Use of topical ocular medications during the study period. Subjects using systemic steroids, immunosuppressive agents and/or anti-cholinergics (e.g. cold and allergy medications, tricyclic antidepressants) for treatment of autoimmune connective tissue disease may not be enrolled in the study if they have not been on a stable dosing regimen for a minimum of 30 days prior to the Eligibility Visit. In addition, the dosing regimen must remain stable throughout the 4-week treatment period.