FLASHLIGHT FOR FLUORESCEIN TEST-
ULTRAVIOLET LIGHT (NUV) - INFORMATION
FLASHLIGHT FOR FLUORESCEIN TEST- ULTRAVIOLET LIGHT (NUV) - INFORMATION
THE ESSENCE OF THE METHOD
Flashlight for fluorescein test (ULTRAVIOLET LIGHT (NUV) - emits ultraviolet light at the border of the visible part of the purple spectrum (near or far-wave ultraviolet radiation).
Unlike medium-wave and short-wave (hard) ultraviolet radiation, near-ultraviolet radiation is relatively safe for the eyes and does not cause damage to the retina. Part of the ultraviolet rays of the near spectrum are invisible to the eye, and a person perceives only the purple part of the spectrum at the 400 nm border.
However, UV rays invisible to the eye can cause intense fluorescence of the illuminated object (if it is capable of fluorescence) (Fig.1, 2).
Figure 1. Visible part of the purple spectrum. Figure 2. Intense fluorescence of
the fluorescein paint applied to the line.
When conducting a fluorescein test, an aqueous solution of sodium fluorescein after applying to the surface of the eyeball and washing off excess dye, stains the de-epithelized areas of the cornea and conjunctiva. When UV light interacts with particles of attached paint, bright fluorescence occurs, which is clearly visible to the naked eye, even if the amount of dye on the tissue is minimal (Fig. 3, 4).
Figure 3. Fluorescence of corneal erosions Figure 4. Fluorescence of corneal erosion
in Mini Bull-Terriers. in a French bulldog.
ADVANTAGES
In many cases, weak fluorescein staining of corneal or conjunctival defects may be invisible to the ophthalmologist. This is especially true in the case of old ulcers and corneal erosions, when the fluorescein dye is poorly sorbed on a partially necrotic surface, giving a weak yellow, poorly visible color. The ULTRAVIOLET LIGHT (NUV) illuminator produces intense, highly visible fluorescence even with a minimal amount of dye. The use of a flashlight for the ULTRAVIOLET LIGHT (NUV) fluorescein test significantly increases the diagnostic sensitivity and informative value of this method.
