This document is a comprehensive guide to ophthalmic ultrasound and B-scan interpretation, providing detailed terminology, principles, and techniques for evaluating various ocular conditions. It covers ultrasound frequency ranges, indications for scans in both ocular and orbital assessments, normal appearances, and descriptions of lesions. The guide also includes information on different ocular pathologies, their ultrasound characteristics, and distinctions between similar conditions.

1. A quick guide to Ophthalmic
Ultrasound / B-Scan Interpretation
Amit K Singh
Consultant optometrist
Mechi Eye Hospital ,Birtamode-3 Jhapa

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

9. Technique of Evaluation
• Clinical correlation

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

16. Reverberation Artifacts
Dropped IOL
Si oil Reverberation
PCIOL Reverberation
Artifact d/t Insufficient Coupling

17. Shadowing
• Shadowing: d/t Ca,glass,bone ,air
metal ,gas
Shadowing

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

19. Vitreous Hemorrhage
Low gain
High gain

20. Subhyaloid hemorrhage
Increases echoes in inferior quadrant
PVD

21. Vitreoschisis
Double membrane configuration

22. Vitreous Hemorrhage with Retinal tear
Retinal Tear(Arrow)
VH

23. Posterior Vitreous Detachment

24. Vitreous hemorrhage with hemorrhagic PED
VH
Hemorrhagic PED

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

26. RRD with PVR
PVR
Open funnel shaped RD

27. Closed funnel shaped RD with cyst formation
Cyst
Closed funnel shaped RD
Cyst

28. RRD with Giant retinal tear
GRT

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

30. Hemorrhagic choroidal detachment
(Expulsive)
Kissing choroid with suprachoroidal hemorrhage

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

33. Intraocular Foreign Body
IOFB inside lens
IOFB @ Retinal surface
IOFB within Optic Nerve IOFB within anterior vitreous

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

39. Choroidal Melanoma
Vs.
Choroidal Hemangioma
Acoustic Hollowing
Choroidal Melanoma Choroidal Hemangioma

40. ONH Melanocytoma
High reflective mass over ONH

41. Choroidal Melanoma Vs. Choroidal Metastases
CHOROIDAL MELANOMA CHOROIDAL METASTASES
Regular Contour
Irregular contour

42. Retinoblastoma
Calcification

43. Choroidal Osteoma Vs Phthisis Bulbi
Double Optic Nerve like appearance
Plaque like calcification
Coats Calcification

45. Coloboma of the Choroid & Optic Disc
Detached ICM(Thick Arrow)
Large optic disc coloboma
Chorio -retinal coloboma
Scleral fistula (Thick arrow)
Small break (thin arrow)Detached ICM(Thin Arrow)

46. Choroidal Coloboma Vs Posterior Staphyloma
Posterior Staphyloma
Choroidal Coloboma
Smooth margin
Sharp margin

47. Microphthalmos Vs Nanophthalmos
Microphthalmos
Nanophthalmos

48. PFV Vs. Vitreous incarceration(VI) Vs. ROP
PFV/ PHPV
ROP
VI

50. Silicon Oil
Elongated eyeball
•Do USG in all quadrants
• Never forget inferior &
superior quadrant to
comment

51. Emulsified Si oil (ESO) Vs. Asteroid Hyalosis(AH)
Vs. Vitreous Hemorrhage(VH) Vs. Vitreous
Cells(VC)
ESO AH
VH
VC

52. Scleral Buckle
High surface reflectivity with orbital shadowing

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

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

57. Papilleodema
Doughnut /Crescent sign
Disc elevation

58. Optic Nerve Glioma
Subtle thickening of OD w.r.to OS

59. Optic Disc Abnormalities
High gain
Low gain
Optic Disc Drusen

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)