Transcript Imaging of ocular Blood Flow

Gh.Naderian , MD
The eye has two separate and
distinct circulatory systems , the
retinal and the uveal.
The retinal vascular system
nourishes the inner retina.
The uveal system supplies the
choroid , ciliary body and iris.
Color Doppler imaging:
 Color Doppler imaging (CDI) is an
ultrasound technique combining B-Scan
gray scale imaging and blood velocity
measurements
 CDI can be used to calculate peak
systolic velocities (PSVs) and end-
diastolic velocities (EDVs) in the
retrobulbar vessels , including the
OA,CRA and nasal and temporal PCAs.
Canon laser Blood Flowmeter
 The canon laser blood flowmeter
(CLBF) is a recently developed device
used to simultaneously quantify the
velocity of blood within large retinal
vessels and their diameter.
 Use of CLBF is limited by its calculated
flow assumptions , cataract , vitreous
opacties , small pupills and eye
movement.
Heidelberg Laser Doppler
Flowmetry
 The confocal scanning laser doppler
flowmeter , also known as the Heidelberg
retina fowmeler (HRF) , combines a laser
doppler flowmeter with a confocal
scanning laser tomograph.
Scanning Laser Ophthalmoscope
Angiography
 FA and ICG angiography performed
with a scanning lascr opthalmoseope
(SLO) can be used to quantitate blood
flow.
 In SLO angiography fluorescein dye may
be used to evaluale the retinal vasculature
to yield homodynamic measurements such
as arteriovenous passage (AVP) and meam
dye velocity (MDV)
Pulsatile Ocular Blood
Flow Measurement
 Pulsatile ocular blood flow (POBF)
devices consist of a modifed
Pneumotonometer interfaced with a
microcomputer that records the ocular
pulse.
POFB monitors the rhytmic change
in intraocular pressure (IOP)
during the cardiac cycle,which
fluctuates up to 2mm Hg in
sinusoidal fashion
Clinical Applications
1) Glaucomatous optic Neuropathy
2) Diabetic Retinopathy
3) Age-related Macular degeneration