Assessment of Cornea and Tear Smoothness in an Autoimmune Dry Eye Rat Model

The tear film covering the cornea consists of lipid, water, and mucin produced by various secretory glands. Dysfunctioning of lacrimal and meibomian glands affects tear film stability and cornea smoothness, resulting in dry eye disease.

To measure cornea and tear smoothness, position an anesthetized autoimmune rat model under a stereomicroscope equipped with a ring illuminator featuring evenly spaced LED  lights encircling the objective lens.

Moisten the ocular surface with saline and spread it evenly for accurate smoothness assessment.

Focus the ring illuminator on the cornea's center, generating an illuminator ring image with two circular rows of dots.

In the unaffected control rat, the illuminator ring image on the ocular surface is round with evenly spaced dots, indicating a smooth cornea with a stable tear film.

Conversely, the distorted image of an autoimmune rat model indicates reduced corneal smoothness and unstable tear film, confirming dry eye disease.