Among them the investigators can mention recurrent and chronic conjunctivitis, keratoconjunctivitis sicca and dry eye, affecting 23% of patients undergoing radioactive iodine therapy. Dysfunction of the lacrimal gland is described in recent studies, especially after high cumulative dose of the drug. Likewise, epiphora and nasolacrimal duct obstruction have been reported as complications associated with the use of radioiodine, although studies are not available to assess its true incidence through the systematic evaluation of patients.