Combined Wavefront and Topography Laser Vision Correction
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Solution Overview
Problem
Current wavefront guided laser refraction techniques fail to accurately account for transverse ray movement, obliquity of the refracting surface, and local variations in the anterior corneal surface shape during laser vision correction, leading to inefficiencies and inaccuracies in achieving the desired refractive state.
Innovation Solution
The integration of wavefront and corneal topographical data to determine a customized ablation target for laser vision correction, using full ray tracing to account for oblique surface effects and transverse wavefront propagation, ensuring the desired refractive effect is achieved by precisely calculating the amount of tissue to be removed at each corneal location.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If wavefront error is converted to wavefront error in corneal tissue without accounting for transverse ray movement and obliquity, then the ablation target can be determined using simple conversion, but the accuracy of the ablation target is insufficient
Solution Approach 1:
The patent combines wavefront eye refractor data with corneal topography information into a unified ablation target determination system. By merging these two measurement systems and integrating their data through ray tracing algorithms, the invention achieves higher ablation accuracy than either system could provide independently, while managing the complexity through systematic data integration.
Solution Approach 2:
The patent introduces full ray tracing as an intermediary computational process that bridges the gap between wavefront error measurements and corneal tissue ablation targets. This intermediary step accounts for transverse ray movement and obliquity effects, transforming raw wavefront data into accurate ablation prescriptions by modeling light propagation through the ocular media.
2Manufacturing precision
If traditional wavefront conversion methods are used, then the processing is simpler and faster, but the ablation target does not adequately account for transverse ray movement, obliquity, and local corneal surface variations
Solution Approach 1:
The patent performs preliminary ray tracing calculations during the treatment planning phase to pre-determine the exact ablation target that accounts for transverse ray movement and obliquity. By performing these complex calculations beforehand rather than during real-time treatment, the system achieves high ablation precision while minimizing loss of time during the actual surgical procedure.
3Reliability
If wavefront guided laser refraction is performed without accounting for local variations in anterior corneal surface shape, then the treatment can be applied uniformly, but the desired refractive state cannot be accurately achieved
Solution Approach 1:
The patent applies local quality by using corneal topography to capture local variations in the anterior corneal surface shape and incorporating these location-specific characteristics into the ablation target. Instead of applying a uniform treatment based solely on average wavefront error, the system tailors the ablation prescription to account for local corneal geometry at each treatment zone, thereby improving refractive correction reliability.
Data Source
AI summary
Methods, software, and systems are provided for determining an ablation target shape for a treatment for an eye of a patient. Techniques include determining wavefront information from the eye of the patient with a wavefront eye refractometer, determining anterior corneal shape information from the eye with a corneal topography device, and combining the wavefront information and the anterior corneal shape information to determine the ablation target shape.