ocular ultrasound lecture

1. OCULAR ULTRASOUND
TECHNIQUE, EVIDENCE, PATHOLOGY

2. 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. 3% of all ED visits
Ocular Emergencies

6. Retinal detachment
!
Vitreous hemorrhage
!
Vitreous detachment
!
Foreign body
!
Lens dislocation
!
Retrobulbar hematoma
!
Pupillary light reflex
!
Optic nerve sheath diameter

7. Contraindications
Obvious or suspected globe
rupture
!
Significant peri-orbital
injuries
!
Suspected clinically
significant retrobulbar
hematoma

10. Sensitivity 100%
Specificity 97.2%
PPV 96.2%
NPV 100%
Ability of ER docs to diagnose ocular pathology
in patients with acute visual change

11. Technique

16. Air Versus Water
H2O

17. AIR
Air Versus Water

18. ! 8 – 14 MHz Frequencies
! Linear array
! Linear scan format
! Medium Footprint
! Advantage: BEST resolution
of superficial structures
What Probe?

29. Gel
Brace Hand

30. Tegaderm
over Eye(???)

31. Image in Two Planes
Transverse Sagittal

32. Too much pressure
Damage Structures with
Ruptured Globe

33. Eye Shield
CT of the Orbits
What do you do if
Globe Rupture is
suspected?

34. “USE
LOTS
OF
GEL”
- Geoff Hayden

35. Dip End of Transducer in Gel

36. ANATOMY
& IMAGING

37. 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)

39. Anterior
Segment
Posterior
Segment

40. LENS
Anterior Segment
Posterior Segment

41. ANTERIOR SEGMENT
CORNEA
!
AQUEOUS HUMOR
!
IRIS
!
LENS

42. .
POSTERIOR SEGMENT
Vitreous body
!
Retina
!
Sclera
(surrounds 4/5 of
posterior surface of eye)

43. Anterior
Chamber
Posterior
Chamber
IRIS separates “Chambers”

44. IRIS
Anterior
Chamber
Posterior
Chamber

49. PATHOLOGY

50. OCULAR TRAUMA
INCREASED ICP

51. OCULAR TRAUMA
GLOBE RUPTURE
!
DISLOCATED LENS
!
RETINAL DETACHMENT
!
VITREOUS HEMORRHAGE
!
FOREIGN BODY

52. OCULAR ULTRASOUND
Ocular Trauma
DIFFICULT EXAM
Periorbital Swelling
Patient Non-compliance
Clinician Inexperience
Damage to Anterior Segment

53. CASE 1

54. ULTRASONIC FINDINGS
Loss of Intraocular Volume & Height
“Flat Tire” Sign
Intraocular Echogenic Material
or Air

55. GLOBE RUPTURE
Decrease in size of
globe
!
Anterior chamber
collapse
!
Bucking of sclera

56. IMAGING
“GOLD STANDARD”
Maxillofacial CT
Ultrasound is CONTRAINDICATED in a
patient with known or “highly
suspected” globe rupture.

57. Rupture most likely at insertion of
extraocular muscles
(where sclera is thinnest)
CT sensitivity for clinically occult
rupture is low (about 60%)

58. CASE 2

59. PHYSICAL EXAMINATION
Vital Signs Normal
OD: 20/30; OS: 20/200
Pupils equally reactive to light
Can not see OS retina with
ophthalmoscope

61. When in doubt, turn up the gain

63. 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

64. CASE 3

65. 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.

68. Sudden Painless Vision Loss
Photopsias (Flashes of Light)
Visual “Floaters”
“Curtain” of Vision Loss

69. ORA SERRATA
(layer between retina
and choroid)
OPTIC NERVE

70. RISK FACTORS
Myopia
Cataract Surgery
Diabetes
Sickle Cell Disease
Trauma
ACUTE NON-TRAUMATIC VISION LOSS
Retinal Detachment

71. 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.

72. PROGNOSIS with
MACULAR SPARRING
Central Vision Preserved
Emergency Surgical Repair to
prevent further damage

73. PROGNOSIS without
MACULAR SPARRING
Central Vision Lost
Less-urgent repair
(the damage is done)
Ophthalmologist MUST make determination if
Macula is “ON” or “OFF”

75. FUNNEL RETINAL DETACHMENT

77. CASE 4

78. 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

79. Vitreous Hemorrhage
Retinal Detachment
Ruptured Globe
Lens Dislocation
Optic Nerve Injury
Retrobulbar Hematoma
OCULAR TRAUMA
Differential Diagnosis

82. Treatment
POSTERIOR DISLOCATION
Surgical Repair

83. Treatment
ANTERIOR DISLOCATION
Cycloplegics and Beta-antagonist to
decrease intraocular pressure
Ocular Massage to move the lens
back into position

84. CASE 4a

86. CASE 5

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

88. LUMBAR PUNCTURE
Normal CSF
Opening Pressure 50
CT SCAN
Normal Ventricular Size
No Intracranial Mass

89. 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

91. 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

93. CSF IN HERE HOLES HERE

94. OPTIC NERVE SHEATH DIAMETER
Optic nerve inserts
medially on globe
!
Measure diameter 3 mm
posterior to retina
!
Cutoffs for increased ICP

96. Swollen optic disc

97. Case 6

98. PHYSICAL
EXAMINATION
Initial GSC of 12
CT of Head Notable for
Intracranial Bleed
In ICU patient
deteriorates and is
intubated

99. 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

102. Ultrasound for Evaluation of
Increased Intracranial Pressure
THE EVIDENCE

103. 2011
10 adult patients with pseudotumor enrolled
!
Measured ONSD before and after LP
!
Cutoff for increased ICP= 5.8
!
90% Sensitivity; 84% Specificity

104. 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

105. 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

106. 2009
ONSD threshold of 5.2 mm as a predictor of
ICP > 20 mm Hg
!
96% Sensitivity
94% Specificity

107. 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

108. 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

109. PEARLS & PITFALLS

110. Too much or too little gain

111. IF RUPTURED GLOBE SUSPECTED

112. CAN’T FIND THE OPTIC NERVE?

113. 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)

114. USE LOTS OF GEL

115. FINAL THOUGHTS