Dry Eye Disease (DED) is a multi-factorial condition that is difficult to diagnose, in part due to the limitations of objective and subjective testing methodologies. Currently, eye care providers utilize several different tests (some of which are invasive) to measure DED signs (objective) and symptoms (subjective); however, they often show little correlation.
DED is either caused by decreased tear production or increased tear film evaporation. Both phenomena are associated with the volume and composition of the aqueous sublayer of the tear film. There are currently NO single noninvasive methods which can accurately and objectively measure all relevant tear film sublayers including the aqueous sublayer.
Dry eye disease is a common condition that occurs when your tears aren’t able to provide adequate lubrication for your eyes. Tears can be inadequate and unstable for many reasons. For example, dry eyes may occur if you don’t produce enough tears or if you produce poor-quality tears. This tear instability leads to inflammation and damage of the eye’s surface.
Dry eyes feel uncomfortable, but the disease is progressive and can lead to vision quality loss or unbearable pain when opening your eyes. Dry eyes experience may worsen in certain situations, such as on an airplane, in an air-conditioned room, while riding a bike, or after looking at a computer screen for a few hours.
Signs and symptoms, which usually affect both eyes, may include:
Dry eyes are caused by a variety of reasons that disrupt the healthy tear film. Your tear film has two layers: a main mixed layer of mucus in aqueous and an overlayed layer of fatty oils. This combination normally keeps the surface of your eyes lubricated, smooth, and clear. Problems with any of these layers can cause dry eyes. Reasons for tear film dysfunction are many, including hormone changes, autoimmune disease, inflamed eyelid glands, or allergic eye disease. For some people, the cause of dry eyes is decreased tear production or increased tear evaporation
Anyone can get dry eyes, but a patient might be more likely to have a dry eye if:
Currently, it is believed that more than 300M people suffer from dry eye disease on a global basis. Improved assessment of the tear film structure and its deficiencies will enable medical professionals to better monitor and tailor the dry eye treatments to the individual patient.