Repeatability and Agreement of Anterior Segment Optical Coherence Tomography (AS-OCT) and Thermography
Dry eye is a common condition that affects vision and quality of life in patients. Dry eye clinical research is limited to follow up of disease progression. Currently, most research outcomes are based on subjective patient complaints rather than objective assessment of the condition. Only few objective measurements for dry eye are available today and this is mainly the result of poor repeatability and inaccuracy.
This current study aims to evaluate 2 new non-invasive imaging techniques suitable for dry eye assessment.
Anterior segment optical coherence tomography (AS-OCT) is an imaging device that has the ability to image the tear meniscus of the eye in a safe and non-invasive manner. Image analysis can then indirectly determine the tear film volume. Improvements in the image resolution of these devices require a study that compares the repeatability and agreement of an older (Visante AS-OCT) and a newer instrument (Cirrus AS-OCT) which the current study aims to address.
Another method of evaluating dry eye disease is a novel technique that uses functional infrared thermography to measure tear evaporation rate. This study will also establish repeatability of measurements of the ocular surface temperature which are used to calculate tear evaporation rates.
Should these methods are found to be repeatable, they can be used in future clinical trials as an additional tool to investigate dry eye treatments.
|Study Design:||Allocation: Non-Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Screening
|Official Title:||Repeatability and Agreement of Visante and Cirrus Anterior Segment Optical Coherence Tomography and Functional Infrared Thermography|
- equipment repeatability [ Time Frame: 1 day ] [ Designated as safety issue: No ]
Part A - The repeatabilty coefficients of tear meniscus measurements derived from Visante and Cirrus AS-OCT and the agreement between tear meniscus measurements.
Part B - Infrared thermography is expected to be repeatable in capturing OST measurements which will consequently result in repeatable tear evaporation rates. Temperature changes of the ocular surface will be adequately captured.
- temperature changes [ Time Frame: 1 day ] [ Designated as safety issue: No ]Determine whether thermogram images can capture changes in temperature/the rate of tear evaporation which were introduced by warm eye mask wear.
|Study Start Date:||June 2011|
|Study Completion Date:||December 2012|
|Primary Completion Date:||December 2012 (Final data collection date for primary outcome measure)|
No Intervention: Visante AS-OCT and Cirrus AS-OCT
The tear meniscus is the thin concave strip of the tear film near the eyelid margins. During the acquisition the participants place their chins on a chin rest and look at a fixation light/target. This whole procedure should not take more than 5 minutes. The patients are allowed to blink freely except for during the acquisition time of less than 5 seconds. The procedure will be repeated for the upper and lower tear meniscus of both eyes.
Experimental: Thermography measurement
In total, four pairs of thermographic sequences on the ocluar surface temperature from volunteers will be taken.
The eye mask with a temperature of not more than 40 deg C (confirmed by thermometer) will be worn by the volunteer for 5 minutes.
Other Name: EyeGiene (Eyedetec Medical Inc., US)
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|Singapore Eye Research Institute|
|Singapore, Singapore, 168751|
|Principal Investigator:||Louis Tong, PhD||Singapore National Eye Centre|