The recently published 2017 TFOS DEWS II report on Dry Eye Disease (DED) reflects the huge progress that has been made in DED diagnosis and treatment since the report was first issued a decade ago. Of particular interest to us at Visiometrics was the finding that “DED implies major changes to the tear film structure and function, which are associated with this disease,” as well as the committee’s call for tear film measurement methods that are objective, noninvasive and dynamic. The ability of our HD Analyzer to assess tear film function in a way that meets all three criteria is the reason why many leading dry eye specialists have incorporated it into their DED diagnosis and treatment protocols.
The OSI (Optical Scatter Index) produced by the HD Analyzer quantifies a patient’s quality of vision. As noted in the DEWS II report, image quality “is directly related to the quality of the tear film.” These measurements do not rely on patient feedback or clinician interpretation, removing subjectivity from the process.
During an HD Analyzer exam, measurements are taken without interfering with natural tear film function. No fluorescein, which can alter the tear film composition, is required. This ensures the most reliable results with minimal patient discomfort.
Tear film breakup is a dynamic process, so it naturally follows that the most accurate results can be obtained by measuring the tear film over time. By measuring fluctuation in quality of vision over a 20 second period, the HD Analyzer can determine the stability of a patient’s tear film.
The HD Analyzer not only aids in dry eye diagnosis, it is also extremely valuable in assessing the results of a treatment protocol. The Mean OSI and graphical plotting of OSI Evolution with Time (over the 20 second test period) provide objective data points for comparison from one patient visit to the next. With successful treatment, the OSI RANGE will decrease and the “OSI evolution with time line” (represented in the graphics above) becomes flatter.
The understanding of the mechanisms underlying dry eye continue to evolve, thanks to the work of the Tear Film and Ocular Surface Society. It’s exciting to be offering DED technology that is on the leading edge of that evolution.