Improving the visualization of drusen in age-related macular degeneration through maximum entropy digitization and stereo viewing

摘要

The purpose of this paper is to report on the effects of stereopsis, resolution, color, and contrast on detecting and evaluating lesions associated with age-related macular degeneration (ARMD) in retinal images. Ten stereo-pairs were scanned from 35-mm color photographs at two different spatial resolutions (33 pixels/mm and 100 pixels/mm). The effects of image quality were established by presenting the digital images to trained analysts with varying degrees of spatial resolution and contrast viewed in 2-D and stereo. Stereopsis was produced using shuttered goggles to view the stereo pair on the computer monitor. Resolution had less of an effect on feature detection than contrast for the ARMD lesions studied. Detection was reduced only 12% for a 4X reduction in spatial resolution. Detection of ARMD lesions was reduced by more than 50% when contrast was reduced by a factor of 4. There was a 10 - 20% increase in the ability to detect drusen using full color images compared to red-free. The stereo effect produced by the shutter glasses and computer monitor was similar to that observed in viewing stereo slides. With high digital image quality, the stereo viewing computer-based system demonstrated significant potential for grading and analysis of retinal images for ARMD.