Intraocular Lens Power Selection Using a Super Formula
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Solution Overview
Problem
Existing intraocular lens (IOL) calculation formulas diverge significantly at specified ranges of input parameters, leading to inaccuracies and a lack of consensus among ophthalmologists on which formula to use, despite individual formulas working better with certain input parameters.
Innovation Solution
A combined 'super' formula is developed by graphically integrating the most accurate portions of multiple IOL calculation formulas, using a three-dimensional super surface and machine learning to adjust lens selection parameters based on estimated errors, thereby enhancing accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple individual IOL calculation formulas are used, then each formula works best with certain input parameters, but the formulas diverge significantly at specified ranges leading to inaccuracies
Solution Approach 1:
The patent combines multiple individual IOL calculation formulas into a single unified 'super' formula that integrates the strengths of each individual formula. This super formula uses a weighted combination approach where different formulas contribute to the final calculation based on their proven accuracy in specific parameter ranges, thereby resolving the divergence issue while maintaining adaptability across all ocular measurement ranges.
Solution Approach 2:
The patent applies local quality by allowing different portions of the super formula to have different weights based on the input parameter ranges. Specifically, the formula adjusts the contribution of individual IOL formulas (SRK I, SRK/T, Hoffer Q, Holladay I, Haigis) depending on the axial length and corneal power values, ensuring that each formula's strength is utilized in its optimal range while maintaining overall consistency.
2Ease of operation
If a single formula is selected to determine lens power, then the calculation process is simplified, but accuracy is reduced due to formula divergence
Solution Approach 1:
The patent merges multiple formulas into a single operational super formula that maintains simplicity of use while improving accuracy. The unified formula structure allows it to be applied universally across all cases without requiring the surgeon to select between multiple formulas, yet internally it leverages the strengths of each individual formula through its weighted combination mechanism.
Solution Approach 2:
The super formula achieves universality by being applicable to all ocular measurement ranges and parameter combinations. It functions as a multi-functional calculation tool that adapts its internal weighting based on the input parameters, eliminating the need for formula selection while maintaining high accuracy across diverse clinical scenarios.
3Measurement precision
If formula adjustments are applied to improve results for specific parameter ranges, then accuracy improves for those ranges, but the overall system complexity increases
Solution Approach 1:
The patent changes the parameters of the calculation system by introducing a weighted combination framework where the weights of individual formulas are adjusted based on input parameter ranges. This approach maintains a unified formula structure while dynamically adapting the contribution of each underlying formula, thereby improving accuracy without significantly increasing operational complexity.
Solution Approach 2:
The super formula incorporates dynamic weighting that automatically adjusts based on the input axial length and corneal power values. This dynamic adaptation allows the formula to optimize its composition for each specific case without requiring manual intervention or complex decision-making processes, balancing accuracy improvement with system simplicity.
Data Source
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AI summary
The disclosure provides for an apparatus for intraocular lens selection. The apparatus may include a biometer and an autorefractor. The biometer may be configured to obtain at least two ocular measurement parameters for an eye. The autorefractor may be configured to obtain a post-operative refraction of the eye. The apparatus may also include a user interface configured to obtain a lens selection parameter for the eye, a memory, and a processor communicatively coupled to the biometer, the user interface, the autorefractor, and the memory. The processor may be configured to determine an intraocular lens power based on a formula using the at least two ocular measurement parameters. The processor may be configured to correlate the at least two ocular measurement parameters, the intraocular lens power, and the post-operative refraction as a training set.