“The ocular surface complex” is defined as the ocular surface, including the corneal surface with its epithelium, conjunctiva, and its superficial layers and the ocular adnexal system containing the lacrimal, meibomian gland, and eyelashes, among others, and eyelid with its blinking mechanism. The diseases associated with these structures are known as “ocular surface diseases” [4]. Among the ocular surface diseases, dry eye syndrome is the most common. Multiple mechanisms, such as ocular surface and lacrimal gland inflammation, neurotrophic deficiency, and meibomian gland dysfunction (MGD), play significant roles. It had been suggested that one or more of the following initial events may lead to alterations described in the tear film and ocular surface of patients with DM: a) chronic hyperglycemia, b) corneal nerve damage, and c) impairment on insulin action [5].