Investigators anticipate that alterations in corneal nerve and dendritic cell parameters will correlate with immune activation/inflammation, deterioration of tear function and increased systemic severity of the rheumatological disease. In addition, the investigator hypothesize that the lower the corneal nerve density, the higher the number of corneal dendritic cells and conjunctival inflammatory cells. Studying these relationships may allow a better mechanistic understanding of local corneal and systemic immune activation and the development of a non-invasive ophthalmic surrogate marker of dendritic cell activation and nerve fibre loss to aid earlier diagnosis, risk stratification and the development of new therapies in our autoimmune patients with severe dry eye.