The Tear Film: Pathological Conditions

This chapter first reviews the pathogenesis of dry eye (DE) and the pathological effects DE has on the properties and composition of the tear film, lacrimal and meibomian glands, and goblet cells. Next, the pathologic changes that occur with two DE related risk factors: aging and the use of glaucoma eye drops are discussed. Finally, the clinical consequences of tear film, lacrimal gland, meibomian gland, and goblet cell alterations, focusing on visual function, nerve modulation, quality of life, and economic burden, are explored.