Circulatory and Respiratory Systems. The Circulatory System.
Gh.Naderian, MD. The eye has two separate and distinct circulatory systems, the retinal and the...
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Transcript of Gh.Naderian, MD. The eye has two separate and distinct circulatory systems, the retinal and the...
Imaging of Ocular Blood FlowGh.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 Applications1) Glaucomatous optic
Neuropathy
2) Diabetic Retinopathy
3) Age-related Macular
degeneration