Diagnosis and primary care management of tear film deficiencies.

The tear film is a complex physical and biochemical structure. It functions to lubricate and protect the ocular surface from a variety of insults. Disorders of the tear film can lead to patient complaints as well as observable clinical signs. Combining clinical observations with a knowledge of the dynamic interaction of the tear film and the ocular surface should allow the practitioner to develop a management plan for symptomatic patients. This article details the many tests available for assessing tear film and ocular surface integrity, and discusses means of managing complications.