Reproducibility of Tearfilm Osmolarity Measurements Using TearLab® in Patients With Dry Eye Syndrome and Healthy Subjects

Study Overview
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Brief Summary
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Dry Eye Syndrome (DES) is a common condition that affects approximately 20% of adults aged 45 and older. Although several clinical tests for the diagnosis and monitoring of DES are available, currently no gold standard for the assessment of DES exists. It has, however, been hypothesized that the assessment of tear film osmolarity may be a new and promising approach of an objective and non-invasive method for diagnosis and monitoring of treatment success. Recently, a new commercially available instrument (TearLab®, OcuSens Inc, San Diego, USA) for the assessment of tear film osmolarity has been introduced. This instrument allows for the easy and non-invasive determination of tear film osmolarity. Unfortunately, no data about reproducibility are yet available. Consequently, the current study sets out to investigate the short time reproducibility of tear film osmolarity measurements using the TearLab® instrument.

Official Title
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Reproducibility of Tearfilm Osmolarity Measurements Using TearLab® in Patients With Dry Eye Syndrome and Healthy Subjects

Conditions
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Dry Eye Syndrome

Intervention / Treatment
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* Device: Measurement of tear film osmolarity with the TearLab® instrument
* Other: Schirmer I test
* Other: Tear break up time
* Device: Optical Quality Analysis System
* Other: Ocular Surface Disease Index


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients with dry eye syndrome (DES): Men and Women aged between 45 and 80 years, with DES defined as a pathological Schirmer I test and / or a pathological break-up time test. Schirmer I test and break up time will be tested and analyzed according to the guidelines published in the Report of the International Dry EyeWorkShop (DEWS) 2007 normal findings in the ophthalmic examination other than DES Healthy control group: Men and Women aged between 45 and 80 years, normal findings in the medical history and ophthalmic examination Exclusion Criteria: Abuse of drugs or alcoholic beverages Participation in a clinical trial Symptoms of a clinically relevant illness

Ages Eligible for Study
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Minimum Age: 45 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: 20 patients with dry eye syndrome<br>Patients with dry eye syndrome defined as outlined in the inclusion and exclusion criteria | Device: Measurement of tear film osmolarity with the TearLab® instrument<br> <br> Other: Schirmer I test<br> <br> Other: Tear break up time<br> <br> Device: Optical Quality Analysis System<br>* Measurement of the objective scattering index (OSI)<br>Other: Ocular Surface Disease Index<br> <br> |
| Other: 20 healthy control subjects<br>age- and sex-matched controls | Device: Measurement of tear film osmolarity with the TearLab® instrument<br> <br> Other: Schirmer I test<br> <br> Other: Tear break up time<br> <br> Device: Optical Quality Analysis System<br>* Measurement of the objective scattering index (OSI)<br>Other: Ocular Surface Disease Index<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Coefficient of variation of tear film osmolarity after repeated measurements |  | Measurement of tear film osmolarity 3 times daily within 30 minutes for 3 consecutive days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Subjective symptoms assessed using the OSDI test |  | on the screening day | 
| Tear break up time |  | on 3 consecutive study days once a day | 
| Schirmer I test |  | on 3 consecutive study days once a day | 
| OSI (Objective Scattering Index) |  | on 3 consecutive study days once a day | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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tear film osmolarity, objective scattering index, tear break up time, Schirmer I test