Patent Document ID: 7866820
Application ID: 11830372
Patent Status: 1

Claim One:
1. A method for making an ophthalmic topography measurement of a target surface including the cornea, the limbus and at least a portion of the adjacent scleral region, comprising: conditioning at least a portion of the target surface such that it diffusely reflects an image projected thereon; projecting a selected image onto a substantial portion of the target surface; obtaining an image of the diffusely reflected image; extracting selected features of the image; and using the extracted features to determine a corneo-scleral surface topography, wherein the step of extracting selected features of the image comprises finding the center of the image, referred to as a starting node; extracting a plurality of horizontal line features from the image to form a horizontal line array; extracting a plurality of vertical line features from the image to form a vertical line array; finding an intersection point in the horizontal and vertical line arrays; finding a plurality of neighboring intersection points in the horizontal and vertical line arrays, wherein each intersection point is a node; continuing finding a plurality of neighboring intersection points in the horizontal and vertical line arrays until a satisfactory number of intersection points (nodes) have been found to determine the topography of the corneo-scleral surface, further comprising determining a region of interest (ROI) in the center of the image; computing a sum of all pixels in a row, saving the sum as computed for all rows, and saving the sum in a row sum array; computing a sum of all pixels in a column, saving the sum as computed for all columns, and saving the sum in a column sum array; determining a peak value in the row sum array corresponding to a Y coordinate of a center of a reticle image; and determining a peak value in the column sum array corresponding to a X coordinate of a center of a reticle image on the image.