Rose Bengal Staining
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Rose Bengal Staining:
Rose Bengal stains devitalized epithelial cells that lack a healthy mucin coating. It is applied using a dye-impregnated paper strip.
The rose bengal staining indirectly ascertains the reduced tear secretion by detection of damaged epithelial cells.
Rose bengal, a vital dye, stains the dead and dying epithelial cells.
A positive test reveals a triangular staining of the nasal and the temporal bulbar conjunctiva in the exposed interpalpebral area.
A punctate staining in the lower two-thirds of the cornea may occasionally be seen.
The test is useful in the diagnosis of keratoconjunctivitis sicca.
Ocular surface is divided into three zones:
2. Nasal bulbar conjunctiva.
3. Temporal bulbar conjunctiva.
Each zone is evaluated for the density of stain and given score of:
1: Mild staining
2: Moderate staining
3: Severe staining.
Rose Bengal Staining density of stain
A total score of more than 3.5 is taken as positive for dry eye.
Interpretation of staining is based on intensity and location using a grading scale described by van Bijsterveld . The nasal and temporal conjunctiva and the cornea are graded on a scale of 0-3 with a maximum possible score of 9.
In aqueous tear deficiency, the interpalpebral conjunctiva is the most common location for Rose Bengal staining. The severity of staining has been shown to correlate with the degree of aqueous deficiency, tear film instability, and reduced mucin production by conjunctival goblet and epithelial cells(2)
Reference: (1) Van Bijsterveld OP. Diagnostic tests in the Sicca syndrome. Arch Ophthalmol. 1969;82:10-14
(2)Methodologies to diagnose and monitor dry eye disease: report of the Diagnostic Methodology Subcommitte of the International Dry Eye WorkShop (2007). Ocul Surf. 2007;5:108-152.
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