| 摘要 |
A technique for evaluating the topography of a cornea (140) is disclosed, which utilizes a virtual image of a keratoscope pattern. The disclosed topography system includes a structured light source (110) to create the keratoscope pattern (5) or another diagnostic pattern, an optical assembly (130) to focus the created pattern upon or behind the cornea (140), and for capturing the image reflected off the patient's eye and directing the reflected image toward in imaging system (150, 195) for processing. Light emitted by the light source (110) is preferably not in the visible range to minimize discomfort to the patient. Since the topography is evaluated with a projected virtual image, there is no nose or brow shadow, thereby allowing better corneal coverage. The optical system includes an aperture stop (190) which is approximating the center of a normal cornea (140). Thus, wide angle capture is achieved as reflected rays reaching the imaging system (150, 195) appear as if they originated at the center of the cornea (140). A pupil detection mechanism is disclosed which is performed independently of the diagnostic pattern illumination, thereby facilitating pupil detection. In an alternative embodiment, the diagnostic pattern is generated using a variable light pattern generator, which provides diagnostic abilities. The disclosed topography system may be reconfigured to serve as a visual field measuring device, or a perimeter.
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