Variability of Tear Osmolarity Measurements With a Point-of-Care System in Healthy Subjects—Systematic Review

Baenninger, Philipp B.; Voegeli, Susanne; Bachmann, Lucas M.; Faes, Livia; Iselin, Katja; Kaufmann, C.; Thiel, Michael

doi:10.1097/ico.0000000000001562

Cited by 26 publications

(29 citation statements)

References 55 publications

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“…That average was slightly higher than in some earlier studies and lower than others. [ 37 ] The I-PEN tear osmolarity from 65 readings recorded at 25.2°C ranged from 286.6 to 298.2 mOsm/L with a mean of 294.1 ± 2.3 mOsm/L and a coefficient of variation of 0.78% which is slightly lower compared to the mean (303.8 ± 4.8 mOsm/L) obtained for the current study. [ 25 ] In the current study, the difference between the repeated osmaolrity measurements was up to 40.7 mOsm/L, which is consistent with the literature.…”

Section: Discussioncontrasting

confidence: 58%

“…The reported average tear osmolarity measured using the I-PEN or TearLab osmolarity systems was 288.3–336.4 ± 7.6–22.0 mOsm/L. [ 12 25 37 ] In the current study, there were no significant differences among the three I-PEN readings. The average for the tear film osmolarity readings using the I-PEN osmolarity system was 303.8 ± 4.8 mOsm/L.…”

Section: Discussionmentioning

confidence: 57%

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Investigation of the repeatability of tear osmolarity using an I-PEN osmolarity device

Fagehi

Al-Bishry

Alanazi

et al. 2021

Taiwan J Ophthalmol

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PURPOSE: To investigate the repeatability of tear osmolarity in healthy Saudi subjects using an I-PEN osmolarity device. MATERIALS AND METHODS: Thirty typical male subjects with healthy eyes (27.4 ± 4.9 years) participated in the study. Eye abnormalities were tested with a slit lamp, and eye comfort was determined with the surface disease index. Measurements of the tear break-up time and phenol red thread tests were used for as exclusion criteria. The tear osmolarity test, using an I-PEN osmolarity system, was performed three times in the right eye of each subject with a 5 min' gap between tests. RESULTS: The average osmolarity test score was 303.8 ± 4.8 mOsm/L. Tear osmolarity measurements showed tear osmolarity of 280–299 mOsm/L, 300–309 mOsm/L, and 310–329 mOsm/L in 14 (46.7%), three (10%), and 13 (43.3%) subjects, respectively. Correlations among the three I-PEN measurements were significant (Spearman's correlation coefficient; r = 0.036, 0.501, and 0.603; P = 0.050, 0.006, and 0.001, respectively). The mean coefficient of variance among the three measurements was 4.4%. CONCLUSION: The mean measurement of an I-PEN tear osmolarity was 303.8 ± 4.8 mOsm/L which is in agreement with the range of those reported for healthy subjects. The I-PEN is reliable and has the advantage of portability (hand-held) compared to the other osmolarity systems.

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Section: Discussioncontrasting

confidence: 58%

Section: Discussionmentioning

confidence: 57%

Investigation of the repeatability of tear osmolarity using an I-PEN osmolarity device

Fagehi

Al-Bishry

Alanazi

et al. 2021

Taiwan J Ophthalmol

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“…Changes in concentration of electrolytes and proteins in the muco-aqueous layer, an insufficient or unstable tear film, increased tear evaporation rates are all postulated to contribute to hyperosmolarity of the tear film. A range of osmolarity of 308 mOsm/L to >316 mOsm/L is used as a cutoff for diagnosing DED ( 27 – 30 ). Given the variability, it has been observed that tear hyperosmolarity is not evident in all dry eye patients.…”

Section: Tearsmentioning

confidence: 99%

Review of Biomarkers in Ocular Matrices: Challenges and Opportunities

et al. 2019

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Biomarkers provide a powerful and dynamic approach to improve our understanding of the mechanisms underlying ocular diseases with applications in diagnosis, disease modulation or for predicting and monitoring of clinical response to treatment. Defined as measurable indicator of normal or pathological processes, biomarker evaluation has been used extensively in drug development within clinical settings to better comprehend effectiveness of treatment in ocular diseases. Biomarkers in the eye have the advantage of access to multiple ocular matrices via minimally invasive methods. Repeat sampling for biomarker assessment has enabled reproducible objective measures of disease process or biological responses to a drug treatment. This review describes the usage of biomarkers with respect to four commonly sampled ocular matrices in clinic: tears, conjunctiva, aqueous humor and vitreous. Issues that affect the evaluation of biomarkers are discussed along with opportunities to leverage biomarkers such that ultimately, they can be used for customized targeted therapy.

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“…On the one hand, the best cut-off value for DED (dry eye disease) has been suggested to be 317 mOsmol/L [7]. This despite the awareness of a high variability in the results when measuring tear film osmolarity [8] and increasing opinions that osmolarity itself as a biomarker might not be sensitive enough to differ between healthy eyes and patients with dry eye disease, just as suggested earlier [9]. On the other hand, has the variability of osmolarity being interpreted as a hallmark of dry eye disease, although this could be possibly influenced by the collection method [10].…”

Section: Introductionmentioning

confidence: 99%

Osmokinetics: Defining the Characteristics of Osmotic Challenge to the Ocular Surface

Setten

2020

Klin Monbl Augenheilkd

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The association of severe dry eye disease with elevated osmolarity in the tear film is a subject of ongoing discussions. As the absolute value of osmolarity in tear film is highly variable, the daily variation in osmolarity (DVO) has recently been proposed to further identify the osmotic stress at the ocular surface. However, the DVO alone does not explain the variations in the available published data or allow their use in diagnostic testing or therapy. We therefore investigated and evaluated further details of osmokinetics and their importance for ocular surface disease on the basis of the available literature. Additionally, osmolarity was measured in the tear samples of volunteers in the morning hours between 8 – 10 a. m., midday noon–2 p. m., and afternoon between 3 – 5 p. m., i.e., during normal office hours. The results were compared with available published data which suggested that within the DVO, the daily maximal amplitude of osmotic variation (M-DVO) and the frequency of osmotic cycles (defined as daily osmolarity cycles, DOC) could be the main factors that further characterize osmokinetics. In addition, a decisive role could be the level of osmolarity at which the variation does occurs (L-DVO). The possible effects of these characteristics on ocular surface pathophysiology are discussed, along with their relationship to topical therapy with hypo-osmolar solutions, and the model of the osmotic roller coaster is introduced.

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Variability of Tear Osmolarity Measurements With a Point-of-Care System in Healthy Subjects—Systematic Review

Abstract: There is a high variability of osmolarity measurements with the TearLab system. A substantial number of healthy subjects fulfill the DEWS's definition of DED. We propose interpreting the TearLab osmolarity results cautiously and in the context of other established methods.

Cited by 26 publications

References 55 publications

Investigation of the repeatability of tear osmolarity using an I-PEN osmolarity device

Investigation of the repeatability of tear osmolarity using an I-PEN osmolarity device

Review of Biomarkers in Ocular Matrices: Challenges and Opportunities

Osmokinetics: Defining the Characteristics of Osmotic Challenge to the Ocular Surface

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