Variable-Power Accommodative Intraocular Lens Design
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Solution Overview
Problem
Conventional intraocular lenses for presbyopia lack the ability to change optical power post-implantation, leading to blurred vision at various distances and the need for additional optical aids, while existing solutions like multifocal and pseudo-accommodative lenses suffer from issues like halos, loss of sensitivity to contrast, and increased optical aberrations.
Innovation Solution
A variable power accommodative intraocular lens design that utilizes ciliary muscle contractions to change its power by varying the equatorial diameter of the optical zone, featuring a substrate with haptics that transmit external forces and a triplet structure with refracting interfaces, allowing for significant power changes without moving within the eye.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional intraocular lenses are used for presbyopia, then the lens structure is simple and easy to manufacture, but the lens cannot change optical power post-implantation leading to blurred vision at various distances
Solution Approach 1:
The patent applies the dynamics principle by creating a lens structure that transitions from static to dynamic. The intraocular lens incorporates a deformable optical zone with a flexible basement membrane that can change shape in response to ciliary muscle contractions. This allows the lens to dynamically adjust its optical power after implantation, enabling accommodation for different viewing distances without requiring multiple separate lenses or complex mechanical adjustment mechanisms.
Solution Approach 2:
The patent utilizes parameter changes by modifying the physical state of the optical zone. The flexible basement membrane allows the optical zone to change its curvature and thickness parameters in response to physiological forces from the ciliary muscle. This parameter transformation enables the lens to vary its refractive power continuously, providing adaptability for presbyopia correction while maintaining a relatively simple overall structure.
2Adaptability or versatility
If multifocal lenses are used to correct presbyopia, then vision at multiple distances is improved, but halos and loss of sensitivity to contrast occur
Solution Approach 1:
The patent employs dynamics to eliminate the harmful effects of static multifocal lenses. Instead of having fixed optical zones for different distances, the lens creates a single dynamic optical zone that can concentrate light at one focal point at a time based on ciliary muscle activity. This dynamic focusing mechanism prevents the simultaneous formation of multiple focal points that cause halos and contrast sensitivity loss, while still providing vision at multiple distances through sequential focusing.
3Adaptability or versatility
If pseudo-accommodative lenses are used, then accommodation is restored, but optical aberrations increase
Solution Approach 1:
The patent applies parameter changes by using a flexible basement membrane that allows natural, gradual adjustment of the optical zone's shape parameters. This physiological approach to parameter transformation follows the natural accommodation mechanism, avoiding the abrupt or mechanical parameter changes in pseudo-accommodative lenses that generate optical aberrations. The continuous, biologically-driven parameter adjustment maintains optical quality while restoring accommodation.
4Adaptability or versatility
If variable power accommodative intraocular lens is implanted, then clear vision at multiple distances is achieved, but the implantation requires larger incisions
Solution Approach 1:
The patent utilizes flexible shells and thin films by incorporating a flexible basement membrane in the optical zone. This thin, deformable structure allows the lens to be folded or compressed for insertion through small corneal incisions, then expand to its functional shape inside the eye. The flexible membrane enables the complex variable-power structure to be delivered minimally invasively while maintaining its ability to provide clear vision at multiple distances through physiological deformation.
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
Enables clear vision at multiple distances with minimal corneal incisions, maintaining optical quality and allowing for implantation through small incisions, effectively addressing the limitations of current intraocular lens designs.
Implementation Method 1
The invention refers to an intraocular lens that provides a variable optical power controlled by the contraction of the ciliary muscle
Implementation Method 2
The optical zone comprises four refracting interfaces, with a single common optical axis that separate three materials
Data Source
Figure 1~2B
Figure 3~4C
Figure 5~6B
AI summary
The new variable power accommodative intraocular lens is comprised by a central body or optical zone that has at least four dioptres that separate a minimum of three means. These are connected by means of a substrate that holds them in an equatorial manner, and which includes the bases of the fasteners of the lens embedded in its core. The lens changes its power in response to variations in the equatorial diameter of the means that comprise the optical zone. Thanks to its design, the lens achieves variations in the optical powers greater than one dioptre per micrometre of equatorial compression. This is achieved through the real change of the curvature radii of the dioptres that comprise the optical zone, as well as the central thicknesses along the length of the optical axis of the different means that limit said dioptres. Preferably the intraocular lens works in combination with a capsular ring, to which the fasteners are fixed and whose external diameter determines the power of the lens. The change of power mechanism in the lens initiates with the contraction of the ciliary muscle of the patient in response to the accommodative force.