TearLab Osmolarity System


The TEARLAB is the first objective and quantitative test for diagnosing and managing dry eye patients. The TearLab Osmolarity System is intended to measure the osomolarity of human tear to aid in the diagnosis of dry eye disease in patients suspected of having dry eye disease, in conjunction with other methods of clinical evaluation.


The TearLab Osmolarity Test Card, in conjunction with theTearLabOsmolarity System, provides a quick and simple method for determining tear osmolarity using nanoliter (nL) volumes of tear fluid collected directly from the eyelid margin. The Test Card is held by the Osmolarity Test Pen, for safe collection.

The TearLabOsmolarity Test utilizes a temperature-corrected impedance measurement to provide an indirect assessment of osmolarity. After applying a lot-specific calibration curve, osmolarity is calculated and displayed as a quantitative numerical value.


TearLab monitors accuracy of its tear osmolarity test at every customer site, in an on-going Phase IV post-market surveillance activity.
The use of NIST traceable control solution with an exact osmolarity of 338 mOsm/L – indicative of a patient with moderately severe dry eye disease – TearLab measures accuracy and precision data on each of its instruments in the physician’s office. Each instrument is tested 10 times in a row with the high control solution. The results of 10-tests will provide (1) accuracy, or how close to the 338 mOsm/L target the instruments actual read, and (2) precision, or how variable the 10 measurements are from each other.