2. `
Fluorescein is a synthetic organic
compound available as a dark
orange/red powder soluble in water
and alcohol.
3. Synthesis:
It can be prepared from phthalic
anhydride and resorcinol in the
presence of zinc chloride via
the Friedel-Crafts reaction.
Other name - Resorcinolphthalein
4. Medical applications :
In forensics and serology to detect latent blood stains
In Microbiology –To detect Leptospira strains under
microscopy
in Syphilis Serology (FTA-ABS Test)
In dentistry - a dye applied to teeth to reveal plaque
5. Fluorescein sodium is used extensively as a
diagnostic tool in the field of ophthalmology. It
is applied topically in the form of a drop or it
can be injected intravenously to produce a
fluorescein angiogram.
Topical fluorescein is useful in the diagnosis of
corneal abrasions, corneal ulcers, herpetic
corneal infections, and dry eye. Fluorescein
angiography is used to diagnose and
categorize macular degeneration, diabetic
retinopathy, inflammatory intraocular conditions,
and intraocular tumors
6. In ophthalmology
Ophthalmic research :
Intraocular dynamic studies [fluorometry]
Tear film drainage studies
Penetration to anterior segment structures
Fluorescein angiography [in acquired macular
& Retinal vascular patholgies]
Staining techniques
Test for dry eye
Evaluation of tear drainage
Applanation tonometry
7. Fluorescein angiography
Photographic surveillance of passage of fluorescein
through retinal and choroidal circulation
Principle: A molecule is excited
by light of certain wavelength
to a higher energy level ,release
photon then comes down to
original state
2 ml of 25 % [0r] 5 ml of 10 %
solution
8. 80 % protein bound and 20 % free into circulation
PROCEDURE:
White light from camera flash pass through
blue excitation filter [488 nm ] stimulates
Yellow – green barrier filter [533 nm] back into
camera film
A red free photograph is taken at 1 second interval 5-25 secs
after injection onset
12. Test for dry eye
Tear break up time
To test for tear film stability ,fluorescein dye is added to
the
eye and the tear film is observed under the slit lamp while
the
patient avoids blinking until tiny dry spots develop. The longer
it takes, the more stable the tear film. A short tear break-up
time is a sign of a poor tear film. Generally, >10 seconds is
thought to be normal, 5 to 10 seconds, marginal, and <5
seconds low
13. Tests for lacrimal drainage
Jones dye test :
To distinguish between Anatomical and functional
outflow problems
Instil one drop of fluorescein into the conjunctival
sac
Put a cotton bud soaked in anaesthetic in the
inferior meatus.
If fluorescein is detected after five minutes, the
system is patent (positive Primary Jones Test).
14. No fluorescein - Negative Primary Jones Test
and the functional obstruction could be anywhere
from the punctum to the Valve of Hasner.
Next, wash the excess fluorescein from the
conjunctival sac and syringe. Fluorescein detected,
entered the sac - positive Secondary Jones Test and
functional obstruction of the nasolacrimal duct.
If No dye after syringing, negative Secondary Jones
Test, because fluorescein not entered the sac and,
thus, there is stenosis of the puncta or canalicular
system - Anatomical obstruction.
15.
16. Applanation tonometry
The intraocular pressure is inferred from the
force required to flatten (applanate) a
constant area of the cornea, as per
the Imbert-Fick law.
1.Anaesthetic & fluorescein instilled in
conjuntival sac
2.With Cobalt blue filter,brightest illumination
and prism advanced until touches apex of
cornea
3.A pattern of 2 semicircles one above ,other
below the horizontal midline
17. 4. Dial is rotated to align inner margins of
semicircles to just touch each other
5.Reading on dial multiplied by 10 = Intraocular
pressure
