2. FA is an imaging test that highlights the retinal and
choroid circulation and is useful in the diagnosis of
retinal and choroid and optic nerve disorders,as
well as guidance during laser treatment.
3. • Outer blood–retinal barrier. The major choroidal vessels
are impermeable to both bound and free fluorescein.
However, the walls of the choriocapillaris contain
fenestrations through which unbound molecules escape
into the extravascular space, crossing Bruch membrane but
on reaching the RPE are blocked by intercellular complexes
termed tight junctions or zonula occludentes.
4. •Inner blood–retinal barrier is composed
principally of the tight junctions between
retinal capillary endothelial cells, across
which neither bound nor free fluorescein
can pass; the basement membrane and
pericytes play only a minor role in this
regard.
Disruption of the inner blood–retinal
barrier permits leakage of both bound
and free fluorescein into the
extravascular space
5. Fluorescein angiography (FA) should be performed only
if the findings are likely to influence management.
• Fluorescence is the property of certain molecules to
emit lightof a longer wavelength when stimulated by
light of a shorter wavelength. The excitation peak for
fluorescein is about 490 nm (in the blue part of the
spectrum) – the wavelength of maximal absorption of
light energy by fluorescein. Stimu- lated molecules will
emit yellow–green light of about 530 nm
• PRINCIPAL OF FFA
6.
7. Filters
• Cobalt blue excitation filter.Incident whitelight from
the camera is filtered so that blue light enters the eye,
exciting the fluorescein molecules in the retinal and
choroidal circulations.
• Yellow–green barrier filter blocks any blue light
reflected from the eye, allowing only yellow–green
emitted light to pass.
8. Fluorescein (sodium fluorescein) is an orange water-
soluble dye that, when injected intravenously,
remains largely intra- vascular (>70% bound to serum
proteins). It is excreted in the urine over 24–36 hours.
Fluorescein dye
9. Procedure
Informed consent - explain the procedure to the
patient
• Dilate patient's pupil.
• Fluorescein solution, scalp vein needle, 5 ml
syringe and the emergency tray is prepared
• Check fundus camera for any fault.
• Observe lens and fundus camera for any dust
or opacity
• Feed the machine with patientinformation -
Name, MRD no, age, sex, clinical diagnosis etc.
Insert the scalp-vein needle, preferably at anticubital
vein and inject the fluorescein dye 3ml of20% or 5 ml of
10% solution in 5-10 seconds.
10. • Oral administration at a dose of 30 mg/kg is an
alternative if venous access cannot be obtained or is
refused; a 5 ml vial of 10% (100 mg/ml) sodium.
fluorescein contains 500 mg, and pictures should be
taken over 20-60 minutes following ingestion.
• Images are taken at 1-2 second intervals initially
to capture the critical early transit phases,
beginning 5-10 seconds after injection, tapering
frequency through subsequent phases.
• Images may be captured as late as 10-20 minute
11.
12. Fluorescein allergy in past. -
Absolute contraindication
• H/O sevear allergic
reaction to other allergen
in past.
• Renal failure
• Pregnancy
• Asthma
• Cardiac disease
• Contraindication
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26. • . Normal fluorescein
angiogram. (A) Choroidal
phase showing patchy
choroidal filling as well as
filling of a cilioretinal artery
(different patient to the rest
of the series); (B) arte- rial
phase showing filling of the
choroid and retinal arteries;
(C) arteriovenous (capillary)
phase showing complete
arterial filling and early
laminar venous flow; (D)
early venous phase showing
marked laminar venous
flow; (E) mid-venous phase
showing almost complete
venous filling; (F) late
(recirculation) phase
showing weaker
fluorescence with staining
of the optic disc
27.
28.
29.
30.
31.
32.
33.
34. Pooling in an anatomical space occurs due to breakdown of
the outer blood–retinal barrier (RPE tight junctions):
• In the subretinal space, e.g. CSR. This is characterised by
early hyperfluorescence, which, as the responsible leak
tends to be only small , slowly increases in intensity and
area, the maximum extent remaining relatively well
defined.
• In the sub-RPE space, as in pigment epithelial
detachment . This is characterized by early hyperfluores-
cence that increases in intensity but not in size.
POOLING
44. VASCULAR FILLING DEFECTS
Retina
•occlusion or delayed perfusion
•central or branch artery occlusions
•capillary nonperfusion secondary to diabetes, vein
occlusion, radiation, etc.
•atrophy or absence of vessels or retina
•Choroid
•occlusion of large choroidal vessels or choriocapillaris
[sectoral infarct (wedge-shaped), malignant hypertension,
toxemia, lupus choroidopathy, renal diseasel
•atrophy or absence of choroidal vessels or
choriocapillaris (choroid-eremia, acute multifocal placoid
pigment epitheliopathy)
47. ICG ANGIOGRAPHY
•ICG is an infrared-based imaging technique used to
detect choroidal abnormalities and is specifically most
useful for the detection of occult, poorly defined forms of
choroidal neovas-cularization and can increase the
number of patients potentially treatable, using laser
photocoagulation.
48. Indocyanine Greend dye (ICG) properties
• Water soluble tricarbocyanine dye.
• Contain 5% sodium lodide.
• Absorption - 805nm
• Emission - 835nm
• 98% protein – binding
• excreted exclusively by the liver
• Dosage 25mg/2ml followed by 5ml bolus
saline
49. Principal of ICG
ICG fluorescence is only 1/25th that of fluo- rescein so
modern digital ICGA uses high-sensitivity video-
angiographic image capture by means of an appropriately
adapted camera.
Both the excitation (805 nm) and emission (835 nm) filters
are set at infrared wavelengths Alternatively.
50.
51.
52.
53.
54.
55.
56.
57.
58.
59.
60.
61.
62.
63.
64.
65.
66. "A late phase showing relative hypo Fluorescence
of the folded flap with adjacent hyperfluorescence
where the RPE is missing:
RPE tear FFA
67.
68. Occult (Type 1) choroidal neovascularization. (A)
Specks of blood at the fovea; (B-D)
FA showing diffuse hyperfluorescence but the limits
of the membrane cannot be defined:
80. Non ischemic CRVO
late phase of FA Showing masking by
blood and staining of vessel walls
(arrow) but good capillary pertusion
81. Ischaemic CRVO
. FA showing extensive
hypotluorescence due to capillary non-
perfusion
82.
83. FA showing lack of arterial filling of the involved
artery and hypofluorescence of the involved
segment due to blockage of background
fluorescence by retinal swelling;
BRAO
84. CRAO
FA showing lack of arterial filling and
hypofluorescence due to blockage of background
fluorescence by retinal swelling;
