The long term goal is to apply new technologies to development of an instrument, the corneal scanner, that will easily measure the central and peripheral curvatures of the cornea and not be affected by distortion of the cornea. Current instruments can only measure the central 25% of the cornea and cannot be effectively used if the cornea is distorted. The need to have an instrument to measure the entire corneal curvature is valuable in examining for contact lenses, in surgeries that modify the corneal curvature (cataract extraction, corneal transplant, astigmatic procedures, radial keratotomy), in keratoconus and conditions that create an irregular corneal surface as scars, edema, abrasions and keratitis. The scanner consists of a special television camera attached to a photo-slitlamp, a digitizer and a computer. The slit of vertical light from the slitlamp is passed across the cornea and the corneal curvatures recorded by the camera are analyzed by the computer. The readout tells the steepest and flattest meridians, the amount and axis of the astigmatism if present, the curvatures of the peripheral cornea, and a contour map of the cornea. Phase I will consist of digitizing the TY images of the cornea, developing software to be able to analyze the digitized data, and specifying the parameters and components for the design of a prototype system. Specific problems to be addressed and answered are the following: (1) How critical is it to have the central and peripheral cornea simultaneously in fine focus? (2) Is the reflected corneal light of sufficient intensity for the TV camera? (3) How is accuracy affected by the angle of the slitlight and camera and distance of the latter from the cornea? (4) How will the cornea scanning be done? (5) How can eye motion be detected and how much motion is permissible? Phase II will consist of constructing and clinically testing the prototype system. The corneal scanner will be used by ophthalmologists, optometrists, and opticians.
