Adjustable Intraocular Lens Using UV-Induced Refractive Index Changes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for adjusting the optical power of intraocular lenses after implantation are limited by slow diffusion processes, low spatial resolution, and uncontrollable thickness changes, primarily due to the reliance on free monomers and diffusion mechanisms.
Innovation Solution
Intraocular lenses with a single polymer matrix containing crosslinkable pendant groups that increase in volume upon crosslinking, and photobleachable chromophores that change refractive index upon radiation exposure, allowing for precise adjustment of optical power without free monomers and secondary UV exposure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If free monomers are used in the lens matrix to enable optical power adjustment through UV irradiation, then the lens can be adjusted post-implantation, but the adjustment process becomes slow due to monomer diffusion and spatial resolution is limited
Solution Approach 1:
The patent removes free monomers from the lens matrix, extracting the problematic diffusing component while retaining the crosslinkable polymer structure. This eliminates the slow diffusion process that limited adjustment speed, allowing direct UV-induced crosslinking without monomer migration delays.
Solution Approach 2:
The patent changes the chemical state of the adjustable component from free monomers to crosslinkable pendant groups on polymer chains. This parameter change transforms the adjustment mechanism from diffusion-limited to direct photochemical reaction, significantly increasing adjustment speed while maintaining spatial resolution.
2Adaptability or versatility
If free monomers diffuse into irradiated regions to cause swelling and increase optical power, then lens power can be adjusted, but spatial resolution of the adjustment is limited
Solution Approach 1:
The patent extracts free monomers from the system, eliminating the diffusion process that blurred spatial boundaries. Without free monomer diffusion, the UV-irradiated regions maintain sharp boundaries, preserving high spatial resolution in the optical power adjustment pattern.
Solution Approach 2:
The patent replaces the mechanical diffusion process with a direct photochemical crosslinking mechanism. Instead of relying on monomer migration through the matrix, the adjustment occurs through localized UV-induced crosslinking of pendant groups, providing precise spatial control without diffusion-related blurring.
3Adaptability or versatility
If monomers diffuse from adjacent regions into irradiated regions, then optical power increases in the irradiated area, but thickness decreases in adjacent regions causing uncontrollable shape changes
Solution Approach 1:
The patent removes free monomers from the lens matrix, eliminating the source of mass transfer between regions. Without free monomer diffusion, adjacent regions do not experience thickness reduction, and the irradiated regions gain optical power through crosslinking without being compensated by material migration from neighbors.
Solution Approach 2:
The patent enables localized crosslinking of pendant groups in UV-irradiated regions without affecting adjacent areas. This local quality change increases refractive index in specific zones through crosslinking density variations, while maintaining uniform thickness across the lens by preventing monomer migration from adjacent regions.
4Stability of the object's composition
If a second UV exposure is used to freeze refractive index changes, then lens power stability is improved, but device complexity and processing time increase
Solution Approach 1:
The patent removes free monomers that required a second UV exposure to stabilize the lens. Without diffusing monomers, the crosslinking reaction completes during the first UV exposure, eliminating the need for a second stabilization exposure and simplifying the processing protocol.
Solution Approach 2:
The patent incorporates crosslinkable pendant groups that are pre-positioned on polymer chains before lens fabrication. These groups undergo crosslinking during the initial UV exposure, performing the stabilization action in advance and eliminating the need for a separate second UV exposure step.
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 real-time monitoring and control of lens power changes with high spatial resolution and stability, preventing unwanted thickness changes and maintaining performance over the lens's lifetime.
Implementation Method 1
a single polymer matrix having crosslinkable pendant groups, wherein the polymer matrix increases in volume when crosslinked
Implementation Method 2
The monomers in the region exposed to the UV radiation undergo polymerization, forming polymers P
Implementation Method 3
photobleachable chromophores that change refractive index upon radiation exposure
Implementation Method 4
monomers from the un-exposed regions 40, 50 then migrate into the exposed region 30, causing that region to swell
Data Source
AI summary
Methods and devices for altering the power of a lens, such as an intraocular lens, are disclosed. In one method, the lens comprises a single polymer matrix containing crosslinkable pendant groups, wherein the polymer matrix increases in volume when crosslinked. The lens does not contain free monomer. Upon exposure to ultraviolet radiation, crosslinking causes the exposed portion of the lens to increase in volume, causing an increase in the refractive index. In another method, the lens comprises a polymer matrix containing photobleachable chromophores. Upon exposure to ultraviolet radiation, photobleaching causes a decrease in refractive index in the exposed portion without any change in lens thickness. These methods avoid the need to wait for diffusion to occur to change the lens shape and avoid the need for a second exposure to radiation to lock in the changes to the lens.