Femtosecond Laser Refractive Index Modification in Ocular Tissue
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Solution Overview
Problem
There is a need for improved techniques and materials for vision correction that allow in-situ modification of refractive properties of optical components such as intraocular lenses, corneal inlays, and contact lenses, as well as direct modification of ocular tissue to provide corrected vision, particularly for conditions like cataracts and refractive errors, with a focus on creating refractive structures that cover the clinically relevant optical zone of the eye.
Innovation Solution
The use of high-repetition, low-pulse energy femtosecond lasers to modify the refractive index of optical polymeric materials or ocular tissues by inducing refractive index changes through focused laser pulses, allowing for the creation of patterned refractive structures such as Bragg gratings, arbitrary wavefronts, microlens arrays, and Fresnel lenses, which can correct vision by altering the shape and refractive properties of these materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional laser methods are used to modify refractive index, then refractive structures can be formed, but the pulse energy required is high causing tissue damage
Solution Approach 1:
The patent changes the key parameters of laser irradiation from high pulse energy to high repetition rate with low pulse energy. This parameter transformation allows the formation of refractive structures while maintaining tissue integrity, as the cumulative effect of many low-energy pulses achieves the desired refractive index modification without the damaging effects of high single-pulse energy.
Solution Approach 2:
The patent employs periodic action by using high repetition rate laser pulses (e.g., 80-200 MHz) to gradually build up the refractive index modification. Instead of relying on a single high-energy pulse, the periodic application of low-energy pulses accumulates the desired effect over time, allowing precise control and avoiding tissue damage.
2Manufacturing precision
If high pulse energy lasers are used, then refractive index changes can be achieved, but manufacturing precision is reduced due to tissue damage
Solution Approach 1:
The patent transforms the laser parameters from high pulse energy to high repetition rate with low pulse energy, enabling precise refractive structure formation without tissue damage. The high repetition rate allows for controlled, incremental modification of the refractive index, improving manufacturing precision while eliminating the harmful effects associated with high pulse energy.
3Adaptability or versatility
If traditional vision correction methods are used, then refractive errors can be corrected, but the ability to create complex patterned refractive structures is limited
Solution Approach 1:
The patent replaces traditional mechanical or chemical methods of vision correction with a laser-based optical system. The high repetition rate femtosecond laser enables the creation of complex patterned refractive structures through computer-controlled scanning, providing versatility in designing custom correction patterns while maintaining ease of manufacture through automated processing.
4Reliability
If high repetition rate low pulse energy lasers are used, then precise refractive structures can be formed without tissue damage, but the device complexity increases
Solution Approach 1:
The patent utilizes parameter changes by operating the laser at high repetition rates with low pulse energy, which fundamentally alters the interaction mechanism with tissue. This parameter transformation enables the use of commercially available femtosecond laser systems configured for high repetition rate operation, achieving precise refractive structure formation with reduced tissue damage while managing device complexity through optimized system configuration.
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
This method enables precise and non-invasive correction of refractive errors by creating refractive structures that can correct myopia, hyperopia, astigmatism, and higher-order aberrations without causing significant tissue damage, allowing for long-term alterations in refractive power and shape changes that can be tailored to individual vision needs.
Implementation Method 1
modifying the index of refraction of optical polymeric lens material or of ocular tissue in the eye by a high-repetition, low-pulse energy femtosecond laser
Implementation Method 2
The refractive structures are formed by scanning the laser over a select region of the optical tissue or polymeric material resulting in refractive optical structures
Data Source
AI summary
Methods and systems wherein laser induced refractive index changes by focused femtosecond laser pulses in optical polymeric materials or ocular tissues is performed to address various types of vision correction, and the laser induced changes to the refractive index avoid ablation and removal of the optical polymer materials while minimizing scattering losses.