three times daily, or cyclopentolate 1% three times daily) relieves ciliary spasm, reduces photophobia, and prevents posterior synechiae by keeping the iris mobile.

• A topical corticosteroid (prednisolone acetate 1% four to eight times daily) reduces inflammation and may reduce rebleeding rates.

• If the IOP is elevated above 24 mmHg, start a beta blocker (timolol 0.5% twice daily) and add an alpha agonist (brimonidine) or topical carbonic anhydrase inhibitor (dorzolamide) as needed.

Aspirin and NSAIDs are contraindicated because they inhibit platelet aggregation and increase rebleeding risk. This is a frequent test point.

Sickle cell patients require a modified algorithm. Acetazolamide is avoided because it lowers aqueous pH and promotes intraocular sickling, paradoxically raising IOP. Mannitol is also problematic because it causes hemoconcentration and dehydration, worsening sickling. The threshold for surgical intervention is much lower in these patients: IOP greater than 24 mmHg for more than 24 hours is generally accepted as an indication for washout in sickle patients, compared to the much higher thresholds used in non-sickle patients.

Antifibrinolytic therapy with oral aminocaproic acid (50 mg/kg every 4 hours, maximum 30 g/day, for 5 days) or tranexamic acid stabilizes the clot at the bleeding site and reduces rebleeding. Its use varies by institution and is not universal.

Surgical anterior chamber washout is the next best step when medical management fails. Indications include:

• IOP greater than 50 mmHg for 5 days, or greater than 35 mmHg for 7 days (non-sickle patients)

• IOP greater than 24 mmHg for more than 24 hours in sickle cell patients

• Total ("eight-ball") hyphema persisting beyond 5 days

• Early corneal blood staining (any duration)

• Failure of the hyphema to clear within 9 days, raising concern for peripheral anterior synechiae

The "next best step" logic on a vignette typically follows this hierarchy: rule out globe rupture first, then shield and elevate, then start topical cycloplegic and steroid, then add IOP control, then escalate to washout if criteria are met.

Long-term follow-up includes gonioscopy at 4 to 6 weeks to evaluate for angle recession, which can cause delayed-onset glaucoma even years later. All patients should be counseled on lifelong eye protection, especially during sports.

05Differential Diagnosis & Distractors

06Traps & High-Yield Pearls

The single biggest trap in hyphema vignettes is failing to screen for sickle cell disease or trait before choosing treatment. A vignette describing a young Black male with a basketball injury and a small hyphema is rarely about the hyphema itself; it is testing whether you will recognize the need for sickle screening and the contraindication to acetazolamide and mannitol. Choosing acetazolamide in a sickle patient is one of the fastest ways to lose a question.

The second classic trap is timing of rebleeding. Vignettes describing a patient who returns on day 3 to 5 with worsening vision and a larger hyphema are testing recognition of the rebleed window. This is also why aspirin and NSAIDs are forbidden, and why activity restriction matters even in mild cases.

A third trap is mistaking hypopyon for hyphema. Both layer in the anterior chamber, but hypopyon is white or yellow (pus) and signals infection or inflammation, while hyphema is red (blood) and signals trauma or vascular disease. Read the color descriptor in the vignette carefully.

A fourth trap is applying a pressure patch to a possible globe rupture. Any vignette with a peaked pupil, positive Seidel sign, or 360-degree subconjunctival hemorrhage demands a rigid shield and emergent surgical referral, not eye drops.

Finally, do not forget delayed angle-recession glaucoma. A patient with a remote history of blunt eye trauma who now presents with gradual unilateral vision loss and elevated IOP years later is being tested on the long-term sequela of hyphema.

The core competency being tested is recognizing hyphema as a stratified emergency: identify the grade, rule out globe rupture, screen for sickle cell, control IOP, prevent rebleeding, and know the surgical thresholds. Mastering the sickle cell modification and the rebleeding window will resolve the majority of hyphema questions you will encounter.