Dry eye and systemic diseases.

Tear film instability and reduced tear production initiate a vicious circle where hyperosmolarity, ocular inflammation, and apoptosis may induce a damage of the ocular surface including keratitis which is all included in a common condition called dry eye disease (DED). DED can be apparently an isolated ocular surface condition; however, multiple ocular and systemic risk factors have been identified. The association with systemic diseases such as autoimmune diseases, hormonal imbalance, dietary imbalance, metabolic diseases, infections, psychological conditions, and aging together with external causative factors may act independently or interacting each other to initiate and/or perpetuate signs and symptoms typical of this very common ocular surface disease. Rheumatological disorders are most typically associated with dry eye; therefore, strict interaction with rheumatologists is important for the diagnosis and management of DED patients. In the present narrative review, we highlight associations between DED and some of the systemic disorders that may be implicated in the development of the disease.