Indocyanine green (ICG) videoangiography provides high-resolution imaging of the choroidal vasculature. It has several advantages over fluorescein angiography, including better visualization through pigmented tissues. ICG is protein-bound, allowing enhanced imaging of the choroidal vasculature. Clinical applications include imaging choroidal neovascularization, polypoidal choroidal vasculopathy, central serous chorioretinopathy, and inflammatory choroidal diseases. ICG angiography aids diagnosis and management for these conditions by delineating vascular patterns and lesion activity not visible on fluorescein angiography.

1. INDOCYANINE GREEN
VIDEOANGIOGRAPHY
Moderator: DR. AJAY R KAMATH
Presenter :DR. POOJA

2. • INTRODUCTION
• SPECIAL PROPERTIES
• ADVANTAGES
• TECHNIQUE
• CLINICAL APPLICATIONS

3. INTRODUCTION
• 1957-Its first application in measuring CARDIAC OUTPUT
• 1970-Kogure et al. reported on intra-arterial ICG absorption of
the choroid in monkeys.
• 1972-Flower and Hochheimer performed the first IV ICG
angiography to image the human choroid.
• 1980-Hayashi and co-workers developed improved filter
combination with sufficient sensitivity for near-infrared
wavelength.

4. • 1989-Scheider and Schroedel introduced the use of
scanning laser ophthalmoscope.
• 1992-Guyer introduced 1024 x 1024 line digital imaging
system to produce high-resolution ICGA.
• Yannuzzi and co-workers described a 1024-line resolution
system which was synthesized with appropriate flash
synchronization and image storage capability ,permitting
high-resolution ,long duration ICGA

5. SPECIAL PROPERTIES of ICG
CHEMICAL PROPERTIES:
• Sterile, water-soluble tricarbocyanine dye
• Empirical formula-C43H47N2NaO6S2
• Both lipophilic and hydrophilic
• Na I is incorporated to create an ICG lyophilisate which
can be dissolved in water.

6. OPTICAL PROPERTIES :
• Absorption spectrum -790 to 805 nm
• Emission spectrum -770 to 880 nm(835nm)
• RPE and Choroid absorbs 59-75% of blue green light
used in FA ,but 21-38% of near infrared light used in
ICGA
• Better visualization through
Serosanguinous fluid
Shallow haemorrhage
Pigment and lipid exudate

7. PHARMACOKINETICS :
• 98% protein bound(80% to globulins)
• Less dye escapes from the fenestrated choroidal
vasculature allowing enhanced imaging
• Excreted by Liver
• Not detected in Kidneys, Lungs, CSF and does not
cross Placenta

8. TOXICITY :
• Relatively safe drug
• Adverse affects are less common than NaF
• Mild reactions are Nausea Vomiting and Pruritus (0.15%)
• Should be used with caution in patients with iodine allergy
• Avoided in Uremic and liver disease patients
• Classified as Cat-C drug for pregnant women

9. Advantages over FFA
• Study of choroidal vasculature otherwise prevented in FFA
due to RPE blockage
• Near-infrared light utilized penetrates melanin, xanthophylls,
exudates and sub-retinal blood.
• Infrared is scattered less than visible light, thus suitable in
eyes with media opacities
• 98% ICG molecules bound to protein, thus remaining in the
blood vessels.

10. TECHNIQUE
• ICG should be dissolved in aqueous solvent and used within
10 hrs after preparation. Std.conc :25mg in 5ml
solvent.(50mg,75mg)
• Rapid IV injection is followed by 5ml saline flush.
• Images captured in 1min intervals till 5min,10-15min intervals
for 30-40 min
• New TECHNIQUES :
Real-time ICGA(30 frames/sec)
Wide angle ICGA(160o of field )
Digital subtraction ICGA
High-speed angiography

11. PHASES OF ICGA
• Early phase (first 60 sec post
injection) :choroidal arteries
• Early mid phase (1-3 min) :
choroidal veins and retinal vessels
• Late mid phase (3-15 min) :
choroidal vessels fading but
retinal vessels are still visible
• Late phase (14-45 min) :
hypofluorescent choroidal vessels
and gradual fading of diffuse
hyperfluorescence

12. CLINICAL APPLICATIONS
• ARMD
• Idiopathic Polypoidal Choroidal Vasculopathy
• Central Serous Chorioretinopathy
• Choroidal Inflammatory disease
Multiple Evanescent white dot syndrome
Serpiginous Choroidopathy
• Choroidal Tumours

13. ARMD
• Hayashi and associates found that ICG videoangiography was
useful in detection of CNV,it revealed a well-defined
neovascularization with occult CNV by FA.
• They also were the first to show that the leakage of ICG was
slow compared to sodium fluorescein.
• Yannuzzi et al and Guyer et al studied ICGA of AMD patients
and grouped them as follows
Depending on SIZE and DELINEATION
“HOT SPOT” “PLAQUE”
Well defined Poorly defined Combination

14. • Macular Photocoagulation Study recognized two forms of
OCCULT CNV:
(1) a fibrovascular pigment epithelial detachment (PED)
(2) a late-phase leakage of an undetermined source (LLUS)
A pigment epithelium detachment (PED) (A, fluorescein angiography) with a well-delineated neovascular
network located along the edges of the PED (B, indocyanine green angiography).

15. Fibrovascular pigment epithelium detachment (PED). FA demonstrates occult choroidal neovascularization with PED (A). In
the early phases of (ICGA) a feeder vessel originating in the juxtapapillary area is clearly delineated (B, asterisk).

16. Late leakage of undetermined source (A, C). Indocyanine green angiography may clearly differentiate
a subtype of occult choroidal neovascularization (B) from retinal angiomatous proliferation (D).

17. Advantages of ICG in CLASSIC CNV
• ICGA improves visualization of the fine
structure of the neovascular network allowing the
choroidal and retinal circulation to be
distinguished.
• In patients with chronic AMD or those who
did not benefit from previous treatments with
anti-VEGF, ICGA might better delineate a more
mature stage of CNV. This has potential
implications for therapeutic decision-making.

18. In FA image (A), the leakage of the dye from the lesion is evident, and obscures the boundaries of the
neovascular network. (ICGA) (B), the limits of the neovascularization are much more visible

19. POLYPOIDAL CHOROIDAL VASCULOPATHY
(PCV)
• It is a primary abnormality of the choroidal circulation
characterized by an inner choroidal vascular network of
vessels ending in an aneurysmal bulge or outward projection,
visible clinically as a reddish-orange, spheroid, polyp-like
structure
• ICGA has been used to detect and characterize the PCV
abnormality with enhanced sensitivity and specificity.
• PCV is often misdiagnosed or confused with CSCR and with
exudative age-related maculopathy

20. Late-phase FA(A) shows a neurosensory retinal
detachment with multiple juxtapapillary “hot
spots.”
Early (B) and late (C) ICGA reveals the presence
of juxtapapillary polypoidal choroidal
vasculopathy

21. Late-phase FA image revealing type 1 occult choroidal neovascularization with a subfoveal pigment epithelium
detachment (PED) (A). Early (B) and late (C) ICGA demonstrate a distinct network of vessels within the macular choroid
ending with two hyperfluorescent “polyps.”

22. CENTRAL SEROUS CHORIORETINOPATHY
• It is characterized by multifocal areas of choroidal
hyperpermeability on ICGA, visible in the mid and late phases
of the angiogram.
• ICG assessment of the location of these areas of
hyperpermeability may be useful when considering treatment
with verteporfin PDT.

23. ICG (B) reveals a more extensive alteration of the choriocapillaries, with multiple
areas of hyper fluorescence

24. CHOROIDAL INFLAMMATORY DISEASE
It is a unilateral acute disease that affects young women,
presenting with a transient, self-limiting visual loss.
Multiple Evanescent white dot syndrome
Late phases FA -only mild alterations at the level of the outer retina and RPE(A).
Early phases ICGA (B) begin to reveal areas of hypofluorescence. size between 50 and 1000 µm, More
evident in the mid to late phases of the angiogram (C).

25. • ICG allows better staging and identification of active lesions.
• Active phase-Hypofluorescent areas with poorly defined
margins
• Aggressive phase-late hyperfluorescence
• Healed phase-Hypofluorescent areas with well defined
margins
Serpiginous Choroidopathy

26. CHOROIDAL TUMORS
• Circumscribed choroidal hemangioma are benign hamartomas
that are more difficult to diagnose.
• ICGA is the most useful study for demonstrating the intrinsic
vascular pattern of these tumors
Early-phase (ICGA) (49 seconds) - fine lacy vascular network of intrinsic vessels (C). Increasing hyperfluorescence(2min) is
detected after injection: (D) Increasing hyperfluorescence(5min) (E) Of note, the margins of the tumor appear scalloped. (F) Late-
phase ICGA study demonstrating hypofluorescence within the tumor (washout effect).

27. REFERENCES
• Ryan Retina
• Diseases of Retina and Vitreous: Spaide
• Yanoff
• Kanski

28. THANK YOU!!!