1.  NALIN NAYAN
 OPTOMETRIST

2.  It is a medical imaging technique used to visualize the
inside of blood vessels and organs of the body, with
particular interest in the arteries, veins and the heart
chambers.
 traditionally done by injecting a radio-opaque contrast
agent into the blood vessel and imaging using X-ray
based techniques
 The word itself comes from the Greek words angeion,
"vessel", and graphein, "to write or record".
 The film or image of the blood vessels is called an
angiograph, or more commonly, an angiogram.

3. - Fundus Fluorescein angiography refers
to photographing fluroscein dye in the
retinal vasculature following intravenous
injection of fluroscein sodium.
- Described in 1959 by MacLean and
Maumenee

4.  Fluorescein (C20H12O5)
refers to Fluorescein
sodium (C20H10Na2).
 Is a brown or orange-red
crystalline substance first
synthesized in 1871 in
Germany by Von Baeyer

5.  1882 – Ehrlich introduced Fluorescein into
investigative ophthalmology
 1940 – Gifford studied aqueous dynamics after
injecting intravenous Fluorescein
 1960 – 2 medical students Novotny & Alwis
experimented on each other and developed
FFA

6.  Non toxic, inexpensive, safe
 Alkaline solution
 Highly fluorescent
 Absorbs blue light (480-500 nm)
 Emits yellow-green (500-600 nm [525
nm])
 Effective at pH 7.37-7.45
 Removal from blood by kidneys and liver
within 5 hrs.

7.  Inner and Outer blood retinal barriers
control movement of fluid, ions &
electrolytes from intravascular space to
extracellular space in retina
 FFA – method of examining competence
of blood retinal barriers and making
permanent record

8.  GENERAL PRINCIPLES:-
-Fluorescein binding.
-Inner blood retinal barrier.
-Major choroidal vessels.
-Outer blood retinal barrier.
-Excitation peak.
-Types of filters.

9.  70-85% fluorescein molecules bind to
serum proteins (mainly albumin) on
entering the circulation.
 The rest unbound molecules are referred
to as free fluorescein.

10.  At level of retinal capillary endothelium (tight
junctions, non-fenestrated) and basement
membrane
 Prevents all leaks of free fluorescein and
albumin-bound fluorescein.
 in vascular permeability caused by changes in
intravascular pressure or tissue hydrostatic
pressure, or by change in capillary walls
themselves, will permit leakage of both bound &
free fluorescein molecules in extra vascular
space.

11. -impermeable to both bound & free
fluorescein molecules.
- walls of choricapillaries are extremely
thin & contain multiple fenestrations
through which free fluorescein molecules
are able to escape into the extra vascular
space & across Bruch’s membrane.

12.  Composed of intact RPE (tight junctions
b/w RPE cells).
 Impermeable to free fluorescein.
 RPE presents an optical barrier to
fluorescein and masks choroidal
circulation

13.  490 nm (blue part of spectrum).
 represents maximal absorption of light
energy by fluorescein.
 Molecules stimulated by this wavelength
will be excited to higher energy level &
will emit light of longer wavelength
( green portion of spectrum i.e. at 530 nm
).

14.  2 types of filters:-
- cobalt-blue excitation.
- yellow-green barrier.
Ensures blue light enters the eye & only
yellow green light enters the camera.

15.  Light emitted from retinal camera passes
through blue excitation filter, emerging
blue light enters the eye & excites
Fluorescein molecules in retinal & choroid
circulation of longer wavelength (yellow
green).
 Yellow green barrier filter thus blocks any
blue light that may leave eye, allowing only
yellow-green light to pass through
unimpaired to be recorded on film.

16. - Pupil should be dilated.
TECHNIQUE:-
- Patient seated in front of camera with one arm
out stretched.
- Fluorescein 5 ml of 10% solution is drawn up
into syringe.
In opaque media, 3 ml of 25% solution may be
preferred, because it gives better result.

17. - Red free photograph is taken.
- Fluorescein injected rapidly into antecubital
vein.
- Photographs are taken at approx 1 sec interval
between 5 & 25 sec after injection.
- After transit phase has been photographed in
eye, control pictures are taken of opposite eye.
If necessary, late photograph can also be
taken after 10 min & occasionally after 20 min if
leakage is anticipated.

18.  Red after image.
 Transient nausea.
 Flushing of skin.
 Itching.
 Hives.
 Excessive sneezing.
 Discolouration of urine & skin.

19.  Baseline photos and red free
 5 Phases of FFA
 Choroidal phase
 Arterial phase
 Capillary phase
 Venous phase
 Late phase

20. 1) CHOROIDAL OR PRE-ARTERIAL PHASE:-
-Choroidal circulation is filling, but no dye has
reached the retinal arteries.
2) ARTERIAL PHASE:-
-follows 1 sec after pre-arterial phase.
-extends from first appearance of dye in the
arteries until whole arterial circulation is filled.
3)CAPILLARY OR ARTERIOVENOUS PHASE:-
-characterized by complete filling of the arteries
& capillaries with early lamellar flow in the
veins.

21. 4) VENOUS PHASE:-
- subdivided into early, mid & late stages according to
extent of venous filling & arterial emptying.
early venous phase:- shows complete arterial & capillary
filling, & lamellar venous flow.
mid venous phase:- shows almost complete venous filling.
late venous phase:- shows complete venous filling.
-arteries are beginning to show decreasing
fluorescence.
-Recirculation of dye occurs within 3-5 min.
-The intensity of fluorescence begins to diminish so
that arteries & veins appear equally fluorescent.

22. 5) LATE PHASES:-
- shows effects of continuous recirculation,
dilution & elimination of dye.
- with each succeeding wave, the intensity
of fluorescence becomes weaker.
- late staining of optic nerve is a normal
finding.

23.  Arm to retina (ONH) 7-12s
 Posterior- ciliary artery fill 9s
 Choroidal flush, cilio-retinal artery 10s
 Retinal arterial phase 10-12s
 Capillary transition phase 13s
 Early venous/lamellar/a-v phase 14-15s
 Venous phase 16-17s
 Late venous phase 18-20s
 Late phase 5 – 15 mins

24. 12s arterial phase 15s early venous
20s venous phase 52s late phase

25.  Arterial phase may range from 2-30s;
 may be affected by:
- cardiac disease
- blood viscosity
- vessel calibre
- CCF
- GCA
- BP↑
- carotid artery stenosis.

26.  Superior arterioles fill before inferior and
temporal before nasal
 Choroidal & scleral fluorescence depends on
pigment density of RPE & its integrity
 Macular hypo fluorescence – due to ’d density↑
of RPE & xanthophyll blocking choroidal
fluorescence
 No retinal capillaries – FAZ 500μm; foveola
350μm

27.  Only 2 fundamental principles in FFA
- HYPER fluorescence or
HYPO fluorescence !

28.  MAY BE CAUSED BY:-
1) AN RPE WINDOW DEFECT:
-RESULTING FROM ATROPHY OF
OVERLYING RPE CELLS WITH
UNMASKING OF NORMAL
BACKGROUND CHOROIDAL
FLUORESCENCE.

29. 2) POOLING OF DYE:-
-UNDER A DETACHMENT OF RPE OR IN
IN THE SUB RETINAL SPACE.
- CAUSED BY A BREAKDOWN OF
OUTER BLOOD RETINAL BARRIER.

30. 3) LEAKAGE OF DYE:-
- into the sensory retina as a result of
breakdown of inner blood retinal barrier.
- may be:-
~from choroidal new vessels.
~from retinal new vessels.
~from the optic nerve head
(in papilloedema).

31. 4) STAINING OF TISSUES:-
- as a result of prolonged retention of
fluorescence.

32.  Permeability defects cause pooling &
staining
 Pooling – serous RPE detachment, SRF (↑
in size, shape & intensity in later phases)
 Staining – sclera, ON, drusen, vasculitis.
(Leak into tissue rather than anatomical space)

33.  May be caused by :-
1) BLOCKAGE OF FLUORESCENCE:-
- by increased density of pigment
(xanthophyll -sensory retina,
melanin- RPE)
- deposition of abnormal materials
( hard exudates in sensory retina,
lipofuscin in Best’s disease)
- Blood.

34. 2)obstruction of retinal and choroidal
circulation:-
- preventing access of fluorescein to the
tissues.
3) loss of vascular tissues:-
- in severe myopic degeneration or
choroideremia.

35.  Due to the 2 barrier filters not having
mutually exclusive transmission spectra
 Light from bright fundal structures can
pass through both filters & expose film.
e.g. ONH drusen, astrocytic hamartomas

36.  Autofluorescence can
be diagnostic
 FFA can exclude
papilloedema
 Saves pt from
invasive neuro
diagnostic
procedures!
Optic nerve head drusen

37.  CB readily leaks fluorescein during
aqueous production, into ocular fluids.
 Green light emitted when excited by
blue light. Illuminates light coloured
structures eg: MNF’s, white lesions

38.  To aid diagnosis
 Decisions on whether to Rx or not
 Always study FFA’s with other relevant
investigations before making final
diagnosis

39.  Start by describing obvious abnormality
 Describe hypo/hyperfluorescent
components
 Intensity of fluorescence with time
 Area of fluorescence & changes with time

40.  Run through anatomical list describing
any other abnormalities affecting
structures below:
 Macula
 Disc
 Major arcades
 Capillaries

41.  Early venous phase
 HyperF – NVD, ma’s
 HypoF – blocked due
to blood

42.  HypoF retinal
haem 1 ischaemia 2
 HyperF ma’s 3, nv’s 4
 IRMA 5
 Venous beading 6

43.  HyperF – ma’s (leak)
& laser spots (stain)
 HypoF – pigmented
scars, blood,
capillary drop out

44.  HypoF – massive
retinal capillary
dropout, pigmented
laser scars
 HyperF – laser scar
staining

45.  HypoF – retinal
capillary closure, SRF,
blood
 HyperF – retinal vein
damage – staining
collagen, leaking
through damaged
endothelial walls

46.  HyperF – damaged
veins staining and
leaking, ma’s
 HypoF – subretinal
and preretinal haems

47.  Collaterals don’t
leak!

48.  Non-perfusion of retinal
vasculature.Vessels appear
dark against light background
 No capillary perfusion, so
empty veins (cattle-trucking)
 Choroidal perfusion intact
(hence “cherry red spot”); C-
R artery sparing in 15%

49.  RPE atrophy allows
choroidal fluorescence
through with choroidal
“flush”
 Does not change size or
shape with time
 Fades with choroidal
fluorescence
Red Free
Late

50.  Large area of GA
 Clear view of
choroidal vessels
 FFA shows
unmasking of
choroidal vessels

51.  RPE “show-through”
 Loss of masking
 Early lighting up with
choroid

52.  Small defect in outer
BR barrier
 F enters RPE defect &
fills serous retinal
elevation “blister” (7%
cases)
 HyperF - ’s in size &↑
intensity
Early
Late

53.  Breakdown of internal BR
barrier
 Early leak from
parafoveal retinal vessels
– hyperF, in FAZ↓
 Late pooling in classic
“petalloid” appearance
(NFL)

54.  Ischaemia & vasculitis
incompetent endothelial
TJ’s
 F leaks into CT of bv’s &
stains it.This persists
 Late disc staining is
normal
ARN
Pars planitis

55.  Early lacey hyperF
“classic”
 HypoF “halo” – blood
&/or macula pigment
 Late leak, blurred
margins & apparent ↑
in size

56.  Type I – PED – well-
defined area of early
hyperF, margins
unchanged
 Type II – late leak of
undeyermined
source – not obvious
from early phase

57. Choroidal naevus blocking choroidal fluorescence in arterial phase

58.  Stargardt’s – “dark
choroid” (early)
 Lipofuscin deposition
at RPE

59.  Fluorescein Angiography, technique
interpretation & application, Max
Nanjiani (OMP)
 www.mrcophth.com/ffainterpretation