Blepharitis of the eyelid margins. Posterior blepharitis and Meibomian gland dysfunction are frequently associated with rosacea and can be seen during an ocular examination of the posterior eyelid margin. The Meibomian glands may appear caked with oil or visibly obstructed. Cultures of the eyelid margins can be a clear indicator for patients suffering from recurrent anterior blepharitis with severe inflammation, in addition to patients who are not responding to therapy. Measurements of tear osmolarity may be beneficial in diagnosing concurrent dry eye syndrome (DES), which may be responsible for overlapping symptoms and would allow the physician to decipher between conditions and
Sebaceous gland due to heightened levels of androgens. Sebaceous glands secrete the oily, waxy substance called "sebum" () that is made of triglycerides, wax esters, squalene, and metabolites of fat-producing cells. Sebum waterproofs and lubricates the skin and hair of mammals. Sebaceous secretions in conjunction with apocrine glands also play an important thermoregulatory role. In hot conditions, the secretions emulsify the sweat produced by the eccrine glands and this produces a sheet of sweat that is not readily lost in drops of sweat. This is of importance in delaying dehydration. In colder conditions, the nature of sebum becomes more lipid and in