3. FFA ■ Fluorescence: is luminance that
is maintained when tissue
excited at one wavelength
(blue) and is emitted
immediately through a longer
wavelength (green-yellow).
5. Equipment for
fluorescein
angiography
• Fundus camera with
digital imaging system.
• Matched fluorescein
barrier & exciter
filters.
• Canula , 5 ml syringe,
tourniquet, alcohol
swab, bandage.
• Fluorescein solution.
• Standard emergency
equipment.
6. Sodium fluorescein
An organic
water soluble
vegetable dye
(orange-red)
Dose not diffuse
out through
blood retinal
barrier,
Not suitable to
study choroidal
circulation.
Eliminated by
liver & kidneys
with in 24 hours
Fluorescein
solutions:
10 ml of 5% 5 ml of 10% 3 ml of 25%
7. Contraindications of FFA:
■ Fluorescein allergy (absolute )
■ Relative contraindications:
■ Renal or hepatic failure, asthma, cardiac
disease , pregnancy
NOTE : sea food & iodine allergy
contraindicated for indocyanine green = ICG
is used mainly for choroidal vasculature
angiography.
8. Adverse reaction of
FA
■ Discolouration of skin & urine
■ Nausea (very common ) +/- vomiting
■ Pain full local reaction due to
extravasation of the dye
■ Itching, rash
■ Sneezing, wheezing
■ Vasovagal episode or syncope
■ Anaphylactic reaction (hypotensive,
narrow air ways ,bronchoconstriction,
erythema, tachycardia, angioedema,
rapid irregular pulse, =anaphylactic
shock=death
■ Cardiac arrest or myocardial infarction)
■ Death (1:200 000)
10. steps
of
FFA
Take
Take red-free photo (with yellow -green filter on )
,controle autofluorecint photo with bothe blue & green-
yellow filters on
Position
Position patient for comfort, aligment for good camera
picture focus
Prepare Prepare machine & lenses
Prepare prepare emergency drugs, vomiting bag)
Prepare Prepare equipment (e.g dye, insert venous cannula)
Dilate Dilate pupils
Take Take informed consent
11. Steps of FFA
Shoot exactly at start & finish of fluoresine injection
Then again start shooting 5-10 seconds after inj.
-take images every 1-2 seconds till complet phase desired
Take late images at 10 -20 minutes
Can add stereo images
17. Optical coherence tomography
&angiography (OCT & OCT-A )
■ Definition : OCT, is a noncontact,
non-invasive imaging technique used to
obtain high resolution cross-sectional
images of tissues.
■ most important diagnostic tool for
retinal pathology
■ Measures reflected infrared light from
tissue discontinuities to give 2 D or 3 D
images
■ It gives quantitative (measure thickness ),
qualitative (describe structure ) value
18.
19. Ocular coherence tomography aniogram
OCT-A
■ OCT-A : It is a fast imaging tool, detecting streaming blood,
thereby allowing to construct an image of the retinal
vasculature.
■ in contrast to “classical” FA it is dye-free, and therefore lacks
significant side effects
■ OCT-A visualizes the superficial, the deep and the choroidal
vascular network; the middle capillary plexus and optic disc
vasculature, foveal avascular zone (FAZ)
20.
21. Indications of OCT/ OCT-A
■ Macula :Diagnosis of diseases,
monitoring of its progression or
respons to treatment: e.g CME,
CNV, VMT, macular hole, CSR
■ Optic nerve head & retinal nerve
fiber : analysis e.g: glaucoma
neuropathy
■ Anterior segment: corneal
pathology, pre & post surgery,
pachymetry , anterior chamber
angle in glaucoma
23. OCT/OCT-A
■ Limited : by media opacities , blind or poor fixating eye, undilated pupils,
■ Artefacts in the OCT scan are anomalies in the scan that are not accurate
images of actual physical structure , but are rather the result of an external
agent or action (e.g blink or eye movement) or in pathological myopic
fundus & tilted disc.
■ Poor OCT signal can give inaccurate results.
24. Scaning OCT/OCT-A tips
1. Communicate with the doctor regarding the pathology of
interest. Specify OCT option.
2. Check patient vision reliability
3. Review past OCT exams
4. Dilate the eyes well.
5. The patient must keep the forehead against the bar and
the chin in the chinrest, with teeth together.
