System to measure tear film osmolarity aids clinical testing

Louisville, KY-Results of a study evaluating new technology for in-office measurement of tear film osmolarity (TearLab Osmolarity System, TearLab Corp.) show that it outperforms more traditional assessments in identifying dry eye disease and rating disease severity, said Gary N. Foulks, MD.

With the patients categorized as normal or into dry eye disease severity subgroups of mild/moderate and severe based on a composite scoring system integrating the six assessments and using continuous variable analysis, tear film osmolarity performed best in discriminating the normal subjects and was the only measure that demonstrated significant correlation to disease severity among patients with mild/moderate dry eye disease.

"These findings support the use of this new technology as an adjunct to existing methods to aid in the diagnosis and management of dry eye disease," he added.

Measurement of tear osmolarity was identified in the 1995 National Eye Institute/ Industry Dry Eye Workshop and later in the 2007 Report of the International Dry Eye Workshop (DEWS) as a critical factor in both identifying dry eye disease and understanding the mechanisms of how this condition leads to ocular surface damage.

Previously, however, the methods used for measuring tear film osmolarity were complicated, and therefore this assessment was restricted to a research-based procedure, Dr. Foulks said.

"[The system] is lab-on-a-chip technology that enables easy, rapid, and accurate assessment of tear film osmolarity in a clinical setting, and it has the potential to become a useful in-office procedure for diagnosing dry eye and guiding therapeutic selection and response," he said.