Lightrino Tear Film Analyzer (TFA) measures the critical thickness of the tear film lipid layer, which is essential for reducing tear evaporation and maintaining tear film stability.
The lipid layer is the outermost, anterior layer of the tear film covering the human cornea. It forms a smooth optical interface between the eye and the ambient environment, which is critical for visual acuity. The real-time measurement of the tear lipids thickness is directly related to the water maintaining capability of the ocular surface, which is a key parameter for dry eye diagnosis.
The lipids are secreted from meibomian glands, which are tubuloacinar, holocrine glands located in the tarsal plates within the upper and lower eyelids. The orifices of the meibomian glands at the eyelid margin are directly visible with a magnifying glass.
The tear film lipid layer is a mixture of about 60~70% non-polar lipids (cholesterol, cholesterol esters, and wax esters), and 30~40% polar lipids (phospholipids and glycolipids). The lipid layer is formed during the upstroke of a blink, where the polar lipids interacting with the aqueous layer, and the non-polar lipids spread with the movement of the polar lipids.
Characterizing tear film lipid layer is a critical step for precise diagnosis of dry eye syndrome.