BLINDED BY THE LIGHT

OCULAR ULTRASOUND BY DR LUKE PHILIPS


FACEM, MBBS, BSC(BIOMED)(HONS), CCPU

EMERGENCY CONSULTANT - ALFRED HEALTH

CO-DIRECTOR OF EMERGENCY MEDICINE TRAINING (THE ALFRED HOSPITAL)

CO-CHAIR OF THE EMUGs BOARD OF DIRECTORS.


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 ocular ultrasound was performed.


The Ultrasound


The 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.



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 and the patient was referred for an urgent ophthalmology 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.

  • 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


  • Ultrasound of the Week – Case 12

  • POCUS Toronto – Seeing Cleared With Ocular Ultrasound

  • The Diagnostic Accuracy of Bedside Ocular Ultrasonography for the Diagnosis of Retinal Detachment: A Systematic Review and Meta-analysis Vrablik, Michael E. et al. Annals of Emergency Medicine , Volume 65 , Issue 2 , 199-203.e1. https://doi.org/10.1016/j.annemergmed.2014.02.020

  • 5min Sono – Retinal vs Vitreous Detachment

Read: Introduction to Bedside Ultrasound Vol 2 – Chapter 16 (Free E-Book)