A New Computed Imaging System for Measurement of Eyelid Saccades

Abstract

Abstract: : Purpose: Eye saccades are accompanied by vertical eyelid movements that are called eyelid saccades. These lid movements are usually recorded in laboratories with magnetic search coil techniques. In clinical settings they are evaluated only in a qualitative manner. The purpose of the present study was to develop a simple and feasible method to measure eyelid saccades in clinic. Methods: Eyelid saccades were recorded using a commercial digital video camera connected to a microcomputer by a frame-grabber PC device. A specific software was written in Delphi 5.0 to calculate the spatial location, on the vertical meridian, of short wavelength pixels in the blue range. A small blue eye make-up was then used to highlight the eyelid margin. Results: With this methodology eyelid saccades could easily be measured with a temporal resolution of 33.33 ms due to limitation of the NTSC video system. The graph shows a typical example of 10 and 20 degrees downward lid saccades in the lower hemi-field. Conclusion: Eyelid saccades can be measured using a commercial video camera and a PC with a frame grabber device.  

Keywords: 410 eyelid • 430 imaging/image analysis: clinical • 429 image processing