Case # 13: What Lies Beneath

A 30 year old male presents to the emergency department after blunt trauma to the face from an altercation. He notes he was punched several times in the face but did not pass out. His exam is notable for significant right periorbital ecchymosis and edema with inability to open his eye. You are unable to perform a direct eye exam given the significant periorbital swelling.  A CT maxillofacial is performed which shows an isolated right inferior orbital wall fracture.

Vitals: T 98.6 HR 85 BP 142/81  RR 14 O2 98% on RA

Prior to ENT consultation, a bedside ultrasound of the orbits is performed.  In spite of being unable to open the eye, what can you tell your consultant regarding your exam?

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Answer and Learning Points

Answer

Using ultrasound as an adjunct to your exam, you are able to tell the consultant that there is a normal appearing, reactive pupil and that the extra-ocular movements of the eye are intact. The consultant is appreciative over the phone and is happy to come in and see the patient whom after evaluation is discharged home with close outpatient follow up.

Learning Points

It is often the case where a patient suffers such significant facial trauma that a complete physical exam of the orbit due to periorbital swelling is not possible. Ultrasound can be a critical tool in these cases to provide useful information to assess for multiple potential pathologies. Previous studies have shown the ability of ocular ultrasound in trauma to detect elevated intracranial pressure (via optic nerve sheath diameter), retinal detachment, vitreous hemorrhage, and retrobulbar hematoma. It can also be used for early detection of muscular entrapment in the case of an orbital wall fracture, as well as performed serially for pupillary response in patients with significant neurological injury at risk for deterioration and potential herniation.

  • To evaluate extraocular movements:
    • Prepare the patient by laying the bed backwards and having their face parallel to the ceiling,  supporting the patient's head and neck with a pillow or blanket.
    • (Optional) Place a tegaderm over the eye. If you do, ensure there is no air between the tegaderm and the eyelid.
    • Place a small amount of ultrasound gel on the closed eyelid  and prepare the linear probe with the gain turned almost all the way up.
    • Stabilize your hand on the patient's nasal bridge or zygoma, with the probe marker to your left, and place the probe transverse on the orbit with minimal pressure being applied directly to the eye. This is very important in trauma as the area is likely painful and theoretically the patient could have a ruptured globe.
    • Adjust the depth to ensure the optic nerve is just visualized at the bottom of the screen. The anterior chamber and lens should be used as visual landmarks to ensure you are in proper location.
    • Next, have the patient look left and right, then turn the probe to a sagittal orientation and have the patient look up and down. During these maneuvers you should be evaluating for symmetric movements of the orbit in each direction.
    • If you do not appreciate symmetric movements of the orbit in all directions then you may have entrapment of an extraocular muscle.
  • To evaluate for pupillary response and shape:
    • Be sure to dim the lights in the room prior to performing this exam to allow for an adequate pupillary response.
    • Gently apply the linear probe with gel in a transverse plane just inferior to the eye, angling superiorly towards the patient's head (Depending on the location of the swelling around the eye, you can also place the probe superior to the eye, angling inferiorly towards the patient's feet).
    • Keep flattening out your probe angle relative to the skin until you have a cross section of the pupil and iris in view.
    • The pupil should be evaluated for symmetry as an asymmetric or oblong pupil could suggest globe rupture. You can then shine a light in the affected or non-affected eye (consensual light reflex) and observe the pupil for constriction.

 

Author

This post was written by Michael Macias, MD, Ultrasound Fellow at UCSD.

References

    1. Blaivas M. Bedside emergency department ultrasonography in the evaluation of ocular pathology. Acad Emerg Med 2000;7:947-50.
    2. Blaivas M, Theodoro D, Sierzenski P. A study of bedside ocular ultrasonography in the emergency department. Acad Emerg Med 2002;9(8):791-9.
    3. Kimberly HH, Shah S, Marill K, Noble V. Correlation of optic nerve sheath diameter with direct measurement of intracranial pressure. Acad Emerg Med 2008;15(2):201-4.
    4. Tayal VS, Neulander M, Norton HJ, et al. Emergency department sonographic measurement of optic nerve sheath diameter to detect findings of increased intracranial pressure in adult head injury patients. Ann Emerg Med 2007;49(4):508-14.
    5. Harries A, et al. Ultrasound assessment of extraocular movements and pupillary light reflex in ocular trauma. Am J Emerg Med 2010 28(8):956-9.

Case # 12: Bilateral Vision Loss

A 45 year old male with poorly controlled DM presents with bilateral vision loss. His right eye vision acutely worsened 3 days ago with the sensation of a curtain moving back and forth across his visual field. Today his left eye vision acutely worsened with flashes and floaters occurring. He denies any trauma, headache, or new medications.

Vitals: T 98.6 HR 90 BP 149/87  RR 16 O2 98% on RA

A bedside ultrasound of the orbits is performed,  what is the next best step in management?

Left Eye

Left Eye

Right Eye

Right Eye

Answer and Learning Points

Answer

The ultrasound clips demonstrate hypoechoic material in the orbits bilaterally, swirling around with subtle eye movement. This is consistent with bilateral vitreous hemorrhage. The diagnosis was discussed with the patient and he was referred to ophthalmology clinic for dilated eye exam in 24 hours.

Learning Points

Vitreous hemorrhage is a common diagnosis (though usually unilateral) seen in poorly controlled diabetes. The most frequent etiologies include proliferative diabetic retinopathy, posterior vitreous detachment, and ocular trauma, with trauma more common in patients under the age of 40. Since it is difficult to obtain  a good physical exam of the posterior aspects of the eye without a dilated exam, there is high utility in the use of point of care ultrasound in evaluating for acute pathology.  It can be used to distinguish vitreous hemorrhage and retinal detachment, which have significantly different prognoses and treatment pathways. To perform an ocular ultrasound, follow these steps:

    1. Prepare the patient by laying the bed backwards and having their face parallel to the ceiling,  supporting the patient's head and neck with a pillow or blanket.
    2. Place a tegaderm over the eye (optional). If you do, ensure there is no air between the tegaderm and the eyelid.
    3. Place the ultrasound gel on the tegaderm and prepare the linear probe with the gain turned almost all the way up (this will help you visualize both retinal detachment and vitreous hemorrhage.
    4. Stabilize your hand on the patient's nasal bridge or zygoma, with the probe marker to your left, and place the probe transverse on the orbit with minimal pressure being applied directly to the eye.
    5. Adjust the depth to ensure the optic nerve is just visualized at the bottom of the screen. The anterior chamber and lens should be used as visual landmarks to ensure you are in proper location. Next, have the patient look up, down , left and right (oculokinetic echography), to assess for any abnormalities in the posterior aspects of the eye.
    6. Repeat this technique with the probe marker pointed superiorly and have the patient again look in all directions.

Retinal detachment: The common POCUS findings include a thin linear structure tethered to the optic nerve.  It flaps back and forth as the eye is moved giving it the appearance of “swaying seaweed”. This is an ophthalmologic emergency, especially if the macula is still attached,  the ophthalmologist should be immediately consulted.

Vitreous hemorrhage: You will notice a diffuse mobile opacity often described as a “snow globe” that is exacerbated with moving the eye from side to side. If this is seen in a diabetic patient with floaters, there is a high likelihood that the diagnosis is a vitreous hemorrhage. These patients will still need follow up with ophthalmology for further management, but typically there will not be an emergent intervention.

Author

This post was written by Sam Frenkel, MD, PGY-2 UCSD EM. It was reviewed by Michael Macias, MD, Ultrasound Fellow at UCSD.

References

    1. Yoonessi R, Hussain A, Jang TB. Bedside ocular ultrasound for the detection of retinal detachment in the emergency department. Acad Emerg Med. 2010;17(9):913-7.
    2. Dawson, Mallin. Introduction to Bedside Ultrasound, Volume 2. 2013. Apple iBook.
    3. Kilker B, Holst J, Hoffmann B. Bedside ocular ultrasound in the emergency department. Eur J Emerg Med. 2014;21(4):246-253.
    4. Shinar Z, Chan L, Orlinsky M. Use of ocular ultrasound for the evaluation of retinal detachment. J Emerg Med. 2011;40(1):53-57.