The purpose of this research study is to evaluate the effects of trehalose, an ingredient found in commercially available artificial tears, on the corneal barrier function. The investigators will assess corneal dryness and measure the relative corneal epithelial "barrier" function (the degree to which the cornea can prevent penetration of sodium fluorescein dye into the eye) after using eye drops that contain 3% trehalose for one month.
Adult subjects, > age 18 years, with moderate-to-severe dry eye, defined as fitting criteria for dry eye stages 3 or 4 of the MGD Workshop Management and Treatment subcommittee report.
Subjects must have normal eyelid position and closure.
For enrollment as aqueous tear deficiency, subjects must have a Schirmer I result of < 5.0 mm wetting in 5 minutes without anesthesia.
History or evidence of ocular or intraocular surgery in either eye within the past twelve months. LASIK and other kerato-refractive procedure patients can qualify if the most recent surgery or enhancement was 12 or more months prior.
History or evidence of serious ocular trauma in either eye within the past six months.
History of hypersensitivity to any component of the study medications.
History or evidence of epithelial herpes simplex keratitis (dendritic keratitis); vaccinia, active or recent varicella, viral disease of the cornea and/or conjunctiva; chronic bacterial disease of the cornea and/or conjunctiva; mycobacterial infection of the eye; and/or fungal disease of the eye.