Gray scale ultrasound has been used in evaluation of the eye since late 20 century. More recently, color doppler imaging of retrobulbar vessel has been introduced as a useful adjunct to clinical examination and cross-sectional imaging for evaluating various pathologic condition in the orbit. Although gray-scale ultrasound display the anatomy of the orbit well, color doppler imaging provides additional information about the vasculature of the orbit and information regarding direction and velocity of blood flow. The color doppler changes in diabetes retinopathy has been a topic of discussion for decades and numerous studies have been conducted to study these changes. Not enough standard textbook literature is available stating these changes, but meta- analysis of studies stated a common finding of increased vascular resistance in intra orbital vessels. However, no consensus on the cut off limits of various doppler parameters for diabetic retinopathy have been reached.

1. ROLE OF ORBITAL DOPPLER IN
EVALUATION OF DIABETIC
RETINOPATHY
AUTHOR
DR. GULSHAN KUMAR
MADHPURIYA
Clinico-radiologist

2. FOLLOW OF TALKS
Gray scale
orbital
anatomy
Vascular
Anatomy
•Ophthalmic
artery
•CRA & CRV
•PCAs
•SOV
Technique
ROLE OF
DOPPLER IN
EVALUATORB
ITALION OF
DIABETIC
RETINOPATH
Y

3. INTRODUCTION
• Gray scale ultrasound has been used in evaluation of the eye since late 20
century.
• More recently, color doppler imaging of retrobulbar vessel has been
introduced as a useful adjunct to clinical examination and cross-sectional
imaging for evaluating various pathologic condition in the orbit.
• Although gray-scale ultrasound display the anatomy of the orbit well,
color doppler imaging provides additional information about the
vasculature of the orbit and information regarding direction and velocity
of blood flow.

4. ULTRASOUND ANATOMY OF ORBIT
• Anatomic structure of the eye cannot all
be identified with ultrasound
• In the anterior segment, the anterior
chamber appears as an anechoic area
limited posteriorly by the anterior capsule
of the lens. The interior of lens appear as
a an anechoic.
• And its posterior capsule is easily
recognizable.

5. ULTRASOUND ANATOMY OF ORBIT
• In the posterior segment, the vitreous appears
as an echo free cavity and posterior wall of
globe is visualised as an echogenic concave
band containing three membrane (sclera,
choroid, and retina) which cannot be
differentiated
• Retrobulbar fat is seen homogenous
hyperechoic area behind the globe, the
extraocular muscle are hypoechoic and have
a fusiform configuration.
• Optic nerve appear as a hypoechoic band in
the center of the retrobulbar fat.

6. VASCULAR ANATOMY
• Major arterial supply to the orbit is
through the Ophthalmic artery, first
intracranial branch of the internal carotid
artery,
• The major venous drainage is through the
Superior Ophthalmic vein and Inferior
Ophthalmic vein to cavernous sinus

7. OPHTHALMIC ARTERY
• Ophthalmic artery emerges through the
optic foramen in the posterior orbit just
lateral to the optic nerve.
• More anteriorly, OA usually crosses
over the optic nerve and continuous
into anteromedial orbit.

8. OPHTHALMIC ARTERY
• Branches of OA
• Central retinal
• Long and short ciliary
• Lacrimal
• Supraorbital
• Anterior and posterior ethmoidal
• Terminal branches: supratrochlear and
dorsal nasal artery

9. OPHTHALMIC ARTERY
• OA can be consistently located with
color flow imaging be scanning
medial to the optic nerve
approximately 15 posterior to the
globe.
• Waveform of the OA is typical for a
relatively high resistance artery.
There is a sharp initial peak
followed by an incisura and
relatively little flow during diastole

10. CENTRAL RETINAL ARTERY AND VEIN
• Central retinal artery and vein nourish the inner two-thirds of the retina.
• The artery and vein parallel in the center of the disc nerve and can be identified
with color flow imaging.

11. CENTRAL RETINAL ARTERY AND VEIN
• The waveform of the CRA is characteristic
of a low resistance system. It consists of a
rounded systolic peak followed by a slow
decline in velocity, with continuing
throughout diastole.
• The waveform of the CRV is obtained in
same spectrum as that of CRA. It consists
of relatively low, continuous flow in the
opposite direction relative to arterial flow.

12. POSTERIOR CILIARY ARTERIES
• PCAs supply blood to the outer
one-third of the retina, choroid
and the head of the optic nerve.
• Ultrasonographically it is
difficult to distinguish between
the short and long ciliary
arteries.

13. POSTERIOR CILIARY ARTERIES
• PCAs can be identified as vascular
structure in the posterior to the globe.
• PCAs have a waveform with a lower
system peak than that of the OA;
some flow continues throughout
diastole.
• The PCA waveform is variable,
probably due to small size of theses
vessels.

14. SUPERIOR OPHTHALMIC VEIN
• SOV can be located suoeriorly and
nasally in the orbit and identity in
about 95% of normal individuals.
• IOV is located in inferior orbit but
more difficult to locate.
• Waveform of the SOV show low
continuous flow. and can show both
cardiac and respiratory variations.

15. In order to obtain reliable measurements using
CDI, it is important to have a thorough knowledge
of the retrobulbar vascular anatomy, as well as the
characteristic waveforms of the different vessels

16. TECHNIQUE
• Equipment
• CDI uses a linear array transducer consisting of linearly
arranged, sequentially excited piezoelectric elements.
• In ultrasound, there is an inverse relation between
penetration depth and resolution. the frequency of the
Doppler probe is chosen as a compromise between
resolution and penetration depth.
• A typical transducer for retrobulbar CDI has a frequency
of 7.5 MHz, but some investigators have used up to 12.5
MHz, thereby providing better resolution but also weaker
Doppler signals.

17. TECHNIQUE
• Examination method
• Ultrasound examination of orbit is performed
through the closed eyelid with the patient
supine
• As little pressure as possible should be
exerted on the globe to avoid inaccurate
vascular recording and patient discomfort.
• Stabilizing the transducer with the fingers on
the forehead or cheek is helpful.

18. TECHNIQUE
• Precautions
• Contact lens are removed prior to the examination.
• The tip of the probe is covered with a sufficient amount of acoustic coupling gel to
provide adequate contact between the probe and the skin.
• Imaging of postoperative or traumatized eye should be performed with minimal
pressure on the globe and for the shortest possible time.

19. TECHNIQUE
The anatomy of the eye and the optic
nerve head are identified using the gray
scale images in the B-scan mode
Color Doppler is used to visualize the
flow within the vessels and allows for
identification of the appropriate vessels.

20. TECHNIQUE
The sample volume is placed in the center
of the vessel, and the angle is set parallel to
the vessel to account for the Doppler angle.
Pulse Doppler recordings can then
be obtained.
A small Doppler gate is
necessary to provide
accurate & reproductive
waveforms.

21. COMPARISON OF BLOOD FLOW VELOCITIES IN
VARIOUS STUDIES IN NORMAL INDIVIDUALS
Blood Flow Velocities in various
studies with present study in
normal individuals

22. INDICATIONS FOR COLOR DOPPLER
IMAGING
• Vascular disorders
• Cavernous-carotid and cavernous-dural fistulas
• Central retinal artery occlusion
• Central retinal vein occlusion
• Orbital ischaemia
• Ischemic optic neuropathy
• Orbital varix
• Congenital and paediatric disorders
• Congenital abnormalities of the eye
• Leukocoria evaluation
Indication for and uses of color
doppler imaging in the orbit are
still evolving.

23. INDICATIONS FOR COLOR DOPPLER
IMAGING
• Tumors
• Vascularity of lesions
• Dynamic evaluation of tumors preoperatively
• Evaluating treatment response of choroidal melanoma
• Infectious and inflammatory diseases
• Trauma
• Evaluation and follow up of hematomas
• Confirming integrity of orbital vessels

24. ROLE OF ORBITAL DOPPLER IN
EVALUATION OF DIABETIC
RETINOPATHY

25. DIABETIC RETINOPATHY
• Diabetic Retinopathy (DR) is a form of microangiopathy, and is the most
common ocular complication seen in diabetic patients these days.
• On average, Duration of 5-10 years is the time needed for this
complication to occur.
• Microangiopathy will ultimately result in retinal ischaemia.
• Retinal ischemia acts a stimulus for neovascularisation and thereby
progresses to the morbid complications like vitreous haemorrhage,
glaucoma and tractional retinal detachment.

26. DIABETIC RETINOPATHY
• Diabetic retinopathy is a vascular disorder
affecting the microvasculature of retina caused
by changes in the retinal blood vessels.
• Reduction of blood flow in central retinal artery
and short posterior ciliary arteries can be
significant in the development of diabetic
retinopathy.

29. CLASSIFICATION OF DIABETIC
RETINOPATHY
I. Non-proliferative diabetic retinopathy (NPDR)
• Mild NPDR
• Moderate NPDR
• Severe NPDR
• Very severe NPDR
II. Proliferative diabetic retinopathy (PDR)
ETDRS study classification

30. Role of color doppler in diabetic
retinopathy
• The color doppler changes in diabetes retinopathy has been a topic of discussion
for decades and numerous studies have been conducted to study these changes.
• Not enough standard textbook literature is available stating these changes, but
meta- analysis of studies stated a common finding of increased vascular
resistance in intra orbital vessels.
• However, no consensus on the cut off limits of various doppler parameters for
diabetic retinopathy have been reached.

31. OPHTHALMIC ARTERY
CDI of Normal individual showing RI value = 0.69 in
Ophthalmic artery

32. OPHTHALMIC ARTERY
Diabetic patient without retinopathy showing RI
value = 0.72 in Ophthalmic artery
Patient with diabetic retinopathy showing RI
value=0.79 in ophthalmic artery

33. CENTRAL RETINAL ARTERY
CDI of Normal individual showing RI value = 0.64 in
CRA

34. CENTRAL RETINAL ARTERY
Diabetic patient without retinopathy showing RI
value=0.73 in central retinal artery
Patient with diabetic retinopathy showing RI
value=0.80 in central retinal artery

35. POSTERIOR CILIARY ARTERIES
Diabetic patient without retinopathy showing RI
value=0.72 in short posterior ciliary arteries
Patient with diabetic retinopathy showing RI
value=0.79 in short posterior ciliary arteries

36. COLOR DOPPLER FINDINGS IN DIABETIC
PATIENTS
OPHTHALMIC
ARTERY
PSV
=/+
EDV
=↓
RI ↑
CENTRAL
RETINAL
ARTERY
PSV ↓
EDV ↓
RI ↑
POSTERIOR
CILLIARY
ARTERIES
PSV ↓
EDV ↓
RI ↑

37. • Patients with diabetes had significantly higher RI of OA, CRA & SPCAs as compared
to non-diabetic patients.
• Furthermore, the rise in RI of above mentioned vessels was significant in diabetics
without retinopathy and diabetics with retinopathy.
• Similar significant lower PSV and EDV values have been found for CRA and SPCAs
in patients developing retinopathy.
• Changes in PSV and EDV values of OA is still a matter of discussion as various
studies have stated different findings.

38. CONCLUSION
Increased RI values in Ophthalmic, Central Retinal, and
Short Posterior Ciliary arteries showed that RI value can be
used as an index to assess the progression of Diabetic
retinopathy in patients.

39. CLINICAL IMPLICATION
Hemodynamic changes can be picked up early on color doppler, as
compared to retinopathic changes.
It can provide an opportunity for early intervention in the form of
medical therapies such as anti-VEGF pharmacologic agents.
Early medical intervention could also prevent the need for
photocoagulation which is used in late severe stages of retinopathies.