Assessment of topographic semi-meridian parameters for corneal astigmatism analysis and vector planning treatment

摘要

Techniques are disclosed in which a topographic parameter is determined in each hemidivision of the eye by considering the topography of reflected images from a multiplicity of illuminated concentric rings of the cornea. A simulated spherocylinder is produced to fit into each ring and conform to the topography thereof from which a topographic parameter for each ring can be obtained. All of the topographic parameters of each ring are combined and a mean summated value is obtained representing magnitude and meridian of each hemidivision. From these parameters, a single topographic value for the entire eye (CorT) can be found as well as a value representing topographic disparity (TD) between the two hemidivisions. The topography values for the hemidivisions are used in a vector planning system to obtain treatment parameters in a single step operation.

主权项

1. A method of quantifying corneal topographic astigmatism (CorT) comprising,
considering at least a portion of an eye of a patient to be divided into a multiplicity of concentric rings, forming a curved surface for each ring in which the curved surface conforms to a topography of the cornea of the respective ring, determining parameters of the cornea in each ring representative of the corneal topography of the ring, and vectorially summating the corneal parameters of all of the rings and obtaining a mean summated vectorial value representing a value of corneal topographic astigmatism (CorT) for said portion of the cornea of the eye of the patient.