ENLmedical.com: Conditions And Concerns: Medical Encyclopedia

Fluorescein eye stain

How the Test is Performed:
Dye is placed in the eye, using an "eye dropper" or blotting paper, and allowed to cover the surface of the cornea. The individual is asked to blink to move the dye. A cobalt blue light is then directed on the eye, causing the fluorescein to glow green. Abnormalities in the corneal epithelium will cause the dye to stain that region.

The ophthalmologist or optometrist (eye doctor) can determine the location and probable cause of the cornea problem depending on the size, location, and shape of the staining.

How to Prepare:
If contact lenses are worn, they will need to be removed before the test.

Infants and children:
The physical and psychological preparation you can provide for this or any test or procedure depends on your child's age, interests, previous experience, and level of trust. For specific information regarding how you can prepare your child, see the following topics as they correspond to your child's age:

infant test or procedure preparation (birth to 1 year)
toddler test or procedure preparation (1 to 3 years)
preschooler test or procedure preparation (3 to 6 years)
schoolage test or procedure preparation (6 to 12 years)
adolescent test or procedure preparation (12 to 18 years)

How it Feels:
If eyes are extremely dry, the blotting paper may be slightly scratchy. The dye feels like liquid in the eye and should not cause itching or other discomfort.

Risks:
If the fluorescein touches the skin surface, there may be a slight discoloration for a few days.

Why this Test is Performed:
This test is useful in determining if there is a scratch or other problem with the surface of the cornea. It can also be used to detect foreign bodies on the eye surface, and determine if there is an injury to the eye or eye infection. It can be used after contacts are prescribed to determine if there is adequate tear exchange between the cornea and the tear film.

Normal Values:
The cornea surface will appear uniformly colored with no foreign bodies.

Abnormal Results:

corneal abrasion (a scratch on the surface of the cornea)
infection
injury or trauma
foreign bodies (such as eyelashes or dust) (see eye - foreign object in )

Additional conditions under which the test may be performed:

blocked tear duct

Cost:
The estimated cost is $45 to $80 and is done as part of the routine eye examination .

Special Considerations:
This test is about 93 to 97% accurate for detecting injuries or abnormalities on the surface of the cornea.