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FFA
• technique for examining the circulation of
the retina and choroid using a fluorescent
dye and a specialized camera.
Purpose
• Highlight retinal and choroidal circulation
• Detect early vascular pathologies
• Confirm diagnosis
How does it work?
Charateristics applications
• Absorbs 465-490nm,
emits 520-530nm
• Binding to plasma
proteins, esp Albumin
• Selective visualization of
its passage
• Confined to natural blood
retinal barrier
• Based on luminescence.
– Fluorescence
– phosphorescence
• Exciter filter
– Allows only blue light to illuminate
retina(wavelength of 490 nm)
• Barrier filter
– Allows only yellow-green light (from the
fluorescence) to reach the camera
wavelength 525 nm)
P
Dosage and Administration
• It is performed by injecting fluorescein
sodium dye as a bolus into a peripheral
vein. The normal adult dosage is 500mg,
and is typically packaged in doses of 5 ml
of 10% or 2 ml of 25%.
The sequence:
passage of dye after inj.Visualization
• 10 to 15 sec : Short posterior ciliary arteries.
• Choroidal flush, optic nerve head, cilioretinal
artery.
• 11-18 sec: Retinal circulatiion, arteries-capillaries-
veins.
• 20-25 sec: juxtrafoveal and perifoveal capillaries
Maximal fluorescence around FAZ. The best time
for PEAK PHASE IMAGING.
• 30 sec: First passage completed. Recirculation
starts
• After 10min: total disappearance of dye.
• A. (preinjection) With exciter and barrier in place, the
featureless black control photograph reveals either
the presence or absence of auto- and
pseudofluorescence.
• B. (0 secs after injection) The tran-sit phase begins
with choroidal filling.
• C. (10 secs) Described as patchy, the transit phase is
simultaneous with the filling of cilio-retinal arteries
• D. (12 secs) The retinal arteries are infused.
• E. (15 secs) The dye returns via the retinal
veins. Note the laminar flow during the
arteriovenous phase
• F. (about 30 secs) The angiogram is brightest
and microvasculature most visible.
• G–I. (5 and 10 mins) As the fluorescein
dye diffuses through the tissue, contrast
decreases and the optic nerve head stain
The Interpretation
Hypo-fluorescenceHyper-fluorescence
• Blocked: Media opacity,
Hem
• Vascular Filling Defects:
Occlusions, capillary non
perfusion
• Autofluorescence
• Transmitted fluorescence
• Hyperfluorescence:
• 1. Abnormal Vessels:
Angiomas, Tumours
• 2. Leakage:
• 3. Pooling: CSR, PED
• 4. Staining: Disc, drusen,
chorioret. scar
Macular degeneration
• (A) Color
• (B) red-free
• (C) photgraphs of a fundus with soft drusen and hyperpigmentation. Soft drusenhyperfluoresce during the early phase of angiography (D)stain in the late phase
choroiditis
• Red-free photo, early
arteriovenous phase, peak phase ,
and late phase angiogram of a left
eye with choroiditis. Early
angiogram demonstrates
hypofluorescence of the choroidal
lesions with the development of
circumferential hyperfluorescence
and leakage in the later stages of
the angiogram.
Central Serous
retinopathy
Color fundus photograph
(A) and corresponding
fluorescein angiography
images,
(B) early, (C) mid, (D) late
phase
showing ink blot type of
RPE leak
• Fluorescein angiogram showing intense hyperfluorescence created by the window defect after a retinal pigment epithelial tear. The hypofluorescence corresponds to the area where the pigment epithelium rolled together in accordion fashion
BRVO
Late arteriovenous phase
demonstrates leakage from the
supertemporal retinal vessels
Late arteriovenous or laminar
venous phase angiogram in a
patient with a superotemporal
branch retinal vein occlusion.
Hypofluorescence is noted along
the superotemporal arcade
Be aware-
• nausea, vomiting, acute hypotension, anaphylaxis
• Cardiac arrest
• Death
• The most common adverse reaction is nausea, due to a difference in the pH
• 25 times higher if the person has had a prior adverse reaction
• The risk can be reduced with prior (prophylactic) use of antihistamines
• Premedication with promethazine
hydrochloride or proclorperazine may
prevent or lessen the severity of nausea
and vomiting in patients with a history of
previous reactions to fluorescein
• Extravasation
• pruritus or urticaria can be treated with
antihistamines
• More severe reactions are rare, but
include laryngeal edema, bronchospasm,
anaphylaxis, tonic-clonic seizure,
myocardial infarction and cardiac arrest.
The overall risk of death from fluorescein
angiography has been reported as 1 in
222,000.
Yannuzzi LA, Rohrer KT, Tindel LJ, et al. Fluorescein angiography complication survey. Ophthalmology 93:611-617, 1986.
During Pregnancy and
Lactation
• Controversial
• Fl. Crosses the placenta
• Has been done in pregnancy with no adverse effect
• Do it when necessary