Lifitegrast sodium is primarily used in the treatment of dry eye disease. It works by reducing inflammation on the surface of the eye, which is a common issue in this condition. The medication is administered as an ophthalmic solution, applied directly to the eyes. It is particularly effective for patients who have not responded well to other forms of treatment or artificial tears. By inhibiting the interaction of certain proteins that contribute to inflammation, lifitegrast sodium helps alleviate symptoms such as eye discomfort, dryness, and visual disturbances. This makes it a valuable option for improving the quality of life for individuals suffering from chronic dry eye disease.