Abstract: Sensor for imaging tear film and lipid layer

Simultaneous examination of tear film break-up and the lipid layer of the human eye: A novel sensor design (Part 1).
Z Med Phys. 2010 Sep 28. [Epub ahead of print]
Arnold S, Walter A, Eppig T, Bruenner H, Langenbucher A.
Medical Optics at the Institute of Medical Physics, University of Erlangen-Nuremberg, Erlangen, Germany; Erlangen Graduate School in Advanced Optical Technologies (SAOT), University of Erlangen-Nuremberg, Erlangen, Germany.

This article presents a non-invasive sensor setup for objective analysis of the pre-corneal human tear-film involving a time-resolved videokeratoscopy and simultaneous imaging of the lipid layer of the tear-film by a second CMOS-camera. This paper describes in detail the mechanical and optical design of the sensor setup, the realization of the entire illumination component with an integrated Placido grid projection, and the calculation of the image formation using the Placido grid. This concept is demonstrated here with a test subject in the full inter-blink period. All images were taken under physiological conditions. The sensor can assist the ophthalmologist in diagnosing Dry-Eye Syndrome. Results and other potential applications are discussed.