Clinical Trial: TearLab Core Validation Study to Establish Referent Values for Dry Eye Disease

Study Status: Completed
Recruit Status: Completed
Study Type: Observational

Official Title: A Prospective Study to Establish Normative Values, Demographic Variations, Referent Diagnostic Values and Disease Severity Correlations for Dry Eye Disease and TearLab Osm

Brief Summary: This is a prospective, observational case series to determine the clinical utility of tear osmolarity and other commonly used objective tests to diagnose dry eye disease, as well as to establish referent values for objective tests of the disease.

Detailed Summary: This is a prospective, observational case series to determine the clinical utility of tear osmolarity, tear film breakup time, corneal fluorescein staining, conjunctival lissamine green staining, Schirmer's test without anesthesia, Bron/Foulks meibomian glan grading and the ocular surface disease index to diagnose dry eye disease, as well as to establish referent values for objective tests of the disease. Patients were recruited across sites in the EU and US from the general clinical population.
Sponsor: TearLab Corporation

Current Primary Outcome:

  • Diagnostic Test Data for Disease Using Tear Osmolarity Threshold > 308 mOsm/L [ Time Frame: Single visit ]

    Tear osmolarity was measured with a laboratory-on-a-chip, to simultaneously collect and analyze the electrical impedance of a 50 nL tear sample from the interior lateral meniscus (TearLab Osmolarity System). A cutoff threshold of more than 308 mOsm/L was used for differentiating normal from mild to moderate subjects.

    The clinical tools most commonly used in grading dry eye severity are symptomatology (e.g. questionnaires such as the Ocular Surface Disease Index (OSDI) or McMonnies Dry Eye Questionnaire), tear osmolarity, tear film breakup time (TBUT), fluoresceine or lissamine green staining of the cornea and conjunctiva, meibomiam secretion scoring, and the Schirmer test.To convert all the various clinical measurements into a common unit system, based on their breakpoints provided by the Dry Eye Workshop (DEWS), a composite score was created. Its scale being between 0 (representing the least evidence of disease) and 1 (representing the most evidence of disease).

  • Diagnostic Test Data for Disease Using Schirmer Test Threshold < 7 mm [ Time Frame: Single visit ]

    A 5-minute Schirmer test was performed with sterile strips without anesthetic (Tear Flo). The cutoff threshold of <7mm was used to differentiating normal from mild subjects.

    The clinical tools most commonly used in grading dry eye severity are symptomatology (e.g. questionnaires such as the Ocular Surface Disease Index (OSDI) or McMonnies Dry Eye Questionnaire), tear

    Original Primary Outcome: To establish OcuSense TearLab Osmometry (OTO) normative values, and referent values to diagnose dry eye disease (DED) [ Time Frame: Single site visit ]

    Current Secondary Outcome:

    • Referent Values for Tear Osmolarity [ Time Frame: Single visit ]
    • Referent Values for Schirmer Test [ Time Frame: Single visit ]
    • Referent Values for Tear Film Breakup Time [ Time Frame: Single visit ]
    • Referent Values for Corneal Staining [ Time Frame: Single visit ]
      Corneal Staining is used to identify and evaluate ocular surface and corneal damages. It was evaluated under cobalt blue illumination 2.5 to 3.0 minutes after fluorescein instillation. Staining amplitude followed the National Eye Institute/Industry Workshop scale. The cutoff threshold >4/15 was used to differentiate normals from dry eye subjects. A score of 0 indicates no damage of ocular surface/cornea, while the maximum for the most severe damage is 15.
    • Referent Values for Conjunctival Staining [ Time Frame: Single visit ]
      Conjunctival staining is used to identify and evaluate dead or injured conjunctival cells. Conjunctival staining was performed 2.5 to 3.0 minutes after instillation of 10 μL of a 1% sodium lissamine green dye. Conjunctival staining followed the National Eye Institute/Industry Workshop scale. A cutoff threshold of grade >3/12 was used to differentiate normal from dry eye subjects. A score of 0 indicates no damage of conjunctival cells, while the maximum for the most severe damage is 12.
    • Referent Values for Meibomian Gland Grading [ Time Frame: Single visit ]
      Meibomian gland dysfunction was assessed to grade the quality, expressibility, and volume of gland secretion, according to Bron/Foulks scoring system. A score of 0 indicates full integrity of these glands while the maximum of 27, is used for severe damage.
    • Referent Values for Ocular Surface Disease Index [ Time Frame: Single visit ]
      Ocular Surface Disease Index (OSDI) Questionnaire was used for symptoms assessment and the index is calculated based on the responses given by the subject. A cutoff of 15/100 score was used to differentiate between normal and dry eye subjects. A score of 0 confirms no dry eye symptoms are present, while a maximum of 100 indicates the maximum severity of symptoms experienced by subjects.


    Original Secondary Outcome:

    • To establish the relationship between OTO values and the severity of DED. [ Time Frame: Single site visit ]
    • To assess the effect on diagnostic accuracy of adding additional categories of diagnostic test results, e.g. Ocular Surface Disease Index (OSDI) and /or Tear Break-up Film Test (TBUT). [ Time Frame: Single Site Visit ]
    • To assess the effect of age and sex on the range of OTO values in normal subjects [ Time Frame: Single site visit ]
    • To establish the variance of right eye (RE)/left eye (LE) OTO values in normal subjects and in subjects with DED [ Time Frame: Single site visit ]
    • To establish the accuracy of single eye OTO values versus bilateral values in diagnosing DED. [ Time Frame: Single Site Visit ]
    • To assess the range of OTO values in symptomatic subjects without signs of DED and in DED subjects of varying severity as judged by the clinical severity scale. [ Time Frame: Single Site Visit ]


    Information By: TearLab Corporation

    Dates:
    Date Received: February 18, 2009
    Date Started: February 2009
    Date Completion:
    Last Updated: April 13, 2016
    Last Verified: April 2016