Annals of B-Pod: An Ocular Emergency
/A Case of Retrobulbar Hematoma
The patient is a female in her 60s who presents by EMS after a fall in a parking lot approximately one hour prior to arrival. She fell forward and landed on her face. She believes she simply tripped and fell, but she did lose consciousness and does not know how she ended up on the ground. Per family, she is unsteady on her feet and falls frequently, requiring a cane at baseline. She reports feeling “weak” but no other symptoms preceding her fall. She presents with significant right-sided facial trauma and is unable to open her right eye. She has no complaints of blurry vision in her left eye. She has no headache or other areas of pain or trauma.
Physical Exam
CT Maxillofacial without contrast. There is proptosis of the right eye, with teardrop sign as well as retro-orbital stranding consistent with blood in the orbital compartment
T 98.7 HR 68 RR 22 BP 220/65 SpO2 95% on RA
General: Elderly female with significant trauma to her right eye, face, lip, and bloody clothing. Awake, alert, appropriate, conversational.
HEENT: Patient with significant facial trauma: Right eye swollen shut, with significant surrounding ecchymoses and swelling over right maxilla. Right eye is proptotic, with significant chemosis, fixed mid dilated pupil not reactive to light, patient able to tell light vs. dark but cannot see movement. Patient able to move eye only very slightly. Left eye atraumatic with round and reactive pupil and full extraocular motions. Right maxilla with overlying swelling, no pain on palpation of the face, no battle sign
Neck: supple, trachea midline, no C-spine tenderness
Pulmonary: CTA b/l, no chest wall tenderness
Cardiac: RRR no MRG
Abdomen: soft, NTND, no bruising or signs of trauma, pelvis stable
Musculoskeletal: Atraumaic exam except as described above
Neuro: GCS 15, AAOx4, cranial nerves II - XII grossly intact except for R eye exam as documented above, symmetric face, gait exam deferred secondary to chief complaint; strength 5/5 in all four extremities; sensation grossly intact
Hospital Course
The patient presented one hour after facial trauma with a proptotic right eye, only light/dark differentiation in that eye, as well as loss of extra-ocular movements and an afferent pupillary defect. Together, these findings were classic for retrobulbar hematoma. This was corroborated on her maxillofacial CT. Due to the patient’s significant vision deficits on presentation, a right lateral canthotomy with cantholysis was performed urgently at bedside, with successful release of the upper and lower canthal ligaments. After the procedure, the patient had no improvement in her vision, and worsened from light/dark perception to complete vision loss. Her IOPs remained persistently elevated in above 80 mm Hg. Her IOP was acutely managed with timolol drops as well as mannitol, with some improvement in her IOPs. She was admitted for a syncope workup, management of her ophthalmologic issues , and multiple orbital and mid-face fractures. The patient ultimately suffered complete vision loss in her right eye.
Management of Retrobulbar Hematomas
Retrobulbar hematoma, which can also be conceptualized as “orbital compartment syndrome,” is a vision-threatening condition and ophthalmologic emergency. Retrobulbar hemorrhage has been described after trauma as well as after facial surgery, and this presentation may be delayed up to days after injury. [2] This is an uncommon condition, even in the setting of orbital fracture – only 0.45-0.6% of patients with orbital fracture have a coexisting retrobulbar hematoma. However, it is quite morbid, as patients who present with vision loss in the setting of retrobulbar hemorrhage have a 44-52% chance of permanent blindness. The retina may tolerate approximately two hours of ischemia before vision loss is irreversible. [1]
Bleeding into the orbital space increases pressure in a closed cavity. With increased intra-orbital pressure, the globe is displaced anteriorly until it is tethered by the canthal ligaments, resulting in a compressive neuropathy. The optic nerve stretches and suffers ischemia as the globe is displaced anteriorly. Additionally, the pressure in the central retinal artery cannot overcome increased IOP, leading to retinal ischemia. Together, these factors result in the classic proptotic eye with an afferent pupillary defect and progressive vision loss. Additionally, patients may have eye pain, ophthalmoplegia, and findings on fundoscopic exam such as a cherry red macula and nerve head pallor. Intraocular pressures with these secondary findings are typically >40 mm Hg. [3]
Lateral canthotomy with cantholysis is the treatment of choice for decompression of the orbit after retrobulbar hematoma. The only contraindication to lateral canthotomy include suspected globe rupture.
Diagram by Riley Grosso, MD. This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
Ideally, decompression is performed as soon as possible after the injury, to mitigate the effects of ischemia on the nervous structures of the orbit. If decompression is unsuccessful in lowering IOP, adjunctive therapies include pharmacologic interventions to decrease intra-ocular pressure by reducing the production of aqueous humor (similar to the acute treatment of glaucoma), including beta blocker drops such as timolol and carbonic anhydrase inhibitors such as acetazolamide. Additionally, hyperosmotic agents such as mannitol may also be used to try to decrease edema contributing to increased IOP. [4] These patients require prompt Ophthalmology evaluation and follow-up.
In summary, retrobulbar hemorrhage is an uncommon but time-sensitive, highly morbid condition that carries an approximately 50% chance of vision loss for the patient. Timely recognition and intervention at bedside with a lateral canthotomy with cantholysis can help prevent further ischemic damage to the nervous structures of the eye and help to mitigate vision loss for the patient.
Authored by: Courtney McKee, MD
Posted by Grace LaGasse, MD
References
1. Ballard SR, Enzenauer RW, O’Donnell T, Fleming JC, Risk G, Waite AN. Emergency lateral canthotomy and cantholysis: a simple procedure to preserve vision from sight threatening orbital hemorrhage. J Spec Oper Med. 2009 Summer. 9(3):26-32.
2. Holt GR, Holt JE. Incidence of eye injuries in facial fractures: an analysis of 727 cases. Otolaryngol Head Neck Surg. 1983 Jun. 91(3):276-9.
3. McInnes G, Howes DW. Lateral canthotomy and cantholysis: a simple, vision-saving procedure. CJEM. 2002 Jan;4(1):49-52.
4. Peak, DA, Green TE. Acute Orbital Compartment Syndrome. Medscape. Updated Nov. 5, 2015.
