This is a prospective, comparative, contralateral eye study. Patients older than 18 years who have had treatment with topical lubricants for at least 1 month and persist with symptoms of dry eye and corneal staining with fluorescein were included. Patients with dry eye attributable to abnormalities of the eyelids, nasolacrimal obstruction and active corneal infection, as well as patients with severe dry eye were excluded from the study. One eye randomly received a subcutaneous injection of botulinum toxin in the medial part of the lower eyelid, and the other eye received a similar procedure with placebo. The subjective evaluation was achieved with a questionnaire assessing symptoms of dry eye and conjunctivitis, quality of vision and ocular comfort level each eye separately. The objective evaluation included the measurement of the tear film break up time, Schirmer's test and with a modification of the Oxford grading scheme for corneal and conjunctival staining.