Unit 3 - FFA/ICG/FAF

Question 1

What do FFA’s look at?

Answer 1

Retinal vasculature

Question 2

What do ICG images look at?

Answer 2

Choroidal blood flow

Question 3

What wavelength excites NaF and what wavelength does it emit at?

Answer 3

Blue light (465-490)

Emits yellow-green (520-530)

Question 4

What wavelength does ICG absorb and then emit?

Answer 4

Near IR range (790-805)

Fluoresces at (830nm)

Question 5

What does NaF bind to?

Answer 5

Serum albumin with remaining free fluorescein being blocked by blood-ocular barrier. (choriocapillaris has fenestrations so will leak it)

Question 6

What does ICG bind to?

Answer 6

98 % protein bound, mainly to large sized proteins. e.g. globulins, albumin and lipoproteins

Question 7

What 6 risks are associated with FFA?

Answer 7

Hot flushes

Local erythema (sunburn)

Anaphylactic shock

Shortness of breath

Nausea

Vomiting

Question 8

What 6 risks are associated with ICG?

Answer 8

1. Hot flushes
2. Local erythema (sunburn)
3. Anaphylactic shock
4. Shortness of breath
5. Sore throat
6. Urticaria

Question 9

What contraindications are there to ICG and FFA?

Answer 9

Shellfish or iodine allergy

Question 10

What % of NaF is used

Answer 10

20% intravenously

Question 11

What dosage of ICG is used?
What is the maximum safe dose?

Answer 11

40mg in 2mL
5mg/Kg

Question 12

What is the appearance of the disc in ICG, FFA, FAF and red free?

Answer 12

FFA - light
Red free - light
FAF - dark
ICG - dark

Question 13

What type of pattern would you see in FFA with a scar?

Answer 13

Staining

Question 14

What is the definition of FFA leakage?

Answer 14

Pattern that increases in size and intensity as the study continues.

Question 15

What is the definition of FFA pooling?

Answer 15

Pattern that increases in intensity but not size e.g. PED

Question 16

What causes are there of blocked FFA images?

Answer 16

1. Cataract
2. VH
3. Retinal Haems

Question 17

What are the four phases of FFA and their times?

Answer 17

1. Choroidal flush (8-12secs)
2. Arteriovenous phase (11-18secs) Retinal arteries
3. Lamellar venous phase ( 15-22secs) Retinal veins in lamellar patter
4. Maximal flourescence (22-30 secs)

Question 18

What are the three phases of ICG and their times?

Answer 18

1.Early phase (0-3mins), choroid hyperflouresces
2. Intermediate phase (3-10mins), maximal fluroscence
3. Late phase (28-30 mins), large choroidal vessels appear dark against the bright stromal flourescence

Question 19

What does FAF look at?

Answer 19

Evaluation of RPE

Question 20

Which pigment causes autoflourscence?

Answer 20

lipofuscin

Question 21

What light is used to look at FAF?

Answer 21

Blue laser (488nm) observed using a 500nm filter.

Question 22

What do the optic disc and blood vessels look like in FAF?

Answer 22

Dark

Question 23

What does hypofluorescence in FAF indicate?

Answer 23

Reduced metabolic demand in RPE

Question 24

What does hyperfluorescence in FAF indicate?

Answer 24

Increased metabolic demand e.g.e inflammation

Question 25

What does increase flourescence at the edge of a dark area in FAF indicate?

Answer 25

Increasing GA

Question 26

What machine produced blue light FAF and which green?

Answer 26

Spectralis = blue Optos - green

Question 27

Which vein is fluorescein injected into?

Answer 27

Antecubital vein

Question 28

How is ICG excreted and what patients does this stop from having it?

Answer 28

Liver, not suitable for patients in liver failure