3. FLUORESCENCE
– FLUORESCENCE is luminescence that is maintained only by
continuous excitation.
– Emission stops when excitation stops.
– Excitation at one wavelength occurs and is emitted
immediately through a longer wavelength.
6. PSEUDOFLUORESCENCE
– Occurs when non-fluorescent light passes through entire
filter system
– It causes non-fluorescent structures to appear fluorescent
– Thus excitation (blue) and barrier (green-yellow) filters
should be matched to avoid overlap of light between them
8. Sodium fluorescein
➢An organic vegetable dye.
➢Orange – red, crystalline hydrocarbon (C20-H12-O5-Na)
➢Molecular weight - 376 Dalton
➢Excited between 465-490 nm & fluoresces at 520-530 nm.
➢Does not diffuses out through outer and inner blood retinal barrier
➢It diffuses through choriocapillary and Bruchs membrane
➢Eliminated by liver and kidneys within 24 hours
9. – Non expensive, non toxic , highly fluorescent that can be
used safely with most people.
– It fluoresces effectively at normal blood ph level(7.37-7.45)
– 80% bound to plasma protein and also with RBC
– High solubility in water.
advantage- can’t pass through tight retinal barriers so
allows study of retinal circulation
disadvantage- can’t study choroidal circulation
11. Indocyanin
Green
– Green dye that fluoresces with invisible infrared light.
– It specially useful for studying the deeper choroidal
circulation.
– Safe for general use and less toxic than sodium flourescein.
– Needs special type of fundus camera.
12. Purpose of
FFA
– studying the normal physiology of the retinal and choroidal
circulation,as well as disease process affecting the macula.
– Evaluation of the vascular integrity of the retinal and choroidal
vessels
– Check the integrity of the blood ocular barrier.
outer blood retinal barrier breaks in CSR
inner blood retinal barrier breaks in NVD , NVE
15. CONTRAINDICATIONS
ABSOLUTE
1) known allergy to iodine containing compounds.
2) H/O adverse reaction to FFA in the past.
RELATIVE
1) Asthma
2) Hay fever
3) Renal failure
4) Hepatic failure
5) Pregnancy ( especially 1sttrimester)
16. TECHNIQUE
- Informed consent
- Dilate pupils
- Prepare fluorescein solution, scalp vein cannula & syringe
- Prepare the fundus camera i.e. clean the front lens, focusing
of eyepiece crosshairs
- Position patient for comfort, alignment and focus
- Align and focus camera
17. - Take colour photographs
- Take red-free photographs
- Insert scalp vein cannula
- Inject dye as bolus and start timer
- Shoot exactly at start and exactly at finish of injection
- Again start shooting at 8 sec. in young and 12 sec. in adults
after injection, at interval of 1-2 sec.
- Shoot late pictures at 5 min. and 10 min.
18. Circulation of NAF
Dye injected from peripheral vein
venous circulation
heart
arterial system
INTERNAL CAROTID ARTERY
Ophthalmic artery
Short posterior ciliary artery)
(choroidal circulation.)
Central retinal artery
( retinal circulation)
- The choroidal filling is 1 second prior to the retinal filling.
19.
20. Terminologies
– Fluorescence- ability of a compound to absorb light of
shorter wavelength and emit light of longer
wavelength with in a very short interval
–
–
– Hyperfluorescence – an area of abnormally high
fluorescence due to increase density of dye molecule
Hypofluorescence - an area of abnormally poor
fluorescence
Autofluorescence – an inherent property of a lesion
to spontaneously fluoresce even in absence of dye
( observed before injection of the dye)
21. – Control photograph –photo taken before dye given
to detect autofluorescence
– Arm retina circulation time- from dye injection to first
appearance in retinal arteries( 10-12 secs)
– Pooling- accumulation of dye in closed space .e.g. RPE
detachment, CSR
– Leakage- dye escapes in open space e.g. vitreous
space
– Window defect- type of early hyperfluorescence due
to RPE atrophy
22. – Staining- late hyperfluorescence due to adsorption of
the dye by a tissue
– Blocked fluorescence – hypofluorescence occurs by
masking underlying retinal and choroidal tissue by
blood , pigment etc.
– Capillary nonperfusion – due to non filling of the
retinal capillaries due to anatomical and function
reasons
– Artifacts- undesirable shadows that are seen
following the development of the film
25. Consists of the following overlapping phases
- Choroidal phase
- Arterial phase
- Arterial venous (capillary) phase
- Venous phase
- Early phase
- Mid phase
- Late phase
– -Late elimination phase
Normal Fluorescein Angiogram
26.
27. Choroidal
Phase
– 10 -12 seconds after dye injected
– Initially patchy filling followed by the diffuse filling as the dye leaks
from the choriocapillaries.
– No dye has reached the retinal arteries.
– Cilioretinal artery if present fills in this phase
34. Late phase
( Elimination
phase)
• Gradual elimination of dye from the choroidal and retinal circulation.
– Staining of the disc is the normal finding.
– Any areas of late hyper fluorescence suggest an abnormality
• .Fluorescence is absent from angiogram after 5-10 minutes and is
usually totally eliminated from the body within several hours
36. Hyperfluorescence
➢Window defect- focal RPE atrophy
Unmasking of normal background of choroidal fluorescence
characterized by early hyperfluorescence which increases in
intensity then fade without changing shape and size
e.g. APMPPE, Serpiginous Choroiditis
inflammation of RPE
depigmentation and atrophy of RPE
38. Pooling
Pooling ( accumulation of dye in a closed space)
sub-retinal space
-Early hyperfluorescence
-increase in size ,intensity
e.g. CSR
sub RPE space
early hyperfluorescence
increase intensity only
e.g. PED
44. ➢Leakage ( frank hyperfluorescence
that increase in size and intensity )
1) Abnormal choroidal vasculature
CNV
2) Breaking of inner blood-retinal barrier
Cystoid macular edema- flower Patel
3) Abnormal retinal or disc vasculature
NVD, NVE
➢Staining ( hyperfluorescence that is minimum in early and
mid phase and increasing in late phase)
Due to prolonged dye retention e.g. drusen
45. Causes of hyperfluorescence
Leakage of dye Prolonged dye retention
( staining)
Into sensory retina From new vessels
(Cystoid macular edema) (choroidal neovascularization)
Associated with drusen
55. •
•
Macula appears relatively normal
dark blot hemorrhage
• Capillary non-perfusion on FA
• Enlargement of the FAZ
FILLING DEFECT
Diabetic macular ischemia
60. Limitations of FFA
1) Does not permit study of choroidal circulation details due to
a) melanin in RPE
b) low mol wt of fluorescein
how to overcome… . I C G
2) More adverse reaction
3) Inability to obtain angiogram in patient with excess hemoglobin or
serum protein.e.g.
polycythemia
weldenstrom macroglobulenaemia
binding of fluorescein with excess Hb or protein
Lack of freely circulating molecule
61. autofluorescence
– Innate property of fluorescein in certain ocular tissue
– Fluorescein without dye
– It is exhibited by
– Crystalline lens, basement membrane, myelinated nerve
fibers, melanin granules ,certain lipids
63. Stepwise approach to reporting
FFA
1) Comment on red free photograph
2) Is the abnormality black or white?
3) Indicate the phase of angiogram
4) Indicate any characteristic feature as smoke stag
5) Are the retinal vessels filling normally?
6) Indicate any change in area or intensity of
fluorescence
N.B : patient’s history and clinical co relation should always be
done before drawing conclusion from the FFA
64. Stepwise approach to reporting FFA
Patient’s history and clinical co relation should always be done before
drawing conclusion from the FFA
• Comment on red free photograph
• Is the abnormality black or white
• Indicate the phase of angiogram
• Indicate any characteristic feature
• Are the retinal vessels filling normally?
• Indicate any change in area or intensity of fluorescence
