Dry eye syndrome, also known as keratoconjunctivitis sicca or KCS, is a disorder of the tear film leading to damage to the ocular surface and ocular discomfort. In aqueous tear deficient dry eye, there is inadequate tear production. Patients with dry eye include those who have KCS and those with a more severe form of KCS associated with Sjogren's Syndrome (SS). In SS, lymphocytic infiltration of the lacrimal gland leads to destruction of acinar structures and impaired glandular function. Although most cases of KCS are not due to Sjogren's Syndrome, lymphocytic infiltration of the lacrimal glands of non-Sjogren's KCS patients has been demonstrated and some authors suggest that age-related atrophic changes of the lacrimal gland may be secondary to a chronic progressive inflammatory process. Several clinical studies have indicated that systemic or topical CsA improves some objective or subjective signs of KCS in patients with or without SS. In this protocol, patients with aqueous tear deficient KCS will be randomized to treatment with topical CsA 0.1% or the emulsion vehicle. To determine the safety and efficacy of CsA 0.1% treatment in patients with KCS, comprehensive ophthalmologic examinations and standardized symptom assessments will be performed. In addition, to determine the ability of topical CSA to alter ocular surface inflammation, pre- and post-treatment conjunctival biopsy specimens will be analyzed for infiltrating lymphocytes.