The cornea is the clear fibrous tissue forming the front surface of the eye. Its shape is very important in determining visual acuity. The shape is also important for fitting contact lenses and performing corneal refractive surgery.
To recover the shape of the cornea, clinicians use one of several commercially available corneal topography instruments known as videokeratographs. These devices project a pattern onto the cornea and record the reflected image. The image is then analyzed to recover the shape information.
We have developed a new analysis algorithm that has several advantages compared to current approaches: it is more accurate, it directly recovers position of the cornea, and it produces a continuous map over the entire surface. To develop this algorithm, we have assimilated ideas from a variety of fields, including ray-tracing (computer graphics and optics), smooth B-spline surfaces (geometric modeling) and simulation.
This algorithm for accurately measuring the cornea is an essential first step in the scientific visualization of corneal topography. After measuring the shape of the cornea, it is important to be able to display the results in a manner that highlights the important features of the surface and is understandable to viewers with a wide variety of back-grounds. We have developed new scientific visualization approaches which overcome some of the shortcomings of the displays used in current corneal topography instruments.
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