The TearLab Osmolarity System is the first objective and quantitative test for diagnosing and managing Dry Eye patients.
The TearLab Osmolarity System is intended to measure the osmolarity of human tears 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. TearLab is for professional in vitro diagnostic use only.
Hyperosmolarity has been described in the literature as a primary marker of tear film integrity. When the quantity or quality of secreted tears is compromised (known as aqueous deficient or evaporative Dry Eye Disease), increased rates of evaporation lead to a more concentrated tear film (increased osmolarity) that places stress on the corneal epithelium and conjunctiva.
TearLab, is the first objective and quantitative measurement for diagnosing and managing Dry Eye Disease.
A number makes a difference to patients. The osmolarity data allows patients to understand their level of disease.
What does TearLab Osmolarity tell me?
Abnormal tear osmolarity is a failure of homeostatic osmolarity regulation. Elevated osmolarity can cause less regulation of the tear film, more damage to the ocular surface, and more inflammation.
Based on the results of a 300 patient trial that was presented at the 2009 American Academy of Ophthalmology, osmolarity was found to have correctly identified 88% of normal subjects, 75% of mild/moderate disease subjects, and 95% of severe disease subjects at a diagnostic cut-off of 308 mOsms/L.1 Therefore, osmolarity values above 308 mOsms/L are generally indicative of dry eye disease.
It is important to note that this study demonstrated that TearLab outperformed both Schirmer's testing and corneal staining with respect to the ability to correctly identify mild to moderate dry eye patients. 2
Because DED is bilateral, but sometimes asymmetrical, the higher of the two eyes should be used for diagnosis.
As with all diagnostic tests, no number can replace your clinical judgment.
1 Foulks GN, Lemp MA, Berg M, Bhola R, Sullivan BD. TearLab™ Osmolarity as a Biomarker for disease severity in mild to moderate dry eye disease. American Academy of Ophthalmology PO382, 2009
2 Sullivan BD et al., "Diagnostic performance of osmolarity combined with subset markers of dry eye disease in an unstratified patient population". ARVO 2010.
The TearLab Osmolarity Test Card, in conjunction with the TearLab Osmolarity 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 TearLab Osmolarity 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.
To learn how to perform the test, go to Training Videos on this website.
TEARLAB OSMOLARITY SYSTEM READER
The Reader is a portable countertop unit that calculates and displays the osmolarity test result. The Reader automatically converts the tear fluid sample data into an osmolarity measurement and displays the reading on the LCD.
TEARLAB OSMOLARITY SYSTEM PEN
The Pen is designed to hold the Test Card and facilitate safe, simple tear fluid collection. Powered by a permanent rechargeable battery, the Pen provides a mechanical/electrical interface to convey data to the Reader automatically when docked.
TEARLAB OSMOLARITY TEST CARD
Each Test Card is a single-use, individually packaged, nonsterile, polycarbonate microchip. Designed to work in conjunction with the TearLab Pen, the Test Card does not contain chemicals or reagents, and collects tear fluid in less than thirty seconds.
TEARLAB ELECTRONIC CHECK CARDS
Two identical, blue reusable Electronic Check Cards are provided as a procedural quality control to confirm the function and calibration of the TearLab Osmolarity System within manufacturer specifications.
TEARLAB CONTROL SOLUTIONS
TearLab Osmolarity Control Solution is a quality control material used for verifying the quantitative performance of TearLab Osmolarity Test Cards when used with the TearLab Osmolarity System.