Abstract
Abstract: :
Purpose: Lipid tear film stabilizes the tears by lowering the surface tension and preventing aqueous tear evaporation, and may be analyzed by kinetic analysis of tear interference images. This study investigated changes of lipid film following application of a new emulsion-based eye drop (REFRESH ENDURATM, Allergan, Inc.) in normal subjects and patients with dry eyes. Methods: Five normal subjects and 10 aqueous tear deficient (ATD) patients received a complete eye examination including symptom score, tear breakup time, dye staining, and fluorescein clearance test. One eye received a single dose of emulsion eye drop (EED), while the other eye received nonpreserved saline (NPS) as a control. Kinetic analysis of tear interference images taken by DR-1® (Kowa, Japan) was performed before and at various times after instillation of the drops. Results: Compared with the control, all eyes receiving EED showed rapid restructuring of the pre-existing lipid film. In normals, restructuring resulted in a thick lipid band across the cornea and a significant increase of the lipid film thickness. For ATD patients, EED application resulted in either a scant, irregular tear film, which became covered by the lipid film, or a modified lipid film changed without forming a band or irregularities. EED tended to be more comfortable in patients with more severe ATD. Kinetic analysis showed that the mean spread time improved for all cases after EED when compared with baseline or with control (P < 0.05). Conclusions: EED produces significant changes in the tear film of normal and dry eye patients. Further investigation with a prolonged period of treatment is warranted to establish whether EED might help improve the spread and thickness of the lipid tear film in moderate and severe dry eyes.
Keywords: cornea: tears/tear film/dry eye • cornea: epithelium • cornea: clinical science