Digital Image Based Determination of Ocular Surface Vital Dye Staining

To compare digital image analysis of ocular surface vital dye staining with standard slit lamp clinical assessment and therefore explore its suitability as an outcome measure for clinical trials.

Ocular surface staining with vital dyes is an integral component of ophthalmic examination of the cornea and conjunctiva. Various dyes such as sodium fluorescein are used to delineate or highlight areas of ocular surface abnormality ranging from devitalized mucin-deficient conjunctival epithelium to frank corneal epithelial abrasion or erosion. Since the cornea is a transparent structure, visualization of subtle abnormalities of the surface epithelium can be enhanced with special viewing techniques such as specular microscopy, sclerotic scatter, retro-illumination or with staining of the surface. The magnitude or the degree of staining of the ocular surface is a manifestation of damage to the corneal and conjunctival epithelium and is often used as an outcome measure for the study of treatment of corneal and external diseases. The amount of the staining is not the only important characteristic evaluated by the physician. The pattern of the staining may be splotchy, diffuse or punctate, or may be located on different parts of the cornea or conjunctiva. The clinician documents the pattern, nature and amount of staining and taken together with the other aspects of the examination provide vital information to the clinician for determining the patient’s diagnosis. Vital dyes are colored solutions that are applied as eye drops in the evaluation of the health of the ocular surface. Both the conjunctiva and cornea are transparent structures; while, blood vessels course through the conjunctiva, the cornea is avascular. The use of topically applied dyes such as sodium fluorescein and lissamine green which stain diseased or damaged tissue enhances the clinician’s visualization of ocular surface abnormalities. Patients with varying degrees of ocular surface disease undergo vital dye staining as a routine part of their ophthalmic evaluation. The nature, degree and pattern of staining assist in the determination of diagnoses, assessment of disease severity and documentation of treatment effects. The magnitude of staining is an indicator of overall ocular surface damage and as such is commonly used as an outcome measure in clinical trials of treatments for dry eye.

Patients being evaluated for ocular surface disease will undergo digital photography of ocular surface staining using a standardized operating procedure. The vital dye stains to be employed are 2% sodium fluorescein and 0.5 % lissamine green which are readily available and routinely used in the ophthalmology clinic for the evaluation of these patients. Sodium fluorescein stains areas of corneal epithelial cell loss; whereas, lissamine green stains epithelium that is mucin-deficient or degenerating. Five microliters of sodium fluorescein and 10 microliters of lissamine green will be delivered to the ocular surface with a capillary tube. Fluorescein staining is visualized with the Cobalt blue filter and highest intensity illumination of a standard slit lamp biomicroscope using 16 X magnification. Lissamine green staining is best visualized with low intensity white light at 16X magnification. Clinical grading of fluorescein staining is evaluated between 30 seconds and 2 minutes of dye instillation; whereas, lissamine green dye starts to diffuse out of the tissues after about 90 seconds after instillation. Corneal fluorescein photographs will also be obtained 2 minutes after dye instillation and conjunctival lissamine green photographs will be taken starting 1 minute after dye instillation. In this study, both eyes of 30 patients will have digital slit lamp photographs of ocular surface staining performed by the NEI photography staff using standard operating procedures (SOP) and simultaneous clinical grading of dye staining.

Individuals with ocular surface dysfunction and/or disease are eligible for inclusion in this study. Patients who cannot hold their eyes open long enough for the photographs to be taken or who has a known allergy to sodium fluorescein or lissamine green will be excluded. Children 2 years of age or younger will be excluded since they will not be able to cooperate for slit lamp photography

Recruiting. Comments: For consideration for inclusion in this study, you may contact Ms. Linda Goodman, COT at 301-435-1833.

Ongoing. Comments: Study is ongoing and open for recruitment.

Results are not yet available.