Blinded by the Light

75yo Female presents to the ED with sudden onset right visual loss.  

  • Denies flashes/floaters and has no history of stroke/TIAs in the past.  She denies any symptoms of polymyalgia rheumatica or temporal arteritis.
  • Pt has a past history:
    • Cataracts but no surgery.  Wears glasses for reading.
    • Hypertension
    • Type 2 Diabetes
    • Atrial fibrillation – on Xarelto.
    • Non-smoker.
  • On exam:
    • Pupils equal, normal shape and reactive, normal eye movements
    • Normal visual acuity in left eye and unable to see anything from right eye
    • Normal eye pressures, no corneal abrasions and sclera not injected.
    • Non tender temporal artery with easily palpable pulse.
  • Investigations:
    • Normal ESR/CRP.
    • CT Brain – age related changes. No stroke, masses or intra-cranial haemorrhage.

I took over from overnight staff and reviewed the patient in the morning.  A point of care ultrasound was performed.

OCULAR POINT OF CARE ULTRASOUND.

Ultrasound demonstrates a macular off rentinal detachment. The thick undulating hyperechoic membrane in the posterolateral globe is always attached to the optic nerve posteriorly & the ora serrata anteriorly – Almost like a towel pegged on each end to a clothes line. The differential diagnosis is a vitreous detachment which tends to be more mobile, less uniform and is not attached to the optic nerve.

Eye Ultrasound anatomy
Ultrasound has a 97-100% Sensitivity for detecting retinal detachment & is 83-100% Specific in a recent meta-analysis.  Use as a rule in test.  If not visualised you may need to investigate further by dilating the pupil and looking at the retina with opthalmoscope or pan-optoscope.  The Time to diagnosis after I saw the patient was less than 10 minutes.

The patient was referred for an urgent opthalmology opinion.

HOW TO PERFORM AN OCULAR ULTRASOUND

  • Machine settings:
    • Linear Probe
    • Ocular setting (nerve if ocular unavailable)
    • PRO TIP: Turn up Gain to ensure subtle findings are not missed. 
  • Ensure barrier protection for eye – tegaderm over eye or probe cover
  • Use a large amount of ultrasound gel and hover the probe over the closed eye without exerting too much pressure on the globe.  Use with caution in patients with elevated eye pressures or globe rupture/suspected penetrating injuries.
  • This slideshow requires JavaScript.

  • Start in transverse in the mid-line.
    • Fan probe up and ask patient to look up
    • Fan probe down and ask patient to look down
  • Rotate Probe Longitudinally and Start in the mid-line.
    • Fan probe to left and ask patient to look left
    • Fan probe to right and ask patient to look right.

FURTHER RESOURCES

Leave a Reply

Please log in using one of these methods to post your comment:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s