Hyphema is defined as accumulated red blood cells (RBC) 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 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 is an important anatomic location as this 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.
Blunt eye trauma is the most common cause, although penetrating trauma and spontaneously occurring hyphemas also occur. Certain medical conditions can also put patients at risk of developing a hyphema: leukemia, hemophilia, von Willebrand disease, sickle cell disease, and use of anticoagulant medications. Neovascularization of the eye, often associated with diabetes mellitus also puts patients at risk.
Lastly, post-surgical patients may develop hyphema. This may develop intraoperatively, but may also be delayed up to a week postoperatively.
The incidence of traumatic hyphema is 12 out of 100 000, with 70% occurring in children. 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 the course ball-related sports such as baseball, basketball, softball, and soccer when the ball strikes the anterior surface of the globe.
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.
Blunt or penetrating trauma usually causes traumatic hyphemas to the orbit. The bleeding comes from tears in the vessels of the ciliary body and iris. As a blunt force is applied to the anterior globe, there is an instantaneous increase in intraocular pressure, producing a shearing force across the ciliary body and iris. Penetrating trauma, however, produces a direct injury to the iris.
Spontaneous hyphemas often occur in patients whose medical conditions predispose 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.
Most patients will have a history of ocular trauma or recent ocular surgery. Any patient that presents after trauma deserves 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.
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 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.
Once open globe and orbital compartment syndrome have been ruled out, a thorough evaluation can be undertaken. Physicians should inspect the lids, lashes, lacrimal apparatus, and cornea. Evaluate for direct and consensual pupillary responses, as well as for a relative afferent pupillary defect. Visual acuity, confrontational visual fields, and extra-ocular muscles should all be evaluated. Findings typical in the setting of a hyphema include decreased visual acuity, photophobia, anisocoria, and the visual findings of blood in the anterior chamber.
The decreased visual acuity typically worsens with supine position. Symptoms improve with the elevation of the head due to the layering of the 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 does 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.
After your initial physical exam, if other traumatic injuries requiring imaging, proceed according to ATLS. For the specific evaluation of the hyphema, a slit lamp examination should be performed. On slit lamp exam, fluorescein should be used to asses for a corneal abrasion. Be sure to do this before measurement of intraocular pressure, as the later may result in false-positive corneal abrasion testing. After an open globe injury has been ruled out, intraocular pressure should be measured. Any measurement greater than 21 mm Hg is considered elevated. Obtain complete blood count (CBC) and coagulation profile on those with bleeding diathesis or anticoagulants and correct any coagulopathies. Any patient that has a family history of sickle cell disease or trait or patients with uncertain status should be testing for sickle cell hemoglobinopathy.
Computerized tomography (CT) of the orbit should be done in anyone with a concern for an open globe, an intraocular foreign body or when an orbital fracture is suspected. Ultrasound of the orbit may be beneficial to evaluate for lens dislocation, intraocular foreign body, retinal detachment, and posterior vitreous hemorrhage. It is important to note that 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, worsening the injury.
Treatment begins with identifying any urgent threats to 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 the 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 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, leave any projectiles in place. Provide 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 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 recommendations are for vancomycin 15 mg/kg and ceftazidime 2 g. The globe is considered a sterile body location and systemic antibiotics do not generally penetrate the globe tissue, for this reason, topical antibiotics are typically given during surgery as well. Tetanus status should be ascertained and updated as needed.
Treatments directed at the hyphema begins with elevating the head of the bed to at least 30 degrees. This allows the RBSs 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, which should be worn until the hyphema is completely resolved. To facilitate a full exam and for pain control, topical analgesics can be used. Topical proparacaine or tetracaine can be utilized. Intravenous or oral opioid pain medications may also be necessary given the degree of pain which may be associated with injury. Furthermore, nausea should also be controlled. Some recommendations include intravenous ondansetron up to 12 mg to control nausea. Vomiting will cause an increase in intraocular pressure and can cause re-bleeding as well as worsening intraocular hypertension. Once acute glaucoma has been ruled out, topical cycloplegics may be used. Cyclopentolate 1% one drop three times daily or scopolamine 0.25% one drop twice daily can help with pain control. The medicines will paralyze the iris muscle as well, limiting “pupillary play.” Pupillary play is the idea of constant constriction and dilatation of pupil stretching the previously injured vessels and leading to re-bleeding. Cycloplegics should only be used once intraocular hypertension has been ruled out as they will dilate the iris, which will further obstruct the outflow tract, worsening intraocular pressure. These should also only be prescribed in conjunction with an ophthalmologist who can continue to monitor for the development of increased pressures. Patients should also be advised to limit activity, including reading, for reading can also cause pupillary dilatation and constriction potentially increasing the risk of re-bleeding.
Some ophthalmologists also recommend topical steroid therapy. This should be arranged with whoever will continue to follow the patient. Topical steroids may limit healing if there is associated corneal abrasion, but also decrease the risk of re-bleeding. Commonly used preparations include prednisolone acetate 1% or dexamethasone sodium phosphate 0.1%.
Any patient with bleeding diathesis or coagulopathy should have their coagulopathy reversed or treated with required blood products in the setting of hemophilia of van 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 resolution of the hyphema.
Most patients will fully recover without deficits, but complications are more likely in those with other comorbidities such as sickle cell, and with 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. The most common cause for vision impairment is corneal staining of the visual axis, which underscores the worsening prognosis for higher grade hyphemas.
The 2 major acute complications of hyphemas are acute intraocular hypertension and re-bleeding. Acute intraocular hypertension is the complication most likely to be encountered in the emergency department. As the blood in the anterior chamber layers, it can block 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.
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, topical alpha-2 agonists such as apraclonidine and brimonidine. The use of carbonic anhydrase inhibitors is also typically used, though caution should be taken as the use of these medications can worsen sickling in patients with sickle cell disease. Examples include topical dorzolamide or systemic acetazolamide. Many different combinations of medications are available by brand name. Therefore it is recommended to discuss with an ophthalmologist for a directed treatment approach. About 5% of patients will have persistent or refractory intraocular hypertension requiring surgical clot evacuation.
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 was once encouraged. However, trials failed to demonstrate a decrease in rates of re-bleeding and a prolonged time for hyphema resolution.
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.
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.