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Speaker Name: MR AMIT KUMAR SINGH
Topic: "A quick guide to Ophthalmic Ultrasound/ B-Scan interpretation"
DATE – MONDAY, 11th MAY 2020 @ 01.45PM IST, 02.00PM NPT (GTM +5.45)
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A quick guide to Ophthalmic Ultrasound/ B-Scan interpretation
1. A quick guide to Ophthalmic
Ultrasound / B-Scan Interpretation
Amit K Singh
Consultant optometrist
Mechi Eye Hospital ,Birtamode-3 Jhapa
2.
3. Terminology
• Audible Range : 10-20,000 Hz
• Ultrasound : > 20,000 Hz
• Pulse echo system: piezoelectric transducer to generate
ultrasonic wave, a receiver which processes returning waves
and a display screen
• Acoustic impedance: Difference b/w strength of returning
echoes from tissue boundaries
• Angle of incidence: angle of sound beam relative to area of
interest
4. Terminology(contd)
• Resolution: ability to distinguish b/w adjacent echoes, both
axial & lateral
• Amplification: signal processing before echoes is displayed on
monitor
• Gain: procedure of increasing or decreasing amplitude of
echoes that are displayed on screen
• Time gain compensation(TGC) : technique used to enhance
returning echoes from deeper structures by reducing those
from structures closer to surface
5. Principle of B-scan
Electrical energy sound energy electronic energy
(Display)
• Abdominal ultrasound : 1-2 MHz
• Ophthalmic Ultrasound : 8-12 MHz
• Ultrasound Biomicroscopy : 35-100 MHz
• Frequency α 1/penetration α Resolution
PiezoelectricPiezoelectric
6. Indications of ocular B-scan
• Opaque media
1. Corneal opacity
2. A/c hyphema or hypopyon
3. Miosis
4. pupillary membrane
5. Cataract
6. Vitreous haemorrhage
7. • Clear media
1. Iris lesion
2. ciliary body lesion
3. Tumours & masses;detection & differentiation
4. RD :Rhegmatogenous vs exudative
5. IOFB detection and localization
6. OD abnormalities
8. Indications of orbital B-scan
• Enophthalmos
• Globe displacement
• Lid abnormalities
• Palpable or visible mass
• Chemosis
• Motility disturbance
• Pain
10. Ocular scans
• Probe positions
• Transverse : on sclera (@ TS)
• Longitudinal :at Limbus (@ LL)
• Axial : on cornea (@ AC)
• [NOTE: Markers aims nasally while screening superior &
Inferior and Superiorly for nasal & temporal]
11. Normal appearance of ocular & orbital
Structures
1. Lens
• Immersion/ stand off technique
• None to highly reflective intralesional
echoes depending on amount of cataract
2. Vitreous : Echo free , low to medium ref.
In vitreous degeneration.
3. Retina, choroid & sclera : seen as single
until/unless pathological conditions e.g.
RD,CD, scleritis
4. Optic Nerve: Wedge shaped acoustic void in
retrobulbar region
Vitreous Optic Nerve
12. Orbital Scans
• Probe placement
1. Transocular : lesions of mid & posterior orbit i.e. structures
within muscular cone (Opposite side )
2. Paraocular : lesions of lids & anterior orbit i.e. structures
beyond muscular cone (same side)
Transocular Scan Paraocular Scan
13. Extraocular Muscles(EOM)
• EOM are best evaluated by
transverse & longitudinal
scans.
• Echolucent to low
reflective fusiform str.
• SR-LPS complex : Thickest
• IR : Thinnest
• IO : Not imaged except in
pathological conditions
14. Description of a Lesion
• Location w.r.to easily demonstrable landmarks e.g. optic disc or lens
in an intraocular lesions
• Extent : both antero-posterior & lateral
• Dimensions: in cases of tumours and other solid lesions
• Shape & configuration : point like , membrane like or a mass
• Internal reflectivity : Echolucent ,low , moderate or high. Sclera has
100% reflectivity
• Structure : solid or cystic, regular or irregular
• Mobility : active movements and after movements
18. Angle of incidence artifact
Right Eye
Left Eye Left Eye
High reflective lesion (arrowhead)
Shifting of lesion s/o artifact
•Angle of incidence
artifact : probe is
perpendicular to surface
•Often mistaken with
IOFB, scar
25. Retinal Breaks & Detachment
Rhegmatogenous Tractional Exudative
Convex elevation Concave elevation Convex elevation
Tractional Band
Shifting of fluid with postural
change /by pressing with
finger
Supine position
Erect position
Open funnel shaped RD
29. RD Vs. PVD
•Restricted Aftermovement in kinetic scan
•High reflective membrane @ ONH
• Membrane thickness remains const. in
minimal tilt of probe
•Membrane visible at low gain
RD
•Free Aftermovement in kinetic
scan
•High reflective membrane may or
may not @ ONH
•Variable thickness in membrane
in minimal tilt of probe
•Membrane disappear at low gain
PVD
31. Retinoschisis Vs.Exudative RD/PED
Vs.
Choroidal Detachment (CD)
Retinoschisis Exudative RD Choroidal Detachment
Kissing choroidal sign
‘M’ spike
Dome shaped appearance
Shifting of fluid with postural
change /by pressing with
finger
No change in fluid /
structure by pressing with
finger
Supine
Erect100% single picked spike
seen just anterior Retina
100% single spike
32.
33. Intraocular Foreign Body
IOFB inside lens
IOFB @ Retinal surface
IOFB within Optic Nerve IOFB within anterior vitreous
34.
35. Endophthalmitis Vs. VKH syndrome
VKH SYNDROME
ENDOPHTHALMITIS
•U/L
•H/o Sx, Trauma
•PVD may or may not
present and develop
TRD
•Vitreous cells
•B/L
•Serous RD
• No PVD
•Few vitreous
opacities
36. Panophthalmitis Vs Posterior Scleritis
PANOPHTHALMITIS
POSTERIOR SCLERITIS
Marked thickening of the Ocular coats & low
reflective infiltration in Tenon’s capsule in
Panophthalmitis
‘T’-sign
37. Ocular Cysticercosis Vs Dislocated Lens
Scolex Lens Nucleus
In supine position Both seem to be same but in
erect position dislocated lens moves inferiorly
The live cyst does not cause inflammatory sign
53. Scleral Buckle Vs. Scleral folds
Thickening of RC complex (Arrowhead)
Scleral folds(Arrow)
Scleral Buckle(Arrowhead)
Scleral folds & Scleral buckles,esp. scleral
sponges have similar appearance on
ultrasound .But in case of folds hypotony
present .
54. Intraocular Air Vs PCIOL
IOL reverberationIntra ocular air reverberation
Spherical shadows floats opposite to the
direction of eye movement in Intraocular
air/gas
55.
56. Optic Nerve Thickening
•Normal diameter of retrobulbar
optic nerve : 2.2 – 3.3 mm
•Difference : ˃0.5 mm b/w two
nerves is of significance
•30˚ test : r/o Tumour from
Pseudotumour
Gross thickness Thickness deceases
Pseudotumour
Doughnut /Crescent sign
60. Gross Cupping
Optic Disc cupping
•Minimum cup disc ratio of
0.5 is necessary to detect
cupping on USG
•Medium gain
61. Reference
• Bhende M et al .(2013). Atlas of Ophthalmic Ultrasound and Ultrasound
Biomicroscopy. Jaypee Brothers Medical Publishers(P) Ltd, 2nd Edition
,ISBN 978-93-5090-535-7.
• Contact :amitasopto@gmail.com
• (+977-9819617489)
Editor's Notes
Reverberation artifacts : d/t insufficient coupling gel b/w eye & probe and due to IOLs & air gun pellets
Double membrane configuration
d/t polypoidal choroidal vasculopathy
shifting fluid changes with postural change
ICM :The neural retina continues as ICM in the area of the coloboma.
Persistence of Fetal Vasculature ,Persistent hyperplastic primary vitreous (PHPV),Retinopathy of Prematurity (ROP)