OPT 223 Intravenous Fluorescein Angiography (IVFA)

What is IVFA used for?

diagnostic procedure using intravenous dye to visualize and evaluate the integrity of retinal and choroidal circulation

What are potential indications for IVFA?

-Proliferative diabetic retinopathy

-Exudative macular degeneration

-Ocular ischemic syndrome

-Vessel occlusions

-White dot syndromes

-Choroidal melanoma

When is IVFA contraindicated?

-allergy to fluorescein dye

-pregnancy (category C)

-poor GFR (<90)

What are common adverse effects of IVFA?

-Yellowing of skin and urine

-Transient nausea (3-15% of cases)

-Vomiting (7% of cases)

-Pruritis (itching)

-Extravasation of dye (leakage of dye into extracellular tissue, outside blood vessel)

-Mild pain and redness or bruising

What are rare adverse effects of IVFA?

-Urticaria (hives)

-Pyrexia (fever)

-Thrombophlebitis

-Syncope (fainting)

-Bronchospasm

-Anaphylaxis

-Cardiac arrest

What patient history must be taken into account for IVFA preparation?

-Review diagnoses and safety for procedure

-Demographic (visibility of veins)

-Medical history (contraindications or considerations)

-Age/weight (access to veins)

-Allergies (contraindications)

What exam findings must be taken into account for IVFA preparation?

-Abnormalities (which eye, location desired)

-Ability to visualize retina

-Fixation and cooperation ability

-Non invasive testing

What needs to be done in terms of consent for IVFA?

-Description of procedure

-Preparation before appt (see form)

-Indication, risks and benefits, alternatives

-Consider history update, checking BCVA and vitals (BP/pulse)

-Dilate

What is done for post procedure documentation?

-Drug, dose, delivery method, location (i.e. 25% NaFl intravenous right arm medial cubital vein")

-Interpretation of results

-Any complications

What equipment is needed for IVFA?

-Anti-septic environment (sanitize, drape)

-Prepared fluorescein (intravenous)

-Prepared epinephrine (intramuscular) or epipen (for allergic reaction or anaphylaxis)

-+/- prepared diphenhydramine (for itching)

-Needles, syringes, gloves, alcohol wipes, cotton balls, band-aids, etc.

What should be used for an allergic reaction during IVFA?

epinephrine (and then seek medical attention)

What percent of NaFl binds to serum proteins?

60-80% (NaFl flows from arm to eye)

Flow:

median cubital to heart and then leaves heart as oxygenated blood to internal carotid artery to ophthalmic artery to central retinal artery and short posterior ciliary arteries

What powers are available for IVFA?

-30D

-50D

depending on the lens, can focus on the macula, posterior pole

What are the expectations for a normal IVFA?

-Prior to sodium fluorescein reaching eye, the entire posterior segment is fairly dark or hypofluorescent

-As angiogram phases continue, macula continues to appear dark (hypofluorescent) due to heavy pigment carotenoids and foveal avascular zone, while optic disc stains with mild hyperfluorescence over time due to capillary perfusion

What are the phases of IVFA?

-pre arterial or choroidal flush

-arterial

-arteriovenous

-peak

-venous (laminar)

-venous (complete)

-late/recirculation

Describe the pre arterial or choroidal flush phase.

time: 8-12 seconds (but up to 20)

-patchy hyper fluorescence, followed by overall hyper fluorescent glow of retina (fenestrated choroidal arteries)

Describe the arterial phase (IVFA).

time: 12-15 seconds (1-3 seconds after choroidal flush)

-all four artery branches fill simultaneously

Describe the arteriovenous phase.

transitions from artery to vein via capillaries

Describe the peak phase.

time: 20-30 seconds

-optimal time to see FAZ

Describe the venous (laminar) phase.

time:15-20 seconds (by 30)

-vein walls appear hyper fluorescent but center lumen appears hypo fluorescent

Describe the venous (complete) phase.

time: 45-60 seconds

-all vessels hyper fluorescent, including vein lumen

Describe the late/recirculation phase.

time:2-5 minutes (up to 20 min)

-gradual reduction of fluorescein after 10 min, retinal vessels are devoid of fluorescein and choroidal flush is barely visible (optimal time to identify late leakage)

What abnormalities in timing are present for IVFA?

-delayed arm to eye time

-patchy choroidal filling/flush

-delayed filling of a retinal vascular branch (branch retinal artery occlusion)

What are things that result in hypo fluorescence on IVFA?

-blockage

-impaired vascular filling

-atrophy

What are things that result in hyper fluorescence on IVFA?

-leakage

-pooling

-staining

-RPE atrophy

Why does leakage appear hyper fluorescent?

Hyperfluorescence progressively enlarges throughout the angiogram with fuzzy borders because the dye permeates out of leaky, incompetent blood vessels

occurs in neovascularization, disc edema

Why does pooling appear hyper fluorescent (IVFA) ?

Hyperfluorescence progressively enlarges to fill the fluid cavity and then becomes fixed in size

occurs in retinal edema, sensory retinal detachment, RPE detachment

Why does staining appear hyper fluorescent (IVFA)?

Late hyperfluorescence due to accumulation of fluorescein dye; the hyperfluorescence gradually gets brighter (but not as bright as pooling/leaking), but the size stays the same

occurs in sclera, ONH, drusen, glial tissue, fibrotic scarring

Why does RPE atrophy appear hyper fluorescent (IVFA)?

Defect in the RPE allows transillumination of the choroidal hyperfluorescence; remains static in size and brightness and becomes fluorescent with the choroidal phase before the arteries even fill in the early frames.

occurs with RPE loss or retinal hole