MUC5AC and dry eye syndrome: For the first time, we demonstrated the evaporative component disturbance in rheumatoid arthritis patients, with the presence of meibomian gland dysfunction (associated with alterations in the lipid layer of tear film) as well as decreased goblet cells count (associated with the mucin layer of the tear film), in addition to the traditional aqueous tear deficiency related to keratoconjunctivitis sicca.