Lacrimal equilibration time (LET): a quick and simple dry eye test

We investigated the benefits of a new test on the lacrimal system for Dry Eye. This additional test to facilitate the diagnosis of dry eye is described and compared with the Schirmer test and with the results of a patient questionnaire. This simple test uses materials available in all optometric practices. An assistant with brief training can administer the test for the optometrist. The patient's monocular distance visual acuity was measured. One drop of Celluvisc was instilled into each eye; a stop watch recorded the time necessary for the patient to regain the predropped visual acuity. Each patient received a standard Schirmer test and answered a questionnaire. Preliminary results from this new test suggest a correlation between a dry eye with patient symptoms and the length of time for return to normal visual acuity after the use of one drop of Celluvisc. Further investigations should be conducted with a larger population using a precise eye drop dispenser. With this new test, a practitioner would have another method to diagnose a dry eye.