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Method for measuring diopter and drawing corneal topography diagram based on Placido plate

A technology of diopter and data points, applied in the field of optometry, can solve the problems of discontinuity of corneal topography and fluctuation of diopter, and achieve the effect of avoiding discontinuity and good effect.

Inactive Publication Date: 2013-03-13
ZHEJIANG UNIV OF TECH
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Problems solved by technology

[0007] The present invention provides a method for measuring diopter and drawing corneal topography based on the Placido disc, which continuously and truly reflects the refractive index of the front surface of the cornea, and solves the problem of large diopter fluctuations and discontinuous corneal topography in the prior art question

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  • Method for measuring diopter and drawing corneal topography diagram based on Placido plate
  • Method for measuring diopter and drawing corneal topography diagram based on Placido plate
  • Method for measuring diopter and drawing corneal topography diagram based on Placido plate

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Embodiment 1

[0035] (1) The diopter data on each ring is calculated according to the Placido disc, and 256 data are calculated on each of the 24 rings of the Placido disc. Calculation method References (KlyceSD. Computer-assisted corneal topography. High-resolution graphic presentation and analysis of keratoscopy [J]. Investigative Ophthalmology and Visual Science, 1984, 25(12): 1426-1435.) published method.

[0036] (2) For all data points x on each ring k (k=1~256 integer, which is the serial number of the data point on the current ring) smoothing process respectively to get the smoothed data point The smoothing process is:

[0037] Set the smoothing factor n, when the smoothing factor n is an odd number, the data point is shown in formula (1):

[0038] x k * = 1 n ( x k - n...

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Abstract

The invention provides a method for measuring diopter and drawing a corneal topography diagram based on a Placido plate. The method comprises the steps of: (1) calculating data of the diopter of every ring based on the Placido plate; (2) respectively smoothing all data points xk of every ring to obtain smoothed data points; and (3) performing reverse distance interpolation on all the smoothed data points to obtain the diopter. Finally, the corneal topography diagram is drawn according to the diopter. The refraction index of a corneal front surface can be continuously and truly reflected, and the problems of large diopter fluctuations and non-continuous corneal topography diagram of the prior art can be solved.

Description

technical field [0001] The invention relates to the field of optometry, in particular to a method for measuring diopter and drawing corneal topography based on a Placido disc. Background technique [0002] The term corneal topography borrows concepts from topographic surveys to reflect the morphology of the corneal surface. Corneal topography is to record and analyze the surface of the cornea as a local topography by using different methods. It uses a computer image processing system to digitally analyze the corneal morphology, and the obtained information is displayed in color maps with different characteristics. It is called corneal topography because it looks like the ups and downs of the topographical surface in geography. [0003] Corneal topography is a pseudo-color map of a certain feature of the cornea, usually expressed in the form of contour lines. Corneal topography represents the distribution of corneal properties with changes in color, and realizes the functio...

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Application Information

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IPC IPC(8): A61B3/103A61B3/107
Inventor 周明华隋成华徐丹阳童建平唐轶峻高建勋
Owner ZHEJIANG UNIV OF TECH
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