| 摘要 |
An analysis of the corneal shape through the combination of several keratometer measurements is disclosed. The eye is preferably scanned to a nasal angular position, a central angular position and a temporal angular position. The central position is straight ahead along the patient's line of sight. The temporal and nasal positions are in the broad range of up to 5 DEG to 22 DEG ; the intermediate range of 10 to 15 DEG ; and the narrow range of 12 DEG to 14 DEG on either side. Measurements in sphere, cylinder and axes are taken. Astigmatism is in the more preferable format of 0 DEG -90 DEG astigmatism and 45 DEG -135 DEG astigmatism. When each individual point is measured with its respective estimate for sphere and cylinder components, these measurements are fitted to an idealized parameter. Then the three sets of curvature measurements taken at the specified locations are reduced to a set of adjusted, idealized curvatures all fitted to an elliptical model. Thereafter, these fitted values create final corneal shaped parameters, the particular process here including the creation of intermediate parameters. Finally, readings of central "k", corneal shape, apex position, cap size, vault height, corrected central "k" and goodness of fit are all set forth.
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