About Dry Eye Disease

Dry Eye is a multifactorial disease of the tears and ocular surface that results in symptoms of discomfort, visual disturbance, and tear film instability with potential damage to the ocular surface. It is accompanied by increased osmolarity of the tear film and inflammation of the ocular surface.¹

Tears fulfill an essential role in maintaining ocular surface integrity, protecting against microbial challenge, and preserving visual acuity. These functions, in turn, are critically dependent upon the composition, concentration and stability of the tear film structure. Disruption, deficiency, or absence of the tear film can severely impact the eye. Associated disorders can lead to desiccation of the corneal epithelium, ulceration and perforation of the cornea, an increased incidence of infectious disease, and other clinical conditions.²

Concentration of the Tear Film and Osmolarity

Hyperosmolarity has been described in the literature as the primary marker of tear film integrity. When the quantity or quality of secreted tears is compromised (known as aqueous deficient or evaporative Dry Eye Disease), increased rates of evaporation lead to a more concentrated tear film(increased osmolarity) that places stress on the corneal epithelium and conjunctiva.

1."Definition and Classification of Dry Eye. Report of the Diagnosis and Classification Subcommittee of the Dry Eye Workshop (DEWS)." The Ocular Surface 5(2): 75-92, 2007.

2. Sullivan DA, Dartt DA, et al. Lachrymal Gland, Tear Film, and Dry Eye Syndromes 2: Basic Science and Clinical Relevance. Advances in Experimental Medicine and Biology. 1998;438.