OCULAR ULTRASOUND

TECHNIQUE, EVIDENCE, PATHOLOGY

5objectives

1. Provide background on ocular ultrasound and put it into context

!2. Review ocular anatomy and how each structure looks

on ultrasound !3. Discuss the technique and point-of-care questions you

want to answer !4. Review specific pathology that can be evaluated

with point-of-care ocular ultrasound !5. Review key pearls and pitfalls

3% of all ED visits

Ocular Emergencies

Retinal detachment !

Vitreous hemorrhage !

Vitreous detachment !

Foreign body !

Lens dislocation !

Retrobulbar hematoma !

Pupillary light reflex !

Optic nerve sheath diameter

Contraindications

Obvious or suspected globe rupture !

Significant peri-orbital injuries !

Suspected clinically significant retrobulbar hematoma

Sensitivity 100% Specificity 97.2%

PPV 96.2% NPV 100%

Ability of ER docs to diagnose ocular pathology in patients with acute visual change

Technique

Air Versus Water

H2O

AIR

Air Versus Water

!  8 – 14 MHz Frequencies !  Linear array !  Linear scan format ! Medium Footprint !  Advantage: BEST resolution

of superficial structures

What Probe?

Gel

Brace Hand

Tegaderm over Eye(???)

Image in Two PlanesTransverse Sagittal

Too much pressure

Damage Structures with Ruptured Globe

Eye Shield CT of the Orbits

What do you do if Globe Rupture is

suspected?

“USE LOTS OF GEL”

- Geoff Hayden

Dip End of Transducer in Gel

ANATOMY & IMAGING

Point-Of-Care Questions

Can you identify all key anatomic structures?

!

Is a ruptured globe present? !

Is an ocular foreign body present?

!

Is there increased intracranial pressure

(optic nerve sheath diameter measurement)

Anterior Segment

Posterior Segment

LENS

Anterior Segment

Posterior Segment

ANTERIOR SEGMENT

CORNEA !

AQUEOUS HUMOR !

IRIS !

LENS

.

POSTERIOR SEGMENT

Vitreous body !

Retina !

Sclera (surrounds 4/5 of

posterior surface of eye)

Anterior Chamber

Posterior Chamber

IRIS separates “Chambers”

IRIS

Anterior Chamber

Posterior Chamber

PATHOLOGY

OCULAR TRAUMA

INCREASED ICP

OCULAR TRAUMAGLOBE RUPTURE

!

DISLOCATED LENS !

RETINAL DETACHMENT !

VITREOUS HEMORRHAGE !

FOREIGN BODY

OCULAR ULTRASOUND Ocular Trauma

DIFFICULT EXAM Periorbital Swelling

Patient Non-compliance Clinician Inexperience

Damage to Anterior Segment

CASE 1

ULTRASONIC FINDINGS Loss of Intraocular Volume & Height

“Flat Tire” Sign Intraocular Echogenic Material

or Air

GLOBE RUPTURE

Decrease in size of globe

!

Anterior chamber collapse

!

Bucking of sclera

IMAGING “GOLD STANDARD”

Maxillofacial CT

Ultrasound is CONTRAINDICATED in a patient with known or “highly

suspected” globe rupture.

Rupture most likely at insertion of extraocular muscles (where sclera is thinnest)

CT sensitivity for clinically occult rupture is low (about 60%)

CASE 2

PHYSICAL EXAMINATION Vital Signs Normal

OD: 20/30; OS: 20/200 Pupils equally reactive to light

Can not see OS retina with ophthalmoscope

When in doubt, turn up the gain

ACUTE NON-TRAUMATIC VISION LOSS Vitreous Hemorrhage

RISK FACTORS Diabetes Trauma

Retinal Tears

SYMPTOMS Floaters Flashes

Cloudy Vision

Bleeding from Fragile Vessels in Vitreous Space

CASE 3

PHYSICAL EXAMINATION Vital Signs Normal

OD: 20/30; OS: fingers only Pupils equally reactive to light

Vision worse with inferior & right gaze. No neurologic deficits.

Sudden Painless Vision Loss Photopsias (Flashes of Light)

Visual “Floaters” “Curtain” of Vision Loss

ORA SERRATA (layer between retina

and choroid)

OPTIC NERVE

RISK FACTORS Myopia

Cataract Surgery Diabetes

Sickle Cell Disease Trauma

ACUTE NON-TRAUMATIC VISION LOSS Retinal Detachment

In this paperJ Emerg Med. 2011 Jan;40(1):53-7. Epub 2009 Jul 21.

Use of ocular ultrasound for the evaluation of retinal detachment. Shinar Z, Chan L, Orlinsky M.

RESULTS: Thirty-one of the 72 practitioners trained submitted ocular ultrasound reports on patients presenting to the Emergency Department with concerns for retinal detachments. EPs achieved a 97% sensitivity (95% confidence interval [CI] 82-100%) and 92% specificity (95% CI 82-97%) on 92 examinations (29 retinal detachments). Disc edema and vitreous hemorrhage accounted for false positives, and a subacute retinal detachment accounted for the only false negative.

PROGNOSIS with MACULAR SPARRING Central Vision Preserved

Emergency Surgical Repair to prevent further damage

PROGNOSIS without MACULAR SPARRING

Central Vision Lost Less-urgent repair

(the damage is done) Ophthalmologist MUST make determination if

Macula is “ON” or “OFF”

FUNNEL RETINAL DETACHMENT

CASE 4

PHYSICAL EXAMINATION Vital Signs Normal

OD: light only; OS: 20/30 with correction Swelling to OD Periorbital Structures

Dilated Pupil No Hyphema or Corneal Injury

Vitreous Hemorrhage Retinal Detachment

Ruptured Globe Lens Dislocation

Optic Nerve Injury Retrobulbar Hematoma

OCULAR TRAUMA Differential Diagnosis

Treatment POSTERIOR DISLOCATION

Surgical Repair

Treatment ANTERIOR DISLOCATION

Cycloplegics and Beta-antagonist to decrease intraocular pressure

Ocular Massage to move the lens back into position

CASE 4a

CASE 5

PHYSICAL EXAMINATION VA 20/40 OS, 20/40 OD, 20/40 OU External Ocular Exam is Normal

LUMBAR PUNCTURE Normal CSF

Opening Pressure 50

CT SCAN Normal Ventricular Size

No Intracranial Mass

Female Predominance Associated with Various Meds

Chronic Daily Headaches and Nausea Monocular & Binocular Blurred Vision

Pulsatile Tinnitus

Idiopathic Intracranial Hypertension (Pseudotumor Cerebri)

Goals of therapy: Symptom relief & Preservation of vision

THE PROBLEM WITH PAPILLEDEMA (ON NON-DILATED FUNDOSCOPIC EXAM)

Limited in physical exam in eye/head trauma (not always practical)

!

Lags behind elevations in intracranial pressure (late sign)

!

Indirect & not dynamic measure !

Subjective

CSF IN HERE HOLES HERE

OPTIC NERVE SHEATH DIAMETER

Optic nerve inserts medially on globe

!

Measure diameter 3 mm posterior to retina

!Cutoffs for increased ICP

Swollen optic disc

Case 6

PHYSICAL EXAMINATION Initial GSC of 12

CT of Head Notable for Intracranial Bleed

In ICU patient deteriorates and is

intubated

Extension of Dura Mater Direct communication with Brain

Increased ONS is Indicator of Increased ICP

ONSD < 5mm rules out Elevated ICP in Adults and Children

OPTIC NERVE SHEATH

Ultrasound for Evaluation of Increased Intracranial Pressure

THE EVIDENCE

2011

10 adult patients with pseudotumor enrolled !

Measured ONSD before and after LP !

Cutoff for increased ICP= 5.8 !

90% Sensitivity; 84% Specificity

Prospective blinded observational study !

All had invasive intracranial ICP monitors !

38 US performed on 15 patients !

ONSD>5 mm detected ICP> 20 mm Hg with 88% sensitivity and 93% specificity

2008

Prospective blinded observational study with suspected intracranial injury with increased ICP

!Mean binocular ONSD> 5 mm

!Compared to CT findings of increased ICP

!Sensitivity 100%, Specificity 64%

!US of ONSD may be a sensitive test for increased ICP

2009

ONSD threshold of 5.2 mm as a predictor of ICP > 20 mm Hg

!

96% Sensitivity 94% Specificity

Children 0-18 years !

Compared to imaging or invasive ICP monitor !

4mm in children < 1 year, 4.5 mm in older children !

83% Sensitivity; 38% specificity

ONSD appears to be highly sensitive for elevated ICP. However, it is not specific.

Interreader reliability issues

How would you use? Patient with altered

mental status !

Is it good enough to avoid doing CT before

LP? Jury is still out

PEARLS & PITFALLS

Too much or too little gain

IF RUPTURED GLOBE SUSPECTED

CAN’T FIND THE OPTIC NERVE?

SCAN IN 2 PLANES !

COMPARE AFFECTED TO UNAFFECTED

EYE !

HAVE PATIENT MOVE EYE IN ALL

DIRECTIONS (so you can see all

portions of the globe)

USE LOTS OF GEL

FINAL THOUGHTS