Osmolarity of Tear Microvolumes in Keratoconjunctivitis Sicca

Gilbard, Jeffrey P.; Farris, R. Linsy; Santamaria, Jaime

doi:10.1001/archopht.1978.03910050373015

Cited by 342 publications

(191 citation statements)

References 16 publications

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“…5,7 In PEX syndrome, lower scores in the Schirmer and tear break-up time tests were found to be secondary conjunctival involvement. 4 The value of measuring tear osmolarity in diagnosing dry eye disease and its potential to be the gold standard diagnostic test was proposed a long time ago; 8,9 however, problems associated with existing technologies hindered the use of such a test in clinical practice. Despite the technical challenges to measure osmolarity in a laboratory, many papers have confirmed the value of tear osmolarity evaluation in the diagnosis of dry eye.…”

supporting

confidence: 44%

Tear osmolarity in unilateral pseudoexfoliation syndrome

Öncel

Pınarcı

Akova

2012

Clinical and Experimental Optometry

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Purpose:The aim was to evaluate tear osmolarity of patients with clinically unilateral pseudoexfoliation (PEX) syndrome and to compare the values with otherwise normal subjects. Methods: Sixty-two eyes of 31 patients with unilateral PEX syndrome and 31 eyes of 31 normal subjects were studied. The TearLab osmolarity system (OcuSense, Inc, San Diego, CA, USA) was used to measure tear osmolarity. Eyes were grouped as normal eyes of patients having unilateral PEX syndrome (group A), eyes of patients having unilateral PEX syndrome with deposits of PEX material (group B) and eyes of normal subjects (group C). Differences in tear osmolarity were compared among groups A, B and C. Independent t-tests and paired t-tests were used for statistical analysis. Results: The mean tear osmolarity was 298.7 Ϯ 7.8 mOsm/l (range 285 to 306) in the control group (group C), 306.3 Ϯ 6.6 mOsm/l (range 290 to 314) in the eyes of patients having PEX syndrome with deposits of pseudoexfoliative material (group B) and 301.4 Ϯ 7.1 mOsm/l (range 284 to 305) in the fellow eye of these patients (group A). There was a significant difference between tear osmolarity of groups C and B (independent t-test, p = 0.011). Also, there was a significant difference between the osmolarity of each eye of patients with unilateral PEX syndrome (groups A and B) (paired t-test, p = 0.001). The difference between tear osmolarity of groups A and C was not statistically significant (independent t-test, p = 0.146). Conclusion: In conclusion, tear osmolarity is higher in both eyes of patients when compared with normal subjects, using the independent t-test (although highest in clinically positive eyes of these patients). Both eyes of patients having PEX syndrome could be more prone to the development of dry eye syndrome.

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confidence: 44%

Tear osmolarity in unilateral pseudoexfoliation syndrome

Öncel

Pınarcı

Akova

2012

Clinical and Experimental Optometry

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“…Osmolarity scores were variable and inconclusive. However, the association between dry eye and elevated tear film osmolarity has been evaluated and confirmed by numerous studies; Gilbard et al [35] reported this association as early as 1978. Lemp et al [36] reported that tear film osmolarity is the best single means of diagnosing and classifying dry eye disease.…”

Section: Discussionmentioning

confidence: 43%

The ONIT Study–Ocular Nutrition Impact on Tear Film

Mulqueeny¹

2015

AOVS

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Purpose: To better understand the role of a proprietary dietary supplement formulated to contain Omega 3 and seven other anti-inflammatories plays in patients with established clinical findings consistent with dry eye disease. Secondarily, this evaluation will attempt to discover if any of the diagnostic markers are predictive to the therapeutic approach of omega 3 anti-inflammatory dietary supplements. Design:Clinical-based, multi-center cohort study. Methods:This eight-week feasibility study was to determine if subjects presenting with dry eye confirmed by diagnostic markers and symptoms responded to nutritional therapy via an oral nutritional supplement (EyePromise EZ Tears™). Analyses were completed on a subgroup of subjects with 4 of 7 possible diagnostic criteria.Results: A total of 67 patients were enrolled between 18-79 years of age inclusive. At the conclusion of the study, improvement from baseline was demonstrated in OSDI decreasing scores by 38%. Improved tear breakup time and phenol red thread scores were seen and was reduced conjunctival staining. There was also a decrease noted in lid inflammation. Osmolarity scores were variable and inconclusive. Conclusion:Supplementation with this Omega-3 anti-inflammatory product in dry eye showed significant improvement in OSDI, TBUT, conjunctival staining lid inflammation and phenol red tear meniscus and corneal staining scores. This decrease in patient symptoms could be an indication of decreasing ocular surface inflammation and possible stabilization of the lipid layer. The change from baseline for these signs appears to be rapid, as differences were shown as early as one-week post-supplementation.

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“…Later, samples as small as 5 ml from a single eye were measured with a dew point-depression method (Mastman et al 1961;Terry & Hill 1978). Gilbard et al (1978) used a freezing point depression method requiring sample volumes of only a few tenths of a cubic millimeter (0.1 to 0.3 ml). The actual fluid volume from the sample that could be processed for a single measurement was approximately 7 nanoliters.…”

Section: Discussionmentioning

confidence: 48%

“…The freezing point depression ''nanoliter osmometer'' is the current ''gold standard'' (Farris 1994) for assessing the osmolality of tear fluid due to its accuracy (within 2%) on small volumes of 0.2 microliter (ml) (White et al 1993a). A submicrovolume requirement allows an adequate volume of basal tears to be obtained rapidly and reliably from subjects without as much risk of reflex contamination which can result in decreased osmolality readings (Gilbard et al 1978;Benjamin & Hill 1983;White et al 1993a).…”

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confidence: 43%

Vapor pressure osmometry, Minimum sample microvolumes

Pensyl

Benjamin

1999

Acta Ophthalmologica Scandinavica

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ABSTRACT.Purpose: Vapor pressure osmometers are currently designed to handle sample volumes as small as 2.0 microliters (ml) but smaller sample volumes are desirable in tear fluid studies. We determined the minimum sample size required for adequate validity and repeatability of osmolality measurements. Methods: A standard saline solution (290 mmol/kg) was sampled by a variable, calibrated pipette. Forty samples were processed with a Wescor 5520 vapor pressure osmometer at each of the following volumes: 2.0, 1.6, 1.2, 1.0, 0.8, 0.7, 0.6 and 0.5 ml. Prior to each test series, the instrument was calibrated with the identical volume of 290 mmol/kg saline. Relevant descriptive statistics were computed and an analysis of variance (ANOVA) was performed on the resulting data. Results: The mean osmolalities of the eight 40-sample groups ranged from 288.42 to 290.68 mmol/kg and were not significantly different from 290 mmol/ kg or each other (p±0.05). The standard deviations were inversely correlated with the sample volumes, gradually increased to approximately 1% as sample volume was reduced to 0.8 ml, then more rapidly increased as the sample volume was lowered still further. Conclusion: Sample microvolumes as small as 0.8 ml can be collected for accurate and repeatable results with the Wescor 5520 vapor pressure osmometer when a standard deviation of approximately 1% is acceptable. Microvolumes from 0.7 to 0.5 ml may also be used if the expanded spread of data can be offset by multiple repeated readings. Using a 2.0 ml sample volume, the ultimate accuracy and repeatability of the Wescor vapor pressure osmometer was ∫2% at 290 mmol/kg: 99% of all readings (∫3 standard deviations) should fall within ∫6 mmol/kg of the true value.

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Osmolarity of Tear Microvolumes in Keratoconjunctivitis Sicca

Cited by 342 publications

References 16 publications

Tear osmolarity in unilateral pseudoexfoliation syndrome

Tear osmolarity in unilateral pseudoexfoliation syndrome

The ONIT Study–Ocular Nutrition Impact on Tear Film

Vapor pressure osmometry, Minimum sample microvolumes

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