AF and ICG

Question 1

Excitation peak for fluorescein - nm and spectrum

Answer 1

490 nm (in the blue part of the spectrum)

Question 2

Emission - nm and color

Answer 2

530 nm - yellow-green light

Question 3

Excretion - where and how fast

Answer 3

in the urine over 24–36 hours

Question 4

Colors

Answer 4

White light from the camera is filtered so that blue light enters the eye (cobalt blue excitation filter). Yellow–green barrier filter blocks any blue light reflected from the eye, allowing only yellow–green emitted light to pass.

Question 5

Absolute contraindication

Answer 5

Fluorescein allergy

Question 6

Relative contraindications

Answer 6

severe reaction to any allergen, renal failure, pregnancy, moderate–severe asthma, significant cardiac disease.

Question 7

Adverse events in fluorescein angiography

Answer 7

Discoloration of skin and urine. Extravasation of injected dye, giving a painful local reaction. Nausea, vomiting. Itching, rash. Sneezing, wheezing. Vasovagal episode or syncope. Anaphylactic and anaphylactoid reactions. Myocardial infarction. Death

Question 8

choroidal (pre-arterial) phase - when

Answer 8

9–15 seconds after dye injection

Question 9

arterial phase - when

Answer 9

second after the onset of choroidal fluorescence

Question 10

Maximal perifoveal capillary filling is reached at

Answer 10

around 20–25 seconds

Question 11

Fluorescein is absent from the retinal vasculature after

Answer 11

about 10 minutes

Question 12

Autofluorescent

Answer 12

accumulated lipofuscin in the RPE, nerve head drusen, astrocytic hamartoma

Question 13

Window defect - when

Answer 13

atrophy or absence of the RPE, full-thickness macular hole, RPE tears and some drusen

Question 14

Window defect - characteristics

Answer 14

very early hyperfluorescence that increases in intensity and then fades without changing size or shape

Question 15

Pooling - pathophysiology

Answer 15

breakdown of the outer blood–retinal barrier (RPE tight junctions)

Question 16

Pooling - when

Answer 16

subretinal space, e.g. CSR - early hyperfluorescence, slowly increases in intensity and area, the maximum extent remaining relatively well defi. sub-RPE space, as in PED - early hyperfluorescence that increases in intensity but not in size

Question 17

Leakage

Answer 17

breakdown of the inner blood–retinal barrier due to:
○ Dysfunction or loss of existing vascular endothelial tight junctions as in background DR, RVO, CMO and papilloedema.
○ Primary absence of vascular endothelial tight junctions as in CNV, proliferative diabetic retinopathy, tumours and some vascular anomalies such as Coats disease.

Question 18

Staining

Answer 18

late phenomenon consisting of the prolonged retention of dye in entities such as drusen, fibrous tissue, exposed sclera and the normal optic disc

Question 19

ICGA - wavelength

Answer 19

near-infrared light

Question 20

ICGA - early

Answer 20

up to 60 seconds post-injection

Question 21

ICGA - early mid-phase

Answer 21

1–3 minutes

Question 22

ICGA - late mid-phase

Answer 22

3–15 minutes

Question 23

ICGA - late phase

Answer 23

15–45 minutes

Question 24

ICGA - contraindications

Answer 24

liver disease (excretion is hepatic), history of a severe reaction to any allergen, moderate or severe asthma and significant cardiac disease

Question 25

ICGA - Indications

Answer 25

PCV, Chronic central serous, Posterior uveitis, Choroidal tumours, Breaks in Bruch membrane such as lacquer cracks and angioid streaks, If FA is contraindicated

Question 26

Serous PED - AF

Answer 26

well demarcated oval area of hyperfluorescent pooling that increases in intensity but not in area. an indentation (notch) may signify CNV

Question 27

Serous PED - ICGA

Answer 27

oval hypofluorescent area with a surrounding hyperfluorescent ring. Occult CNV (focal hot spot or diffuse plaque) is detected in over 90%.

Question 28

Fibrovascular PED - FA

Answer 28

markedly irregular granular (stippled - punktowe) hyperfluorescence, with uneven (nierówny) filling of the PED, leakage and late staining

Question 29

Drusenoid PED - FA

Answer 29

Early diffuse hypofluorescence with patchy relatively faint early hyperfluorescence, progressing to moderate irregular late staining

Question 30

Haemorrhagic PED - FA

Answer 30

Dense masking of background fluorescence, but overlying vessels are visible

Question 31

Drusenoid PED - ICGA

Answer 31

Hypofluorescence predominates

Question 32

Retinal pigment epithelial tear - FA

Answer 32

Late phase shows hypofluorescence over the flap due to the thickened folded RPE, with adjacent hyperfluorescence, initially over the exposed choriocapillaris where the RPE is absent and later due to scleral staining

Question 33

Classic CNV - FA

Answer 33

well-defined ‘lacy’ pattern during early transit, subsequently leaking into the subretinal space over 1–2 minutes, with late staining of fibrous tissue

Question 34

Occult CNV - FA

Answer 34

its limits cannot be fully defined on FA

Question 35

RAP (retinal angiomatous proliferation) - ICGA

Answer 35

diagnostic. hot spot in mid and/or late frames and frequently a perfusing retinal arteriole and draining venule (hairpin loop)

Question 36

Ischaemic maculopathy

Answer 36

FA shows capillary non-perfusion at the fovea (an enlarged FAZ) and frequently other areas of capillary non-perfusion at the posterior pole and periphery

Question 37

Intraretinal microvascular abnormalities (IRMA) - FA

Answer 37

focal hyperfluorescence associated with adjacent areas of capillary closure (‘dropout’) but without leakage

Question 38

BRVO - FA

Answer 38

peripheral and macular ischaemia (capillary non-perfusion, staining of vessel walls, vessel ‘pruning’ – small branches failing to fill), haemorrhage and oedema with collateral vessels commonly forming in established cases. Venous filling is delayed

Question 39

Impending (partial) CRVO - FAF and FA

Answer 39

FAF may reveal a fern-like perivenular appearance, and FA generally demonstrates an impaired retinal circulation

Question 40

Non-ischaemic CRVO - FAF

Answer 40

characteristic fern-like perivenular hypoautofluorescence due to masking of background signal by oedema

Question 41

Non-ischaemic CRVO - FA

Answer 41

delayed arteriovenous transit time, masking by haemorrhage, usually good retinal capillary perfusion and some late leakage

Question 42

ischaemic CRVO - FA

Answer 42

marked delay in arteriovenous transit time, masking by retinal haemorrhages, extensive areas of capillary non-perfusion and vessel wall staining and leakage

Question 43

BRAO - FA

Answer 43

delay in arterial filling and hypofluorescence of the involved segment due to blockage of background fluorescence by retinal swelling

Question 44

Acute macular neuroretinopathy (AMN) - FA

Answer 44

normal or shows faint hypofluorescence

Question 45

Sympathetic ophthalmitis - FA

Answer 45

multiple foci of leakage at the level of the RPE, with subretinal pooling in the presence of exudative retinal detachment

Question 46

Sympathetic ophthalmitis - ICGA

Answer 46

hypofluorescent spots in active disease, which resolve with treatment