The Clinical Branch, NEI uses images produced by the Scheimpflug principle to quantitate eye opacities. The general goal is to find ways to accurately determine changes in a cataract lens. CB employs a Zeiss Scheimpflug Slitlamp Camera (SLC) to visualize pathological changes in anterior ocular measurements and to make geometric measurements of boundary surfaces and their distances. The SLC measuring system consists of a special photo slip lamp with a computer-based image display and analysis system. It is being used clinically primarily to measure cataract area and opacity. In past years, CSL responded to a need in the CB/NEI by replacing and enhancing the data system for the Zeiss SLC. The camera and an image acquisition and processing system were delivered to the National Eye Institute in 1986; our support for this original system component which showed some degraded system performance was the analog video recorder used for storage and recall of images. This year, CSL helped NEI develop a Macintosh II computer-based system for image acquisition and processing and is using an optical disk for image storage and retrieval. The original instrument utilized an elaborate feedback system for control of light intensity and synchronization, which was retained. The existing Bosch Newvicon Video Camera was connected to Data Translation's Macintosh II compatible, Quick Capture Image Acquisition System. Quick Capture includes an 8-bit video ADC operating at 25 frames/second, and writes data to a 768 x 512 vertical image buffer.
