Ophthalmic Wavefront Measurement for IOL-Specific Dioptric Power

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Solution Overview

Problem

Conventional methods for calculating dioptric power after cataract surgery fail to account for the specific type of intraocular lens (IOL) implanted, leading to decreased reliability of the calculation results.

Innovation Solution

An ophthalmic apparatus that measures wavefront aberration, acquires Hartmann images, and adjusts the focusing lens position based on intraocular lens information to calculate dioptric power using an arithmetic processing method tailored to the specific type of IOL, including monofocal, multifocal, and EDoF types.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a uniform method is used to calculate dioptric power regardless of IOL type, then the measurement process is simple and fast, but the reliability of the calculation result decreases

Engineering Contradiction:
Improvereliability of dioptric power calculationVSAvoidcomplexity of measurement method
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements dynamic adaptation of the measurement method based on the detected IOL type. The system automatically selects different arithmetic processing methods corresponding to monofocal, multifocal, or EDoF IOLs, allowing the measurement process to adjust its complexity and approach according to the specific IOL characteristics, thereby improving reliability without requiring manual intervention

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the arithmetic processing parameters and calculation methods based on the IOL type detected from intraocular lens information. By modifying the calculation parameters according to whether the IOL is monofocal, multifocal, or EDoF type, the system optimizes the dioptric power calculation for each IOL category, resolving the contradiction between reliability and complexity

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If the focusing lens position is adjusted based on IOL information, then the measurement accuracy for different IOL types improves, but the measurement time increases

Engineering Contradiction:
Improveaccuracy of dioptric power calculationVSAvoidmeasurement time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system performs preliminary detection of IOL information and automatic determination of the appropriate arithmetic processing method before executing the measurement. By preparing the measurement configuration in advance based on the detected IOL type, the system minimizes the actual measurement time while maintaining high accuracy for different IOL types

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses feedback from the detected IOL information to automatically adjust the focusing lens position and selection of arithmetic processing methods. This closed-loop approach ensures that the measurement parameters are optimized for the specific IOL type, improving accuracy without requiring extensive manual adjustment time

Inventive Principle:
Principle #23Feedback

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Improves the reliability of dioptric power calculation by adapting the measurement method to the type of IOL worn, enhancing the accuracy of the calculation results.

Implementation Method 1

measure wavefront aberration of an eye to be examined wearing an intraocular lens to acquire a Hartmann image

Methodology Applied
Scientific EffectWavefront aberration measurement:

Implementation Method 2

a measurement optical system including a focusing lens

Methodology Applied
Scientific EffectFocusing: Focusing

Data Source

PatentEP4595871A1Ophthalmic device, method for controlling ophthalmic device, and program
Publication Date: 2025.08.06 TOPCON CORPORATION
  • EP4595871A1 patent drawingFigure 1
  • EP4595871A1 patent drawingFigure 2
  • EP4595871A1 patent drawingFigure 3~4

AI summary

This ophthalmic device includes a measurement optical system, an acquisition unit, a control unit, and a calculation unit. The measurement optical system includes a focusing lens. The measurement optical system measures the wavefront aberration of an eye under examination in which an intraocular lens is to be placed, and acquires a Hartmann image. The acquisition unit acquires at least intraocular lens information representing the optical characteristics of the intraocular lens. The control unit moves the focusing lens to a position corresponding to the focal length of the intraocular lens, the focal length being determined on the basis of the intraocular lens information, and causes a Hartmann image to be acquired by the measurement optical system. The calculation unit calculates, on the basis of the Hartmann image, the refractive power of the eye under examination, using a computation process method corresponding to the intraocular lens information.