Download - FFA & ICG
Fundus Fluorescein Fundus Fluorescein AngiographyAngiography
PHYSICAL PRINCIPLESPHYSICAL PRINCIPLES
• Luminescence- Emission of light from any source other then high temp.
• Fluorescence- luminescence maintained only by continuous excitation. (stop as soon as exciting stimulus withdrawn)
FFAFFA
PURPOSE
• Evaluate, Diagnose -Retinal, Choroidal vascular & Macular diseases
• Guide - for laser treatment
• Monitor-effect of treatment
HISTORYHISTORY• 1871-Adolf Baeyer-first to synthesize dye
Na. Fluorescien
• 1910-Burke examine the Retina & choroid after administration of fluorescien in coffee
• 1925-Nordenson –fundus camera
• 1961-Novotny & Alvis- First Successful FFA in human.
TECHNIQUETECHNIQUE• seated in front of fundus camera
• Color & Red-free image is capture
• Fluorescein dye 5ml of 10% or 3ml 25%(for opaque media) injected.
• Images taken approx 1-sec intervals ,5-12 sec after inj.
• After transit phase photograph in one eye control picture of opposite eye.
• Flourescene enters in the eye through ophthalmic artery
• Passing into the choroidal circulation.-post ciliary A.
• Retina-central retinal a.
PHASES OF ANGIOGRAMPHASES OF ANGIOGRAM
• Choroidal (10-12 sec)
• Arterial (1-3 sec)
• A-V (capillary)
• Venous (20-25 sec)
• Recirculation(30 sec )
• Late phase(10 min)
CHOROIDAL (PRE-ARTERIAL) CHOROIDAL (PRE-ARTERIAL) PHASEPHASE
Early choroidal fluo is faint patchy & irregular-choroidal flush
• Area of filling & nonfilling distinct – patchy choroidal filling
• Cilioretinal a. fills
ARTERIAL PHASEARTERIAL PHASE
Filling of CRA.
EARLY A-V PHASEEARLY A-V PHASE• Dye from smaller venules enter
the vein along their wall-laminar flow
• Dye sticks to the wall of vein• At the junction of two
vein ,inner lamina of each merge creating a trilaminar flow
A-V PHASEA-V PHASE• Dye completely fill the lumen of vein
• Perifoveal capillary network best visualized (dye max concentration)
• Fovea appears hypofluo.
RECIRCULATION PHASERECIRCULATION PHASE
• Begins about 30 sec of dye inj
• Dye in lower concentration
LATE PHASELATE PHASE• Vessels are empty(10 min after inj)• Diffuse background fluo (d/t staining of
bruch’s memb. choroid & sclera )• Large vessels seen in silhouette against
this background• Disc remain hyperfluo in late film
(staining)
WATERSHED ZONEWATERSHED ZONE• Post ciliary a. supply the lat. & medial halves
of disc & choroid • Four (sometime 6-7) post ciliary vein (vertex
vein) drain into sup. & inf ophthalmic veins • quadrantric pattern • Segmental drainage exists vertical &
horizontal watershed• FA-patchy choroidal filling
DARK APPEARANCE OF DARK APPEARANCE OF FOVEAFOVEA
• Avascularity of FAZ
• Blockage of choroidal flurescene (xanthophyll)
• Blockage of choroidal flurescene (larger RPE , more melanin)
ABNORMAL FLUORESCENCEABNORMAL FLUORESCENCE
• d/t LEAKAGE
(a) Abnormal choro.vasculature-CNV Early lacy filling pattern
which increase in size & intensity
b)(Breakdown of inner retinal barrier-CME
• Beginning of A-V phase which increase in size and intensity
• Flower-petal pattern (late phase)
(c) Abnormal retinal or disc vasculature- PDR
HYPERFLUORENSCENCE HYPERFLUORENSCENCE D/T POOLINGD/T POOLING
• Dye in anatomical space d/t breakdown of outer retinal barrier(RPE tight jn)
(a) In the sub-retinal space-
Early hyperfluo which increase in size and intensity-CSR
CSRCSR
(b) In the sub-RPE space- PED
early hyperfluo which increases in intensity but not in size
STAININGSTAINING• Attachment of the dye molecule to tissue • May be seen in late phase of angiogram• It occur in normal structure (sclera) or pathological
states (Scar ,drusen)• Margins do not go beyond
TRANSMISSION (WINDOW) TRANSMISSION (WINDOW) DEFECTDEFECT
• Seen –focal RPE atrophy Or absence• Unmasking of normal choroidal fluo.• Early hyper-fluo. Increases in intensity & then
fades in late phase without changing size or shape
CAUSES OF CAUSES OF HYPOFLUORESCENCEHYPOFLUORESCENCE
• Reduction or absence of fluo.
(a) Blockage(masking)-retinal / choroidal
(b) Filling defects
BLOCKAGE OF RETINAL BLOCKAGE OF RETINAL FLUORESCENCEFLUORESCENCE
1-vit.opacities & Pre-retinal lesion-blood
-Block all fluo.
2 deep retinal lesions –intra-retinal h’age & HE
-Block only capillary fluo. Sparing large retinal vessels
BLOCKAGE OF CHOROIDAL BLOCKAGE OF CHOROIDAL FLUORESCENCEFLUORESCENCE
1-sub-retinal/ Sub-RPE lesion-blood
2-incease density of RPE- congenital hypertrophy of RPE
3- choroidal lesion -naevi
FILLING DEFECTSFILLING DEFECTS
1-Vascular occlusion-prevent access dye to the tissue
Occlusion may choroidal circulation / retinal a./r.vein/capillaries(capillary drop out)
2 loss of vascular bed-severe myopic deg or choroideremia