FUNDUS FLUORESCEIN ANGIOGRAPHY NISHITA AFRIN B.OPTOM 3rd batch ICO,CU

INTRODUCTION Fluorescein angiography refers to photographing fluorescein dye in the retinal vasculature following intravenous injection of fluorescein solution

FLUORESCENCE C20H12O5 Refers to fluorescein sodium (C20H10Na2O5) A brown or ornge red crystalline substance, alkaline in nature First synthesized in 1871 in Germany by Von Bayer

CONTINUE… Metabolized by liver and exerted by kidney Absorbs blue light (490nm ) and emits yellow-green light (530nm) Metabolized by liver and exerted by kidney

HAZARDS OF FLUORESCEIN DYE Reletively safe drug Temporary tan skin coloration Urine discoloration Transient nausea and vomiting More severe : hives ,asthmatic symptoms and laryngeal edema

CONTINUE… Myocardial infraction Respiratory and Cardiac arrest Syncope , anaphylactic reaction to fluorescein Myocardial infraction Respiratory and Cardiac arrest

INDOCYANINE GREEN Binds to plasma protein, confined to vascular system Cyanine dye Binds to plasma protein, confined to vascular system Molecular wt. 775 dalton Half life – 150- 180 dalton Remove from circulation by the liver to bile juice

Absorbs 600 nm -900 nm and emits 750 nm to 950 nm

General Principles of ICG Angiography 1. Binding 98% bound to proteins Less leakage from choriocapillaris 2. Fluorescence Much less than fluorescein Excitation peak 800 nm Emission at 835 nm 3. Filters Infrared barrier and excitation 4. Safer than fluorescein

Side effects of ICG… Sore throats and hot flashes Anaphylactic shock Risk in pregnancy Sore throats and hot flashes Anaphylactic shock Hypotension Trachycardia Dyspnea and Urticaria

CLINICAL USE OF FLUORESCENCE DYE Clinical use Research Care -treatment protocol for retinal diseases - to understand retinal and choroidal leisons . E.g. Age related macular degeneration, diabetic retinopathy ,retinal detachment…

Anatomic Considerations

FFA

General principles of FA Fluorescein 85% bound to serum proteins 15% unbound ‘free’ fluorescein Inner blood-retinal barrier (retinal capillaries) Impermeable to fluorescein Outer blood-retinal barrier (zonula occludens) Impermeable to fluorescein Choriocapillaris Permeable only to ‘free’ fluorescein

OPTICAL PRINCIPLE

Filters 1.Blue excitation filter 2.Yellow-green filter

PROCEDURE… Pupils should well dialed Patient seat infront of the camera Red free photographs taken Dye injected in the forearm or anticubital vein Photographs with fluorescein - 1 sec interval between 5 and 25 secs - late photographs after 10-15 mins

Syringe with NaF Insertion of needle containing Retractable needle with catheter system Mild hematoma

Angiographic phases: Five angiographic phases: Pre arterial (choroidal 9-15 seconds) Arterial Arteriovenous(capillary) Venous Recirculation

Circulation of NaF Dye injected from peripheral vein venous circulation heart arterial system INTERNAL CAROTID ARTERY Ophthalmic artery Short posterior ciliary artery) Central retinal artery (choroidal circulation.) ( retinal circulation) N.B. The choroidal filling is 1 second prior to the retinal filling.

1-Choroidal flush 2-Arterial phase

3-Arteriovenous phase

4-Venous phase Mid Phase Late Phase

Interpretation of FA

Red-free fundus photos Normal appearance Autofluorescence

Abnormal angiographic findings Hypofluorescence: Filling defect Blocking defect Hyperfluorescence : window defect Leakage Pooling Staining

Subretinal neovasculari- zation Choroid Tumor vessels Chorioretinal anastomosis Vascular tortuosities Dilation and shunts Anastomosis Neovascularization Hyperfluorescence Anomalous vessels Aneurysms Retina Teleangiectasia Tumor vessels Hamatoma Neovascularization Tortuosity Optic nerve head Dilation Hamatoma Tumor vessels

Retinal Cystoid edema In a preformed space (pooling) Subretinal Detachment of the pigment epithelium Hyper- fluorescence Leakage Detachment of the sensory retina Retina noncystoid edema Into tissue (staining) Subretinal e.g.dursen

Fibers, optic nerve drusen Drusen of the optic nerve head Autofluorescence Fluorescence without the administration of fluorescein Hamatoma Scleral exudate Scar tissue Pseudofluorescence Foreign body Myelinate nerve Fibers, optic nerve drusen

Causes of dark appearance of fovea Avascularity Blockage of background choroidal fluorescence by: Increased density of xanthophyll Large RPE cells with more melanin

Causes of hyperfluorescence RPE ‘ window’ defect Pooling of dye RPE atrophy (bull’s eye maculopathy Under RPE (pigment epithelial detachment) Under sensory retina (central serous retinopathy)

Causes of hyperfluorescence Leakage of dye Prolonged dye retention ( staining ) Into sensory retina (cystoid macular oedema) From new vessels (choroidal neovascularization Associated with drusen

Capillary non-perfusion Causes of hypofluorescence Vascular occlusion Loss of vascular tissue Capillary non-perfusion (venous occlusion) Choroideremia or high myopia

Red-free fundus photos Normal appearance Autofluorescence

Autofluorescence

Macular hole

CHOROIDAL NAEVUS

DIABETIC MACULOPATHY TREATED WITH LASER

BACKGROUND DIABETIC RETINOPATHY

CENTRAL SEROUS RETINOPATHY

PROLIFERATIVE DIABETIC RETINOPATHY (early venous phase)

Stargardt's Disease

DIABETIC AND HYPERTENSIVE RETINOPATHY

Limitations of FFA 1) Does not permit study of choroidal circulation details due to a) melanin in RPE b) low mol wt of fluorescein 2) More adverse reaction 3) Inability to obtain angiogram in patient with excess hemoglobin or serum protein.e.g. polycythemia weldenstrom macroglobulenaemia binding of fluorescein with excess Hb or protein Lack of freely circulating molecule

THANKS TO ALL