Corneal topography using computer analyzed rasterstereographic images

This paper describes a new method for determining corneal surface detail utilizing a modified Zeiss photo slit lamp. This system projects a grid onto the cornea through a cobalt blue filter. The tear film is stained with fluorescein, causing the projected grid pattern to be visible on the corneal surface. A video image of the grid is then digitized by an image processor which calculates surface detail by evaluating the distortion of the grid lines. Information on curvature and surface detail is obtained across the full corneal surface, both the central optical axis and peripherally beyond the limbus.