Ocular Surface Immune Response in Dry Eye Disease

For Dry Eye Disease Participants Inclusion Criteria: * Age \>18 * Ability to consent to study * Symptoms of dry eye disease for at least 6 months, such foreign body sensation, burning, stinging, light sensitivity * Positive vital dye staining of the cornea * At least one of the following objective signs: (Schirmer I \<10 mm at 5 minutes), decreased (\<0.2 mm) tear meniscus, decreased tear breakup time (TBUT) of \<10 seconds, positive vital dye staining of the conjunctiva For Age-Match Controls Inclusion Criteria: * Between the ages of 18-89 * The ability to provide informed consent for study inclusion * Clear, healthy cornea * Normal tear meniscus (\> 0.3 mm) For Dry Eye Disease Participants Exclusion Criteria: * History of contact lens wear in the past 3 months * History of ocular surgery in the past 6 months * Active ocular allergies * History of ocular infection in the past 3 months * History of diabetes * History of topical or systemic anti-inflammatory therapy in the past 1 month For Age-Match Controls Exclusion Criteria: * History of ocular or eyelid surgery within the past 12 months * History of herpetic or other infectious keratitis or other inflammatory eye disease * History of any other acute ocular disease * Current use of topical medications (not including artificial tears) * Current use of contact lenses * History of ocular carcinoma or any recent ocular topical chemotherapy or radiotherapy * History of cancer elsewhere in the body which is currently under systemic chemotherapy * Current glaucoma disease requiring use of glaucoma drops * History of Diabetes mellitus * Current diagnosis of dry eye disease