Evaluating the Clinical Utility of Noninvasive Methods for Measuring Tear Film Surface Quality

The cornea is covered by a thin tear film that performs various vital functions including the provision of a high quality optical surface and protecting the cornea. Clinical methods for assessing tear film surface quality are mostly invasive and often unreliable. Recently, several non-invasive methods have been proposed. In this letter, we review three promising optical techniques based on high speed videokeratoscopy, wavefront sensing and lateral shearing interferometry, and evaluate their clinical utility.