Tear Film Breakup Time

Описание: Learn more... Read the TFOS Dry Eye Workshop Report: http://www.tearfilm.org/tearfilm-repo...
Surface damage to the eye can be demonstrated using dyes such as fluorescein and lissamine green.
The amount of damage can be graded by reference to standardized grading charts.
For reasons of contrast and visibility of the staining patterns it is common practice to use fluorescein when estimating surface damage to the cornea and lissamine green when assessing damage to the bulbar conjunctiva
However, when the fluorescence of fluorescein is viewed through a yellow barrier filter such as a Kodak 12 or 15, staining can be readily graded on the bulbar conjunctiva.
All slit-lamps are equipped with a blue light source, though absorption characteristics will vary. This could modify the fluorescence.
Background notes
Viewing fluorescence on the cornea is greatly enhanced by placing a yellow barrier filter over the oculars of the slit lamp.
It also allows fluorescein staining to be observed over the conjunctiva
Fluorescein staining spreads rapidly into the tissues and so assessment is best made immediately after instillation.
If photography is intended then the dye should be instilled with the patient already seated in front of the slit lamp camera.
For general clinical use, an impregnated fluorescein strip is used in a standardized manner.
A single drop of unit-dose saline is placed on the impregnated tip of the fluorescein strip. As soon as the tip is fully wetted, the excess is shaken off briskly and the drop is delivered quickly and lightly to the back of, first the right and then the left tarsal plate.