Continuing Education Activity

Hyphema is the accumulation of red blood cells (RBCs) in the anterior chamber of the eye. By definition, blood must be grossly visible, either on direct inspection or via slit-lamp examination. Blood accumulates from the disruption of the vessels of the iris or ciliary body, usually due to trauma or underlying medical conditions. This activity describes the pathophysiology, evaluation, and management of hyphema and highlights the role of the interprofessional team in caring for affected patients.

Objectives:

• Outline the causes of hyphema.
• Describe the presentation of a patient with hyphema.
• Review the complications of hyphema.
• Explain the importance of improving care coordination amongst the interprofessional team to enhance the management of patients with hyphema.

Introduction

Hyphema is defined as accumulated red blood cells (RBC) in the anterior chamber of the eye.[1] Blood must be grossly visible, either on direct inspection or slit-lamp examination. Blood accumulates from disruption of the vessels of the iris or ciliary body, usually due to trauma or underlying medical conditions. The anterior chamber is the area bounded by the cornea anteriorly, the angle laterally, and the lens and iris posteriorly. This space normally contains clear, aqueous humor, which is produced by the ciliary body and drained through the Canal of Schlemm. The angle, an important anatomic location, is where the trabecular network and the Canal of Schlemm are located. Blockage of this location inhibits aqueous drainage leading to an increase in intraocular pressure.[1][2]

Etiology

Blunt eye trauma is the most common cause of hyphema, although penetrating trauma and spontaneous hyphemas can occur as well.[2] Certain medical conditions put patients at risk of developing a hyphema such as leukemia, hemophilia, von Willebrand disease, sickle cell disease, and the use of anticoagulant medications. Neovascularization of the eye, often associated with diabetes mellitus, additionally puts patients at risk.

Moreover, post-surgical patients may develop hyphema intraoperatively, however, development can be delayed up to a week postoperatively.

Epidemiology

The incidence of traumatic hyphema is 12 out of 100 000, with 70% occurring in children.[3] It is most commonly seen in males 10 to 20 years old and usually occurs from sport or recreational injuries. Children are typically injured through ball-related sports such as baseball, basketball, softball, and soccer when the ball strikes the anterior surface of the globe.[4] Adolescents and adults are more likely to be injured via a high-energy blow to the eye, most commonly assault. Other etiologies include paintball guns, airsoft guns, and airbag deployment.[5]

Pathophysiology

Blunt or penetrating trauma causes traumatic hyphemas to the orbit. Tears in the vessels of the ciliary body and iris result in bleeding. Blunt forces applied to the anterior globe create an instantaneous increase in intraocular pressure, producing a shearing force across the ciliary body and iris.[2] Penetrating trauma produces a direct injury to the iris.

Spontaneous hyphemas often occur in patients whose medical conditions predispose them to ischemia, neovascularization, or vascular abnormalities. These patients will typically have a spontaneous vessel leak. As expected, it is more common in patients with diabetes, eye tumors, clotting disorders, sickle cell, and those on anticoagulants.[6][7]

History and Physical

Most patients will have a history of ocular trauma or recent ocular surgery. Any patient that presents after trauma requires a thorough history and physical exam consistent with advanced traumatic life support (ATLS) protocols. History should include questions related to the possibility of an intraocular foreign body, changes in vision, photophobia, eye pain, nausea, vomiting, and any history of bleeding diathesis, especially sickle cell disease or trait.

Evaluating for potentially open globes or penetrating eye injuries are crucial. All penetrating injuries should be assumed to have an associated open globe injury. In this case, all projectiles should be left in place, the eye should be protected with a shield, and the emergent ophthalmology consultation in the emergency department should be consulted. If trauma-induced, the patient should also be evaluated for acute orbital compartment syndrome. Signs of orbital compartment syndrome include proptosis, decreased visual acuity, and a relative afferent pupillary defect.

Once open globe and orbital compartment syndrome have been ruled out, a thorough evaluation can be done. Physicians should inspect the lids, lashes, lacrimal apparatus, and cornea. In addition, physicians should evaluate for direct and consensual pupillary responses and relative afferent pupillary defect. Visual acuity, confrontational visual fields, and extra-ocular muscles should be examined as well. Findings typical in the setting of hyphema include decreased visual acuity, photophobia, anisocoria, and the visual findings of blood in the anterior chamber.[2]

Visual acuity typically worsens with the supine position. Symptoms may improve with the elevation of the head due to the layering of blood below the visual axis. Decreased visual acuity is a result of the refractory changes induced by the blood in the anterior chamber. The normally clear, aqueous humor does not affect the path of light, whereas the RBCs will prevent light from focusing appropriately on the retina. Anisocoria results from tears to the iris sphincter muscles, which may cause either meiosis or mydriasis of the affected eye.

Clinicians grade hyphema by the amount of blood in the anterior chamber. Grade 0 or microhyphema occurs with scattered RBCs in the anterior chamber that do not layer out. Grade I hyphema has less than 33% anterior chamber filling. Grade II has 33% to 50% filling. Grade III has greater than 50%, but less than total filling of the anterior chamber, and grade IV has 100% anterior chamber filling.[1]

Evaluation

Following an initial physical exam, proceeding according to ATLS may be necessary if other traumatic injuries require imaging. For the specific evaluation of hyphema, a slit lamp examination is performed. On the slit lamp exam, fluorescein is used to assess for a corneal abrasion. This is done before the measurement of intraocular pressure, as using fluorescein later may result in false-positive corneal abrasion testing. After an open globe injury has been ruled out, intraocular pressure is measured. Any measurement greater than 21 mm Hg is considered elevated. A complete blood count (CBC) and coagulation profile on those with bleeding diathesis or anticoagulants is obtained and coagulopathies are corrected. Patients with a family history of sickle cell disease or trait or patients with uncertain status should be tested for sickle cell hemoglobinopathy.

Computerized tomography (CT) of the orbit should be utilized in patients with a concern for an open globe, an intraocular foreign body, or a suspected orbital fracture. Ultrasound of the orbit may be beneficial to evaluate for lens dislocation, intraocular foreign body, retinal detachment, and posterior vitreous hemorrhage.[8] Ultrasound should only be performed after open globe has been ruled out. Pressure on the eye from the ultrasound probe can cause extrusion of vitreous or aqueous humor and worsen the injury.

Treatment / Management

Treatment begins with identifying urgent threats to the eye site and other life-threatening conditions. As many hyphemas are the result of trauma, patients may present in need of endotracheal intubation for various other injuries. In this setting, succinylcholine is contraindicated secondary to the risk of increased intraocular pressure. If feasible, a non-depolarizing paralytic agent, such as rocuronium, is preferred. Likewise, ketamine has historically been contraindicated in the setting of open globe injuries or increased intraocular pressure. Recent data has called this axiom into question; nevertheless, if possible, it is prudent to avoid ketamine in a patient with hyphema.

Any patient with an orbital compartment syndrome requires immediate ophthalmology consultation and lateral canthotomy with cantholysis to decompress the globe. Intraocular pressure (IOP) should be measured before and after the procedure. The determination of adequate relief may be difficult as a concurrent hyphema may cause a persistently elevated pressure, persistent afferent pupillary defect, and persistent decrease in visual acuity. For this reason, it is imperative to perform the cantholysis with the canthotomy and to have immediate ophthalmology consultation in the emergency department.

For patients with an open globe injury, projectiles should be left in place. Patients should be provided adequate analgesia and anti-emetics. Coughing or sneezing may quickly increase pressures and cause more injury. A protective shield should be placed around any penetrating object to protect it from inadvertent dislodgement or further penetrance. The patient should have nothing by mouth (NPO), and ophthalmology should be consulted for emergency operative repair and removal. Prophylactic antibiotics against endophthalmitis should be started. The current recommendation is vancomycin 15 mg/kg and ceftazidime 2 g.[6] The globe is considered a sterile body location and systemic antibiotics generally do not penetrate the globe tissue. As a result, topical antibiotics are typically given during surgery as well. Tetanus status should be ascertained and updated as needed.

Hyphema treatment begins with elevating the head of the bed to at least 30 degrees. This allows the RBCs to layer inferiorly and out of the visual axis. Patients should also be instructed to sleep with the head of the bed elevated for the same reason. An eye shield should also be placed and worn until the hyphema has completely resolved. Topical analgesics, such as proparacaine or tetracaine, can be used to facilitate full exams and control pan.[9] Intravenous or oral opioid pain medications may also be necessary given the degree of pain which may be associated with an injury. Furthermore, nausea should be controlled. Recommendations include intravenous ondansetron up to 12 mg to control nausea. Vomiting will increase intraocular pressure and therefore, potentially resume bleeding and worsen intraocular hypertension.

Once acute glaucoma has been ruled out, topical cycloplegics may be used. Cyclopentolate 1%, using one drop three times daily with one drop, or scopolamine 0.25%, used one drop twice daily, can help with pain control. These medications paralyze the iris muscle as well, limiting “pupillary play”.[6] Pupillary play is constant constriction and dilatation of pupils stretching the previously injured vessels, which lead to re-bleeding. Cycloplegics should only be used once intraocular hypertension has been ruled out as they will dilate the iris, which further obstructs the outflow tract and worsens intraocular pressure. These medications should be prescribed solely in conjunction with an ophthalmologist who can continue to monitor for the development of increased pressures. Patients should additionally be advised to limit activity, including reading. Reading can cause pupillary dilatation and constriction which may increase the risk of re-bleeding.

Some ophthalmologists recommend topical steroid therapy. Topical steroids may limit healing if there are associated corneal abrasions, however, they will decrease the risk of re-bleeding. Commonly used preparations include prednisolone acetate 1% or dexamethasone sodium phosphate 0.1%.[10]

Patients with bleeding diathesis or coagulopathy should have their coagulopathy reversed or treated with required blood products in the setting of hemophilia or von Willibrand disease. Patients who are candidates for outpatient management must meet all the following criteria: grade II or less hyphema, normal intraocular pressure, no history of sickle cell disease or trait, no coagulopathy or bleeding diathesis, and ability to comply with daily ophthalmology evaluations. Any patient not meeting these criteria should be admitted for continued evaluation and management of complications as described below. All patients should be cautioned against the use of non-steroidal anti-inflammatory agents, aspirin, and anticoagulants until the resolution of hyphema.

Surgery to evacuate the hyphema is indicated in specific situations when complications of corneal blood staining or optic atrophy from prolonged elevated intraocular pressure occur. Surgical anterior chamber washout is indicated to prevent optic atrophy if the IOP averages greater than 60 mm Hg for 2 days, or greater than 35 mm Hg for 7 days. To prevent corneal blood staining, surgery is indicated if the IOP is greater than 25 mm Hg for 5 days, or if there is evidence of early corneal blood staining. To prevent anterior synechiae, surgery is indicated for a total hyphema that persists for 5 days, or any hyphema failing to reduce to a volume of less than 50% by day 8.[11][12] Sickle cell patients are at higher risk of dramatic IOP elevations due to the sickling of their red blood cells. Furthermore, surgery is indicated in these patients if the IOP averages greater or equal to 25 mm Hg for 24 hours, or if the IOP has transient elevations of greater than 30 mm Hg for 2 to 4 days.[13] 

Differential Diagnosis

• Complications and management of glaucoma filtering

• Herpes simplex virus keratitis

• Juvenile xanthogranuloma

• Ophthalmologic manifestations of sickle cell disease

• Uveitic glaucoma

Prognosis

Most patients will fully recover without deficits, however, complications are more likely in those with other comorbidities such as sickle cell disease or trait or increasing size of hyphema. For example, elevated intraocular pressure is seen in 13.5% of grade I to II hyphemas; whereas, there is a 52% risk with grade IV hyphemas. The prognosis for normal vision is also affected by the grade of hyphema. Grade I hyphemas have about 90% rate of normal vision; whereas, grade IV has only a 50% to 75% prognosis for normal vision.[14][2] The most common cause for vision impairment is corneal staining of the visual axis, which underscores the worsening prognosis for higher grade hyphemas.[1]

Complications

The 2 major acute complications of hyphemas are acute intraocular hypertension and re-bleeding.[15] Acute intraocular hypertension is most likely encountered in the emergency department. As the blood in the anterior chamber layers, it blocks the trabecular meshwork from adequately draining the combination of aqueous humor and blood.

Sickle cell disease deserves special attention in relation to hyphemas. As noted above, the clearance of a hyphema requires passage of the RBCs through the trabecular meshwork and the Canal of Schlemm. The anterior chamber, however, is relatively hypoxic, which induces sickling of RBCs in those at risk. As sickling worsens, the RBCs are unable to pass through the Canal of Schlemm, producing a rise in intraocular pressure.[16]

Any patient with intraocular pressure greater than 21 mm Hg should be treated similarly to non-traumatic acute glaucoma. An ophthalmologist should be consulted for management recommendations as there is no well-defined treatment strategy. A number of medications can be used to suppress aqueous inflow. These include topical beta-blockers, most commonly timolol, and topical alpha-2 agonists such as apraclonidine and brimonidine.[9] Carbonic anhydrase inhibitors, such as topical dorzolamide or systemic acetazolamide, are typically used as well, though caution should be taken as the use of these medications can worsen sickling in patients with sickle cell disease. As many different combinations of medications are available by brand name, it is recommended to discuss treatment options with an ophthalmologist for a directed treatment approach. About 5% of patients will have persistent or refractory intraocular hypertension requiring surgical clot evacuation.[1] 

Re-bleeding can occur two to five days later and can increase the risk of permanent visual loss. Re-bleeding is seen in about 30% of cases. In patients at higher risk (sickle cell, bleeding dyscrasias), the use of an antifibrinolytic such as epsilon-aminocaproic acid or tranexamic acid is no longer encouraged. Trials failed to demonstrate a decrease in rates of re-bleeding and time for hyphema resolution.[9]

Corneal blood staining is an uncommon complication that typically occurs in patients that have prolonged total hyphema. One case series (n=289 patients) found that 2.1% of the hyphemas developed corneal blood staining. This only occurred in patients with a total hyphema.[17] The recommended treatment for the prevention of corneal blood staining was an anterior chamber washout.

Consultations

All patients with hyphema should have an ophthalmology consultation in the emergency department, whether for daily follow up or for acute treatment if there is associated intraocular hypertension. 

Pearls and Other Issues

Hyphema is the collection of blood in the anterior chamber of the eye.

The most common cause of hyphema is blunt trauma, though spontaneous hyphemas can occur in the setting of sickle cell disease or other increased bleeding states.

Hyphemas are graded based on the degree of blood obscuring the cornea.

Once an open globe has been ruled out, intraocular pressure should be checked and treated if greater than 21 mm Hg.

All patients with hyphema require ophthalmology consultation.

Any patient with greater than grade II hyphema, elevated intraocular pressure, sickle cell disease, bleeding dyscrasias, coagulopathy, or unable to comply with daily ophthalmology evaluations should be admitted.

Re-bleeding will occur in about 30% of patients and may require surgical clot evacuation.

Enhancing Healthcare Team Outcomes

Hyphema is often seen in the emergency department, urgent care, or nurse practitioner clinic. These healthcare professionals play an important role in the management of this pathology. The most important step is to evaluate for any potentially open globe or penetrating eye injury. All penetrating injuries should be assumed to have an associated open globe injury. In this case, leave all projectiles in place, protect the eye with a shield and get emergent ophthalmology to consult in the emergency department. If trauma-induced, the patient should also be evaluated for acute orbital compartment syndrome. Signs of orbital compartment syndrome include proptosis, decreased visual acuity, and a relative afferent pupillary defect. If medications are required the pharmacist and nurse should assist the clinician with patient and family education regarding the importance of treatment and follow-up. An interprofessional team approach to evaluation and treatment involving primary care providers and specialists will result in the best outcomes. [Level 5]