Toric IOL with Central Aperture Mask for Astigmatism Tolerance
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Solution Overview
Problem
Current intraocular lenses (IOLs) do not effectively correct astigmatism and are sensitive to rotational misplacement, leading to sub-optimal vision correction and the need for inconvenient post-operative strategies.
Innovation Solution
An intraocular lens with a refractive element having different powers in different meridians, combined with a mask that blocks light in an annular region and allows light to pass through a central aperture, enhancing astigmatism correction and increasing tolerance to rotational misplacement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional intraocular lens is used to correct astigmatism, then the lens can provide basic refractive correction, but the lens is highly sensitive to rotational misplacement resulting in sub-optimal vision correction
Solution Approach 1:
The lens is divided into distinct functional zones: a central optical zone with specific refractive power for astigmatism correction, and a peripheral annular region with different optical properties. This segmentation allows the central zone to maintain precise astigmatism correction while the peripheral zone provides rotational tolerance by allowing light passage that is less sensitive to orientation.
Solution Approach 2:
Different regions of the lens are assigned different optical qualities: the central zone has optimized refractive power and cylindrical correction for precise astigmatism management, while the peripheral annular region has reduced power or different material properties that provide rotational tolerance. This local differentiation resolves the contradiction between precision and rotational sensitivity.
2Illumination intensity
If the intraocular lens uses a large aperture to maximize light transmission, then brightness is improved, but rotational misplacement has a greater negative impact on vision quality
Solution Approach 1:
The aperture is segmented into a central transmission zone and a peripheral annular zone. The central zone maintains full aperture for optimal light transmission and brightness, while the peripheral annular region has modified optical properties that reduce the impact of rotational misplacement on overall vision quality.
Solution Approach 2:
The lens exhibits local quality variations where the central region provides high light transmission for brightness, while the peripheral region has reduced power or different refractive properties that provide rotational tolerance. This allows the system to maintain both brightness and rotational insensitivity simultaneously.
3Measurement precision
If the intraocular lens is designed with high astigmatism correction power, then astigmatism correction is improved, but the lens becomes more sensitive to rotational misplacement
Solution Approach 1:
The lens separates the high-power astigmatism correction function into the central optical zone, while the peripheral annular region provides rotational tolerance with reduced power. This segmentation allows the central zone to deliver precise astigmatism correction without the peripheral zones contributing to rotational sensitivity.
Solution Approach 2:
The lens applies local quality differentiation where the central zone has high cylindrical power for precise astigmatism correction, while the peripheral region has reduced power or different material properties that provide adaptability to rotational misplacement. This resolves the contradiction between correction precision and rotational tolerance.
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
The solution effectively corrects astigmatism and increases the depth of focus, allowing for up to 15 degrees of rotational misplacement tolerance, significantly improving vision acuity and reducing the risk of sub-optimal outcomes from IOL placement.
Implementation Method 1
The refractive element has a first power in a first meridian and a second power greater than the first power in a second meridian. A magnitude of the first and second powers and a location of the first and second meridians are configured to correct astigmatism in a human eye.
Implementation Method 2
The mask is configured to block a substantial portion of light from passing through an annular region thereof and to permit a substantial portion of light to pass through a central aperture thereof to enhance an astigmatism correction rotational misplacement range.
Implementation Method 3
The mask is configured to permit a substantial portion of light to pass through a central aperture thereof to enhance an astigmatism correction rotational misplacement range and to increase depth of focus.
Data Source
AI summary
An intraocular lens is provided that includes a refractive element and a mask. The refractive element has a first power in a first meridian and a second power greater than the first power in a second meridian. A magnitude of the first and second powers and a location of the first and second meridians are configured to correct astigmatism in a human eye. The mask is configured to block a substantial portion of light from passing through an annular region thereof and to permit a substantial portion of light to pass through a central aperture thereof to enhance an astigmatism correction rotational misplacement range and depth of focus.