Fluorescence is a form of luminescence where a material absorbs high-energy photons and emits lower-energy photons. Sodium fluorescein, the dye used in fluorescein angiography, is excited by blue light and emits green-yellow light. It readily diffuses through fenestrated vessels but not healthy retinal vessels or the retinal pigment epithelium, making it useful for diagnosis. Successful fluorescein angiography requires an excitation filter to allow specific wavelengths of light to pass and a barrier filter to select the emission wavelengths.

1. PRINCIPIOS DE LA
ANGIOGRAFÍA CON
FLUORESCEÍNA
(Parte I)
Carlos Azañero Inope
Residente - Oftalmología

2. PRINCIPIOS DE LA ANGIOGRAFÍA CON FLUORESCEÍNA
Fluorescence is a form of
luminescence, or cold-body
radiation, characterized by the excitation
of a material with a high energy (short
wavelength) photon with subsequent
release of a lower energy (longer
wavelength) photon.
Dr.Carlos Augusto Azañero Inope
www.carlosvirtual.com

3. PRINCIPIOS DE LA ANGIOGRAFÍA CON FLUORESCEÍNA
Sodium fluorescein, NaC20H12O5, is a
hydrocarbon that is excited by
wavelengths from 465 to 490 nm (blue)
and emits light at a wavelength of 520
530 nm (green–yellow)
Dr.Carlos Augusto Azañero Inope
www.carlosvirtual.com

4. PRINCIPIOS DE LA ANGIOGRAFÍA CON FLUORESCEÍNA
Dr.Carlos Augusto Azañero Inope
www.carlosvirtual.com

5. PRINCIPIOS DE LA ANGIOGRAFÍA CON FLUORESCEÍNA
Successful fluorescein angiography relies upon two interference
filters, which allow only a narrow bandwidth of light to pass, an
excitation and a barrier filter.
Dr.Carlos Augusto Azañero Inope
www.carlosvirtual.com

6. PRINCIPIOS DE LA ANGIOGRAFÍA CON FLUORESCEÍNA
Sodium fluorescein is a low molecular
weight molecule (367 Da) and readily
diffuses through the fenestrated vessels
of the choriocapillaris, but does not
pass through healthy endothelial cells
of nonfenestrated retinal vessels or
through the retinal pigment epithelium
(RPE); this property is useful
diagnostically.
Dr.Carlos Augusto Azañero Inope
www.carlosvirtual.com

7. PRINCIPIOS DE LA ANGIOGRAFÍA CON FLUORESCEÍNA
In humans, only one- fifth of sodium
fluorescein remains unbound in the
bloodstream and is available for
imaging; the rest remains protein-
bound, primarily to albumin.
Dr.Carlos Augusto Azañero Inope
www.carlosvirtual.com