Corneal Fluorescein Staining
Corneal fluorescein staining highlights areas where the corneal epithelial barrier is disrupted. It is useful in dry eye disease, exposure, contact-lens related epithelial injury, toxic or medicamentosa keratopathy, recurrent erosion and many other ocular-surface disorders.
How to do the test
- Instil fluorescein into the lower conjunctival sac and allow the patient to blink several times.
- Select the Fluorescein imaging mode in OSDx.
- Focus the entire cornea with the eye looking straight ahead.
- Acquire the image when the cornea is sharply focused and the staining pattern is clearly visible.
- If required, repeat the image after repositioning so that the full corneal surface is documented.
What to look for
- Punctate epithelial staining — commonly seen in dry eye and exposure-related disease.
- Inferior staining — may be associated with exposure, lid disease or tear-film instability.
- Interpalpebral staining — often accompanies evaporative ocular-surface disease.
- Focal or geographic staining — may indicate local epithelial trauma or more significant epithelial disease.
OSDx can assist in documenting the extent of corneal fluorescein staining and, where the analysis
feature is available, quantify the stained area as a percentage of the analysed corneal surface.
This can be useful for objective comparison during follow-up.
Interpretation
The distribution and pattern of staining are often as important as the total amount of staining. Always interpret the image in the context of symptoms, tear-film stability, lid findings and the rest of the ocular-surface examination.
Avoid interpreting a heavily flooded fluorescein image immediately after instillation. Allow the
dye to distribute evenly before documenting the corneal staining pattern.