section name header

Basics ⬇

Basics

Definition

Blood inside the anterior chamber in the form of a blood clot, settled blood in the ventral anterior chamber, or red blood cells suspended throughout the aqueous, giving a “cherry Kool-Aid” appearance to the aqueous.

Pathophysiology

  • Breakdown of the blood-aqueous barrier and/or direct injury to the iris and ciliary body blood vessels. Causes include direct tissue trauma to the cornea or anterior uvea (iris and ciliary body); prostaglandin release from tissue trauma or inflammatory mediators such as infectious agents; and direct damage to blood vessel walls, as with systemic hypertension, antigen-antibody complexes, or circulating infectious organisms or neoplastic cells.
  • Abnormal hemostasis due to a clotting deficiency or thrombocytopenia.
  • Bleeding from abnormal vessels within the eye. This is most commonly due to pre-iridal fibrovascular membranes (PIFMs), which form in response to chronic intraocular disease (uveitis, retinal detachment, glaucoma, neoplasia). Rarely, abnormal congenital blood vessels in the eye such as persistent pupillary membranes, tunica vasculosa lentis, or hyaloid artery may bleed, causing hyphema.

Systems Affected

Ophthalmic

Incidence/Prevalence

Not an uncommon ophthalmic finding and one that is important to recognize, as it may be the presenting clinical sign for a serious underlying systemic disease.

Signalment

Species

Dog and cat

Breed Predilections

Collies with collie eye anomaly

Signs

Historical Findings-Primary Ophthalmic Causes

  • Usually a unilateral presentation in an otherwise systemically normal patient.
  • Blunt globe trauma will often have a history of hit by a car, periocular dog bite, or exposure to cattle or horses.
  • Corneal perforation may have a history of a corneal ulcer with subsequent perforation; or preceding encounter with a cat resulting in a cat claw laceration, especially in puppies.

Historical Findings-Systemic Causes

  • Unilateral or bilateral presentation; bilateral presentation is strongly supportive of a systemic etiology.
  • Weight loss, anorexia, lethargy, and decreased vision or loss of vision may accompany some systemic causes.
  • Ocular pain usually accompanies infectious and neoplastic causes due to the accompanying uveitis.

Physical Examination Findings-Primary Ophthalmic Causes

  • Except in cases of generalized trauma (hit by car), the physical exam will be unremarkable with abnormalities restricted to the globe and periorbital soft tissues.
  • Blunt trauma will have painful periorbital soft tissue swelling and uncommonly orbital rim fractures; there is often total hyphema obscuring other intraocular structures.
  • Perforating trauma is associated with severe pain, a bloody or clear (aqueous) ocular discharge, varying degrees of hyphema, miosis, and anterior synechia, and a shallow anterior chamber; corneal edema will surround the perforation site and an iris prolapse may be present through the perforation.
  • Hyphema due to PIFMs, retinal detachment, neoplasia, or congenital vasculature are usually non-painful with very little intraocular inflammation (aqueous flare, miosis).
  • Hypermature cataract supports the development of either PIFM or retinal detachment as a cause of the hyphema.

Physical Examination Findings-Systemic Disease Causes

  • When an underlying systemic disease is suspected, a thorough physical exam is warranted; depending on the systemic disease the physical exam may be unremarkable or have significant findings such as lymphadenopathy.
  • Ophthalmic examination findings will vary depending on the etiology of the hyphema.
  • Non-inflammatory etiologies such as hypertension, thrombocytopenia, and clotting disorders will usually have minimal discomfort and uveitis (trace or no aqueous flare, no miosis, no conjunctival hyperemia). Hypertension is almost always associated with retinal involvement such as retinal hemorrhages and/or retinal detachment.
  • Clotting deficiencies may have bleeding elsewhere, including the subconjunctival tissue and retrobulbar space; thrombocytopenia may have petechia on the palpebral or nictitans conjunctiva. Infectious and neoplastic etiologies will often have significant pain, anterior uveitis (miosis, aqueous flare, fibrin, iridal hyperemia and swelling), chorioretinitis with retinal detachment, and possible secondary glaucoma.

Causes

See Table 1.

Risk Factors

  • Ophthalmic: hypermature cataract, retinal detachment, chronic anterior uveitis.
  • Systemic: any disease, disorder, or geographic location predisposing to the systemic diseases known to cause uveitis or direct vascular damage (e.g., chronic renal disease or hyperthyroidism predisposing to systemic hypertension).

Diagnosis ⬆ ⬇

Diagnosis

Differential Diagnosis

Deep corneal vascularization, along the ventral limbus, can be mistaken for hyphema.

CBC/Biochemistry/Urinalysis

Abnormal findings may help support a systemic disease.

Other Laboratory Tests

Based on history and physical examination findings, clotting profile and serology (rickettsial, fungal) may be indicated if systemic disease is suspected.

Imaging

  • Ocular ultrasound is indicated to evaluate for retinal detachment or uveal tumors when not visible on the ophthalmic examination.
  • Based on history and physical examination findings, thoracic radiographs, abdominal radiographs, and abdominal ultrasound may be indicated if systemic disease is suspected.

Diagnostic Procedures

  • Doppler blood pressure measurement if hypertension is suspected.
  • Lymph node aspirates if lymphadenopathy is present or if neoplasia or fungal disease is suspected.

Pathologic Findings

Gross hemorrhage in the anterior chamber.

Treatment ⬆ ⬇

Treatment

Appropriate Health Care

Outpatient medical care is appropriate unless an underlying systemic disease is identified that requires hospitalization.

Activity

No restricted activity is required unless the patient is blind (restrict environment to fenced yards, no in-ground pools, leash walks, etc.) or the hyphema is due to thrombocytopenia or clotting disorder (avoid rough play, unrestricted running, etc.).

Client Education

  • Hyphema itself, although it appears dramatic, is not painful.
  • It is very important to identify the underlying cause of the hyphema, as some etiologies pose a serious health threat.
  • Ophthalmic treatment is important to initiate immediately to try to prevent painful and sometimes irreversible and blinding sequela like glaucoma.

Surgical Considerations

  • Hyphema secondary to a perforating corneal laceration or ulceration should be surgically repaired by direct suturing of the cornea (laceration) or corneal graft (perforated ulcer) when a visual outcome is expected. For a severe perforation with extensive iris prolapse and loss of the pupil, enucleation is recommended.
  • Permanently blind and painful eyes should be enucleated (with histopathology) for permanent comfort.
  • Surgical irrigation/removal of the hyphema is not successful, as the trauma of the surgery results in exacerbation of the hyphema and intraocular inflammation.

Medications ⬆ ⬇

Medications

Drug(s) Of Choice

  • Topical prednisolone acetate 1% or dexamethasone 0.1% q4–8h to help stabilize the blood-aqueous barrier; do not use if a corneal ulcer or perforation is present.
  • Atropine 1% q6–24h to help prevent posterior synechia; atropine is contraindicated if secondary glaucoma is present.
  • Systemic NSAID (carprofen, meloxicam, deracoxib) with perforating trauma for analgesia and to help stabilize the blood-aqueous barrier.
  • Systemic prednisone/prednisolone with known or suspected choroidal/retinal involvement, depending on the underlying cause; anti-inflammatory dose (0.5–1.0 mg/kg PO q24h) can be used for blunt trauma, FIP, and rickettsial and fungal disease with proper antimicrobial therapy.
  • Topical carbonic anhydrase inhibitors (dorzolamide 2%, brinzolamide 1%) q8h, beta-blocker (timolol 0.5%) q8–12h, and/or sympathomimetic (dipivefrin 0.1%) q8–12h can be used if secondary glaucoma is present.

Contraindications

  • Topical NSAIDs (e.g., flurbiprofen, diclofenac, ketorolac,) are generally considered contraindicated with hyphema.
  • Topical prostaglandin analogues (latanoprost, travoprost, bimatoprost) are contraindicated in secondary glaucomas.

Follow-Up ⬆ ⬇

Follow-Up

Patient Monitoring

  • Tonometry should be used to monitor for secondary glaucoma, which lowers the prognosis for a visual outcome.
  • Perform tonometry every 1–2 days if the IOP is high normal or greater, or if risk factors such as fibrin and/or posterior synechia are present.
  • Perform tonometry weekly if the IOP is low, or if the hyphema and anterior uveitis are mild-moderate in severity.
  • Tonometry is contraindicated with a corneal perforation.

Possible Complications

Secondary glaucoma, posterior synechia/dyscoria, cataract formation, loss of vision, possible loss of the eye if the eye becomes permanently blind and painful.

Expected Course and Prognosis

  • If the underlying cause of the hyphema can be successfully treated, such as repair of a corneal laceration or control of hypertension, and intraocular damage is not extensive, the prognosis is good for complete resolution of the hyphema.
  • If trauma to the eye is severe or if the underlying disease is not controlled, the hyphema will persist and blindness can result; no improvement in hyphema after 2 weeks following blunt trauma has a poor prognosis for return of vision.
  • Hyphema caused by bleeding from PIFMs usually does not resolve or will resolve and recur.
  • If the eye is painful due to a perforated globe or secondary glaucoma, with no reasonable hope of regaining vision, enucleation is recommended.

Miscellaneous ⬆

Miscellaneous

Abbreviations

  • CEA = collie eye anomaly
  • FIP = feline infectious peritonitis
  • IOP = intraocular pressure
  • NSAID = nonsteroidal anti-inflammatory drug
  • PIFM = pre-iridal fibrovascular membrane

Author Margi A. Gilmour

Consulting Editor Paul E. Miller