Efficacy and Safety of PRO-148 Ophthalmic Solution Versus SYSTANE® in the Treatment of Patients With Dry Eye Syndrome

Inclusion Criteria: * Patients with diagnosis of mild-to-moderate drye eye syndrome. * Male or female patients. * Patients 18 years of age Exclusion Criteria: * Patients with one blind eye. * Visual acuity of 20/40 in any eye * Patients with history of active stage of any other concomitant ocular disease. * Patients taking any medication, topically or by any other route, which could interfere with the study's results, in the 3 days prior to trial or until a time period in which residual effects could be present. * Contraindications or sensitivity to any component of the study treatments. * Ocular surgery within the past 3 months. * Contact lens users. * Females of childbearing potential )may not participate in the study if any of the following conditions exist: * They are pregnant, * They are breastfeeding, * They have a positive urine pregnancy test at screening, * They intend to become pregnant during the study, or * They do not agree to use adequate birth control methods for the duration of the study. * Participation in any studies of investigational drugs within 90 days previous to the inclusion. Discontinuation criteria: * Patients could be discontinued before the completion of the study because of adverse events, pregnancy, protocol violations, lack of efficacy, or administrative reasons.