Intraocular Lens Position Estimation Using Wavefront Aberrometry
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for determining the post-surgical effective lens position (ELP) of an intraocular lens (IOL) in cataract surgery are inaccurate, especially for patients who have undergone refractive surgery, due to reliance on keratometric measurements and biometry data, which can introduce errors and are not clinically valid for altered corneal surfaces.
Innovation Solution
The method involves measuring aphakic ocular power directly using a wavefront aberrometer during surgery, eliminating the need for total corneal power and axial length measurements, and using this measurement to estimate the ELP and determine the appropriate optical power for the IOL, thereby reducing measurement errors and the complexity of preoperative diagnostics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If keratometric measurements and biometry data are used to determine ELP, then the method is applicable to general patients, but measurement errors increase and accuracy decreases for patients who have undergone refractive surgery
Solution Approach 1:
The patent applies local quality by using different measurement approaches for different patient categories. For patients who have undergone refractive surgery, the invention uses wavefront aberrometry to measure ocular power directly, bypassing the keratometric measurements that are invalid for these patients. This localized adaptation to patient history resolves the contradiction between general applicability and measurement accuracy.
Solution Approach 2:
The invention changes the measurement parameters from keratometric readings (which measure only corneal curvature) to direct ocular power measurements using wavefront aberrometry. This parameter change allows accurate ELP determination for refractive surgery patients by measuring the actual optical power of the eye rather than relying on corneal curvature assumptions that are invalidated by prior refractive procedures.
2Loss of information
If multiple preoperative measurements (keratometry, biometry) are performed, then comprehensive data is obtained, but measurement complexity and potential for error increase
Solution Approach 1:
The patent merges multiple measurement functions into a single wavefront aberrometer device. This single instrument performs what previously required separate keratometric measurements, biometry, and refractive error assessments, thereby reducing device complexity while maintaining comprehensive ocular data collection. The wavefront aberrometer integrates multiple measurement capabilities into one system.
Solution Approach 2:
The wavefront aberrometer is presented as a universal measurement device that can obtain all necessary ocular parameters (ocular power, axial length, corneal curvature) through a single measurement process. This multi-functional approach eliminates the need for multiple specialized devices and reduces the overall complexity of the measurement system while preserving data completeness.
3Ease of operation
If traditional ELP estimation methods are used, then the process is simple, but residual refractive errors increase after surgery
Solution Approach 1:
The patent replaces traditional mechanical/optical keratometric measurement systems with wavefront aberrometry, which uses optical wavefront analysis to directly measure ocular power. This substitution maintains operational simplicity while dramatically improving the precision of ELP estimation and subsequent IOL power selection, particularly for refractive surgery patients.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An ophthalmic method for determining a relationship between aphakic ocular power and estimated effective lens position (ELP) of an intraocular lens (IOL) to be implanted in a patient's eye. The method can be used to determine an estimate of the ELP of an IOL given the aphakic ocular power of the patient's eye, for example, without measurement of the corneal curvature or axial length of the patient's eye. The estimate of ELP can then be used to determine a suitable value of optical power for the IOL to be implanted in the patient's eye.