Intraocular Lens Attenuation Zone for Negative Dysphotopsia
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing intraocular lenses (IOLs) fail to address negative dysphotopsia (ND) and posterior capsule opacification (PCO), with ND caused by light missing the IOL at higher angles and PCO resulting from lens fiber migration, despite advancements in IOL design.
Innovation Solution
Intraocular lenses with an attenuation optical zone that gradually reduces optical power to zero at the edge, featuring a smooth transition and a sharper edge design to minimize ray deviation and increase vault height, reducing ND and PCO.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a conventional IOL design with full optical power across the optic is used, then central vision is optimized, but negative dysphotopsia occurs due to light missing the IOL at higher angles
Solution Approach 1:
The IOL optic is divided into zones with different optical properties: a central optical zone with full optical power for central vision, and a peripheral attenuation optical zone with gradually reduced power. This local differentiation allows the central zone to optimize central vision while the peripheral zone reduces ray deviation at higher angles, preventing negative dysphotopsia.
Solution Approach 2:
The optical power parameter is varied across the optic diameter. The attenuation optical zone features a gradual reduction in optical power from the central zone toward the periphery, with the rate of reduction optimized to minimize angular deviation of marginal rays. This parameter change ensures that light at higher angles is less deviated, reducing the angular interval on the retina that would otherwise be unilluminated.
2Object-affected harmful factors
If the IOL optic diameter is increased to reduce negative dysphotopsia, then more light is captured at higher angles, but the lens becomes larger and may increase manufacturing complexity
Solution Approach 1:
Rather than uniformly increasing the entire IOL optic diameter, the invention applies optical attenuation specifically in the peripheral zone. This localized approach addresses negative dysphotopsia without requiring a proportional increase in the entire lens size, thereby limiting the increase in manufacturing complexity to only the peripheral attenuation zone rather than the entire device.
3Object-affected harmful factors
If a sharp edge design is used to minimize ray deviation, then negative dysphotopsia is reduced, but the edge may cause stress concentration and reduce structural integrity
Solution Approach 1:
The optical power parameter is gradually reduced to zero at the periphery of the attenuation optical zone, creating a smooth optical transition rather than an abrupt edge. This gradual parameter change minimizes ray deviation and negative dysphotopsia while avoiding sharp geometric edges that would cause stress concentration, thereby maintaining structural integrity.
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 design effectively minimizes ND by ensuring minimal light deviation at the edge and reduces PCO by increasing pressure at the capsular bend, enhancing visual quality and reducing the need for secondary interventions.
Implementation Method 1
the light passing the IOL at the lower angles of incidence is refracted, changing its direction to a lower angle
Implementation Method 2
increasing pressure at the capsular bend, which lowers risk of PCO
Data Source
AI summary
Intraocular lenses for reducing negative dysphotpsia (ND) are described herein. An example ophthalmic lens can include an optic (200) with a central optical zone (225) disposed about the optical axis (OA) and an attenuation optical zone (220) disposed about the central optical zone (225), wherein the attenuation optical zone (220) is contiguous with the central optical zone (225), and wherein optical power of the ophthalmic lens is gradually reduced within the attenuation optical zone (220).