Evaluation of a New Tear Osmometer for Repeatability and Accuracy, Using 0.5-μL (500-Nanoliter) Samples

Yıldız, Elvin; Fan, Vincent C; Banday, Hina; Ramanathan, Lakshmi; Bitra, Ratna K; Garry, Eileen; Asbell, Penny A.

doi:10.1097/ico.0b013e318198396b

Cited by 22 publications

(12 citation statements)

References 18 publications

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“…84 Other studies have not shown correlation with clinical signs and symptoms. 81,85 Though studies have shown the reliability of some of the available devices using standardized solutions, 74,86,87 this does not necessarily indicate reliability when tears are sampled from the ocular surface. Rather than determining one value, it may be best to repeat measurements for each eye to demonstrate stability or lack of stability, indicative of DED.…”

Section: Point Of Care Biomarkersmentioning

confidence: 99%

The Growing Need for Validated Biomarkers and Endpoints for Dry Eye Clinical Research

Roy

Wei

Kuklinski

et al. 2017

Invest. Ophthalmol. Vis. Sci.

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PurposeBiomarkers with minimally invasive and reproducible objective metrics provide the key to future paradigm shifts in understanding of the underlying causes of dry eye disease (DED) and approaches to treatment of DED. We review biomarkers and their validity in providing objective metrics for DED clinical research and patient care.MethodsThe English-language literature in PubMed primarily over the last decade was surveyed for studies related to identification of biomarkers of DED: (1) inflammation, (2) point-of-care, (3) ocular imaging, and (4) genetics. Relevant studies in each group were individually evaluated for (1) methodological and analytical details, (2) data and concordance with other similar studies, and (3) potential to serve as validated biomarkers with objective metrics.ResultsSignificant work has been done to identify biomarkers for DED clinical trials and for patient care. Interstudy variation among studies dealing with the same biomarker type was high. This could be attributed to biologic variations and/or differences in processing, and data analysis. Correlation with other signs and symptoms of DED was not always clear or present.ConclusionsMany of the biomarkers reviewed show the potential to serve as validated and objective metrics for clinical research and patient care in DED. Interstudy variation for a given biomarker emphasizes the need for detailed reporting of study methodology, including information on subject characteristics, quality control, processing, and analysis methods to optimize development of nonsubjective metrics. Biomarker development offers a rich opportunity to significantly move forward clinical research and patient care in DED.OverviewDED is an unmet medical need — a chronic pain syndrome associated with variable vision that affects quality of life, is common with advancing age, interferes with the comfortable use of contact lenses, and can diminish results of eye surgeries, such as cataract extraction, LASIK, and glaucoma procedures. It is a worldwide medical challenge with a prevalence rate ranging from 8% to 50%. Many clinicians and researchers across the globe are searching for better answers to understand the mechanisms related to the development and chronicity of DED. Though there have been many clinical trials for DED, few new treatments have emerged over the last decade. Biomarkers may provide the needed breakthrough to propel our understanding of DED to the next level and the potential to realize our goal of truly personalized medicine based on scientific evidence. Clinical trials and research on DED have suffered from the lack of validated biomarkers and less than objective and reproducible endpoints. Current work on biomarkers has provided the groundwork to move forward. This review highlights primarily ocular biomarkers that have been investigated for use in DED, discusses the methodologic outcomes in providing objective metrics for clinical research, and suggests recommendations for further work.

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Section: Point Of Care Biomarkersmentioning

confidence: 99%

The Growing Need for Validated Biomarkers and Endpoints for Dry Eye Clinical Research

Roy

Wei

Kuklinski

et al. 2017

Invest. Ophthalmol. Vis. Sci.

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“…22 The Advanced Instruments Nanoliter Osmometer (Advanced Instruments, Inc, Norwood, MA), although less cumbersome, was also hampered by the manipulation of small quantities of tear with micropipettes. 21 The Wescor vapor pressure osmometer (Wescor, Inc, Logan, UT) was easy to use for larger volumes of fluid but not reproducible for small samples of clinically obtainable tears, 23,24 The TearLab instrument (TearLab, Inc, San Diego, CA) accurately measures osmolarity of 50 nanoliter microvolumes of tears in a rapid assay based upon lab-on-a-chip measurement of electrical impedance/conductance. 9 The TearLab instrument is most adaptable to use in the clinic setting and has received Food and Drug Administration clearance for such use.…”

Section: Introductionmentioning

confidence: 99%

New Testing Options for Diagnosing and Grading Dry Eye Disease

Foulks

Pflugfelder

2014

American Journal of Ophthalmology

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PURPOSE To describe new options for diagnosis and severity grading of dry eye disease DESIGN Perspective on technological advancements to identify tear dysfunction and their value in diagnosing and grading dry eye disease. METHODS Evidence is presented on new and evolving technologies to measure tear stability, composition and meniscus height and their role in dry eye diagnosis and therapeutic efficacy grading is assessed. RESULTS Evolving concepts regarding pathogenesis and new technologies to evaluate the tears and ocular surface have improved the ability to diagnose, classify and grade the severity of dry eye disease. New technologies include noninvasive imaging of tear stability and tear meniscus height as a measure of tear volume and tear composition (osmolarity, lacrimal factors, inflammatory mediators, growth and differentiation factors). Approved tests, such as tear osmolarity and tear imaging, are being integrated into clinical practice and may eventually supplant certain traditional tests that have greater variability and less sensitivity. Other tests, such as molecular assays of tears and conjunctival cells are currently being used in studies investigating pathogenesis and therapeutic mechanism of action. They may eventually translate to routine clinical practice. CONCLUSIONS New technologies have emerged that can noninvasively evaluate the tears and measure disease-associated compositional changes. These tests are being integrated into clinical practice and therapeutic trials for diagnosis, classification and severity grading of dry eye disease.

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“…The Advanced Tear Osmometer (Advanced Instruments, Norwood, Massachusetts)10 uses freezing-point depression, whereas the TearLab11 (Ocusense, San Diego, California) uses electrical impedance12 to measure osmolarity. The Advanced Tear Osmometer is less practical for clinical use owing to some of its operational features.…”

Section: Introductionmentioning

confidence: 99%