ALSO known as B scan of eye good for knowing the ocular pathology when media is hazy

1. Ultrasonography
of eye
By Dr Nikita Jaiswal
2nd year resident

2. Glossary
O Introduction
O Terminologies
O Probe Positions
O Interpretations

3. Introduction
O B scan ultrasonography also known as
(brightness scan).
O It utilizes high frequency sound (10-
20Mhz) from a peizoelectric crystal
emitter/receiver that penetrates the tissue
& bounces back.

4. ULTRASOUND:
O It is an acoustic wave that consists of an
oscillation of particles within a medium.
O Ultrasound waves have frequencies greater than
20kHz(i.e. 20,000oscillations/sec).
O Ophthalmic ultrasound is in the range of 8 to 10
MHz
O 1 megahertz=10,00,000 cycles/sec

5. History
O 1956- Mundt & hughes
O 1958-Baum & greenwood
O 1960- Jansson & associates
O In 1960’s ossoing emphasized on standardised
instrumentation ophthalmologist

7. During examination, the following systematic approach
is
universally recommended:
1. Screening for lesion detection: A+ Bscan.
2. Topographic examination for shape, border, location and
extension (if possible) of the lesion: Bscan.
3. Quantitative Echography to know the reflectivity, sound
attenuation & internal structure of lesion. It helps in
determining the texture of the lesion: Ascan.
4. Kinetic echography provides information about the
mobility, aftermovement and vascularity (Valsalva
manoeuvre) on Bscan. It also includes colour Doppler
assessment for blood flow.

9. Ultrasound Frequency
Abdominal 2-5 MHz
B scan 10 MHz
UBM 20-50 MHz

10. Media speed
cornea 1641 m/s
Aqueous humor 1532 m/s
lens 1641 m/s
Vitreous humor 1532 m/s
Silicone oil 990 m/s

11. INDICATIONS:-
O 1.Evaluation of intraocular details obscured
from visualization
by the ocular media opacities.
O 2. Evaluation of retinochoroidal lesions
especially tumors even
with clear media.

12. 3. Differentiation of solid from cystic and
homogenous from
heterogeneous masses.
4. Examination of retrobulbar soft tissue masses and
normally
present orbital structures (to differentiate proptosis
from
exophthalmos).
5. Identification, localization and measurement of
non radioopaque/
radio-opaque foreign bodies. Assessment of
collateral damage in trauma cases.
6. Biometry .
7. Follow up evaluations

13. Terminologies
O Reflectivity: sound which is emitted by the
probe gets reflected back at the interface
between two media
O Ex: Aqueous & lens, vitreous & retina
forms an echo.
The greater the diff in density between the
structures, the greater will be its echo.

14. ANGLE OF INCIDENCE: the probe must always be placed
perpendicular to the area of interest to receive greater amount of
signals preventing dissipation.
ABSORPTION: when the ultrasonic waves encounter a dense
medium.,part of its gets reflected & part of it gets absorbed ,greater
the density greater will be absorption.
GAIN: It does not alter the frequency of sound or its velocity but
only changes the display pattern on the screen.
HIGHER GAIN=weaker signal gets dispalyed
LOW GAIN=only the structures with higher reflectivity gets
displayed.

15. PROBE POSITIONING:
O Transverse
O Longitudinal
O Axial

16. PROBE:
O It has a transducer that moves rapidly back &
forth near the tip.
O Tip of the probe is oval in shape.
O Each probe has a marker.
O Methylcellulose is used as the coupling agent.
O Place to be placed: conjunctiva /cornea
O Over the eyelids it can be placed but avoided.

18. Bscan probes are thick, with a mark and emit
focussed sound beam at a frequency of 10MHz. Pictures obtained
with Bscan probe are two dimensional as compared to Ascan
probe.
The mark on the Bscan probe indicates beam orientation so that
the
area towards which the mark is directed appears at the top of the
echogram on display screen. Bscan probe can also be put directly
on
the anaesthetized globe after applying eye speculum; but mostly
the
Bscanning is done transpalpebrum with slightly increased overall
gain.

21. PROBE ORIENTATIONS:
O Transverse
O Longitudinal
O Axial

22. TRANSVERSE
Transverse section: The mark is kept parallel to
the limbus and probe
is shifted from limbus to the fornix and
also sideways. This scan gives
the lateral extent of the lesion

26. Longitudinal section: The mark is kept at right angle to the limbus to
determine the antero-posterior limit of the lesion.

29. Axial section: The patient fixates in the primary
gaze and the probe is
placed on the globe and directed axially. Depending on
the clock hour
location of the marker, axial-horizontal, axial-vertical
and axial oblique
pictures are obtained. These sections demonstrate
lesions at
the posterior pole and the optic nerve head.

31. 3-Limbus 9-Posterior
3-Equator 9-Equator
3-Fornix 9-Anterior
6-Limbus 12-Posterior
6-Equator 12-Equator
6-Fornix 12-Anterior
Probe position Area screened

32. INDICATIONS:
O MEDIA OPACITY:
LID ODEMA
CORNEAL OPACITY
KERATO PROSTHESIS
HYPHAEMA
HYPOPYON
SMALL PUPIL
PUPILLARY MEMBRANE
DENSE CATARACT
DENSE VITREOUS HAEMORHAGE
DENSE VITREOUS EXUDATES.

33. OTHERS:
O Differentiation of serous/haemorrhagic choroidal
detachment.
O Differentiation of rhegmatogenous/exudative
retinal detachment.
O Differentiation of iris from a ciliary body lesions.
O Differentiation of intraocular tumors.

34. Evaluation:
O Vitreous
O Retina
O Choroid
O Optic nerve

43. S/O OF PVD

46. POSTERIOR STAPHYLOMA

47. CHOROIDAL COLOBOMA WITH RETINAL
DETACHMENT

48. POST. DROPPED NUCLEUS

49. OPTIC DISC DRUSEN

50. Cystecercosis with retinal tear

51. Post dislocated IOL.

52. Calcified retinoblastoma

53. Air in the antetrior
chamber

55. THANK YOU