Non-invasive Tear Film Dynamic Measurements in Normal, MGD and ADDE Subjects After Saline Instillation

The team will use a one page questionnaire to obtain subjective input before the first set of measurements and after instilling the Saline drop.

The wavefront instrument measures the eye's ability to create a sharp image by briefly shining a laser light from the wavefront sensor into the eye and measuring the light that bounces back through the cornea. For these measurements, subjects will sit on a chair and be instructed to place their chin in a chin rest and lean their forehead against a forehead rest. The subject will be instructed to hold his/her head steady, look in a certain direction, blink or not blink. We will obtain the measurements over a short period of up to approximately 45 seconds. We will start recording data asking the subject to either blink naturally or to hold his/her eye open for a few (up to 10) seconds, and repeat the blink and hold sequence usually for up to four times.

One drop will be instilled in both eyes and patient will wait 5 minutes prior to repeating the questionnaire and wavefront sensor. A single drop is approximately 30 µL and will be placed into the inferior cul-de-sac while the patient looks up.