Ocular

 Learning Objectives:

  1. Describe the indications, limitations, and relative contraindications of ocular US

  2. Perform bedside US protocol for evaluation of basic and advanced indications 

  3. Identify relevant US anatomy of orbital structures


Indications:

  • Vitreous hemorrhage

  • Posterior vitreous detachment

  • Retinal detachment

  • Optic nerve sheath diameter measurement

  • Optic disc evaluation

Extended Indications:

  • Lens dislocation

  • Intraocular Foreign Body 

  • Central retinal artery / vein occlusion

  • Light reflex

Required Views:

Transverse (short) view of the right eye. Ensure to scan both right and left for credit.

c/o Victoria Gonzalez, MD

Sagittal (long) view of the right eye. Ensure to scan both right and left for credit.

c/o Victoria Gonzalez

Measure the optic nerve sheath diameter (ONSD) 3mm from the back of the eye. The ONSD should measure <5mm across.

c/o John Elue, MD

Evaluate the eye with ocular ultrasound as the patient moves their eye(s) left/right/up/down.

c/o John Elue, MD

How to Scan:

​​ACEP Sonoguide - Ocular Emergencies

Core Ultrasound- Ocular

POCUS101 - Ocular US

Tips/Tricks/Pitfalls:

  • Probe marker should point toward the temple (this is the side of the macula) 

  • Anchor your hand/pinky on a bony structure of the patient’s face to avoid placing too much pressure on the eye

  • Use copious amounts of US gel and minimal direct pressure on the eye

  • The retina is attached at the ora serrata and the optic nerve

  • Retinal detachment may be distinguished from posterior vitreous detachment because the retina is a thicker structure and is tethered at the ora serrata and the optic nerve

  • Remember the 3x5 iindex card rule to remember ONSD measurement (measure 3mm posterior to retina, <5mm across is normal)

  • Ocular US is relatively contraindicated if you suspect globe rupture or if there are periorbital wounds

  • Use oculokinetics  (ask the patient move their eye during your US) to reveal vital information and ensure you don’t miss pathology

Pathology:

Mac off retinal detachment. Retina tethered at optic nerve.

c/o Melissa Hoshizaki, MD

CRAO with Intra-arterial spot sign (hyperechoic spot) in optic nerve.

c/o Susan Mari, MD

Vitreous hemorrhage displaying “washing machine” sign.

c/o Rayyan Kadi, MD

Lens dislocation

c/o Tim Wyman, MD

Dilated ONSD (7.6mm) with cupping in a patient with optic neuritis.

c/o Adrian Roblesi, MD

Ocular metastasis

c/o Kevin Boubouleix, MD