[Diagnosis and and differentiation of dry eye disorders]

Artificial tears often fail in dry eye patients. Our goal was to establish a diagnostic approach that involves alternatives that are more effective for the treatment. We examined 110 patients with dry eyes not stabilized by artificial tears: medical history, visual acuity, slit lamp examination, rose bengal stains and fluorescein stains, Schirmer test, break-up time (BUT), dye tests, impression cytology, and lid transillumination. This allowed disturbances of the three layers of the tear film (lipid, aqueous, mucin) to be differentiated. Cellular damage of the ocular surface was evaluated and scored by slit lamp examination, rose bengal staining, and impression cytology. Only 8% of the patients with "sicca syndrome" had exclusive aqueous deficiencies amenable to artificial tears. In contrast, lipid deficiencies (chronic blepharitis) were determined most frequently (78%). Twenty-six percent had disturbances in two or more layers of the tear film. The diagnostic strategy of differentiating disturbances of the layers of the tear film offers a more specific approach to the treatment of dry eyes.