Efficacy of the Chronic Application of Tear Formulations
Recruitment status was: Not yet recruiting
|Dry Eye||Drug: Next Generation Emulsion Drug: Refresh Dry Eye Therapy Drug: Refresh Contacts|
|Study Design:||Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Single Blind (Participant)
Primary Purpose: Treatment
|Official Title:||Therapeutic Efficacy of the Chronic Application of Tear Formulations for Dry Eye and Normal Subjects Under Conditions of Environmental Stress|
- Tear Film Evaporation [ Time Frame: Each subject will be followed for the duration of the study, an expected average of 8-9 weeks ]Tear film evaporation will be determined with a 'Servo-Med EP-Evaporimeter'. This measures the relative humidity and temperature at two sensors separated by a known distance, above the evaporative surface. The ocular surface evaporation will be calculated from measurements of fluid loss with the eyes open and closed while the subject sits with the eye covered by a modified goggle.
- Interferometry [ Time Frame: Each subject will be followed for the duration of the study, an expected average of 8-9 weeks ]The structure and quality of the tear film will be assessed by observing the interference fringes of the lipid layer. Interferometry facilitated with a miniature slow motion video will be used. The grading system developed previously in our laboratory will be utilised to grade the tear film distribution. This grading system classifies the tear film structure on the basis of the distribution of tears after a blink. Measurements are made while the subject sits quietly and looks into the lens of the device.
- Tear Film Osmolarity [ Time Frame: Each subject will be followed for the duration of the study, an expected average of 8-9 weeks ]Tear film osmolarity was measured using an 'OcuSense TearLab Osmometer'. This employs a single use, disposable test card mounted to a collection pen, to obtain a small sample of tear fluid by passive capillary action from the inferior-temporal tear meniscus. The measurement of the electrical impedance is carried out within the pen. The pen is then docked into the reader, which calculates and displays the osmolarity result.
- Non-invasive tear break up time [ Time Frame: Each subject will be followed for the duration of the study, an expected average of 8-9 weeks ]The 'HIR-CAL Grid' system based on a modified Bausch and Lomb keratometer will be used. The 'HIR-CAL Grid'will be focused on the pre-corneal tear film and the time before first distortion of the grid image will be recorded. This will indicate the non-invasive tear break up time. Three measurements will be taken while the subject is instructed to blink and then to hold the eye open while the examiner watches the reflection from the tear film, and the mean calculated.
- Tear sampling and bio-marker analysis [ Time Frame: Each subject will be followed for the duration of the study, an expected average of 8-9 weeks ]
Approximately 1 μl of tears will be collected from the subject's eye using a sterile micropipette.
It will then be diluted in cytokine assay buffer and simultaneously analysed for biomarkers of ocular surface disease (cytokines) using the Luminex Beadlyte assay system. The bio-markers to be studied are included in the Human high sensitivity cytokine/chemokine kit (Millipore). These markers are associated with pro-inflammatory activation and have been previously studied in dry eye and other inflammatory conditions.
|Study Start Date:||July 2011|
|Estimated Study Completion Date:||November 2011|
|Estimated Primary Completion Date:||November 2011 (Final data collection date for primary outcome measure)|
Experimental: Next Generation Emulsion
Next Generation Emulsion Multi-Dose Eye Drop (9963X) is a sterile, buffered, aqueous and emulsion topical ophthalmic product formulated for the relief of ocular surface irritation and symptoms of dryness. The Next Generation Emulsion 9963X formulation is an oil-in-water aqueous emulsion intended to replenish deficient aqueous and lipid components and stabilising the tear film.
Drug: Next Generation Emulsion
One drop both eyes 4 times daily for two weeks
Active Comparator: Refresh Dry Eye Therapy
A preserved multi-dose formulation for use in treating dry eye symptomatology. The key ingredients are Castor oil, Polysorbate 80, Carbomer 1342 and Glycerin. Refresh Dry Eye Therapy® Lubricant Eye Drops contains emulsified castor oil, which enhances the natural oily superficial tear layer on the ocular surface. By stabilizing and supplementing the lipid layer, castor oil may retard evaporation of surface moisture.
Drug: Refresh Dry Eye Therapy
One drop both eyes four times daily for two weeks
Active Comparator: Refresh Contacts
Solution contains carboxymethylcellulose sodium (carmellose), sodium chloride, boric acid, sodium borate, potassium chloride, calcium chloride, magnesium chloride, Purite®, sodium hydroxide, and purified water. This product is registered as a CE Mark medical device. Refresh Contacts Comfort drops providing soothing relief from tired, dry eyes. Although intended for contact lens wearers, the primary indication is for relief of dry eyes as is being studied in this investigation.
Drug: Refresh Contacts
One drop both eyes four times daily for two weeks
Please refer to this study by its ClinicalTrials.gov identifier: NCT01384851
|Contact: Alan Tomlinson, DSc PhD||0044 141 331 ext 3380||A.Tomlinson@gcu.ac.uk|
|Glasgow Caledonian University|
|Glasgow, United Kingdom, G4 0BA|
|Principal Investigator:||Alan Tomlinson, DSc PhD||Glasgow Caledonian University|