Corneal Cross-Linking Laser Scanning for Oxygen Replenishment
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Solution Overview
Problem
Current cross-linking treatments for the eye, such as those for keratoconus and post-LASIK ectasia, face challenges in optimizing the photoactivation of cross-linking agents to achieve effective cross-linking activity while minimizing oxygen depletion and ensuring uniform treatment.
Innovation Solution
The use of a laser light source with a scanning system to deliver a scanned light pattern, optimizing parameters such as treatment time, total dose, intensity, pulsing, spot size, and repetition frequency, to enhance cross-linking activity based on photochemical kinetic reactions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If continuous laser irradiation is applied to achieve sufficient cross-linking activity, then cross-linking efficacy is improved, but oxygen depletion occurs which limits further cross-linking
Solution Approach 1:
The patent applies periodic pulsed irradiation instead of continuous laser exposure. The laser delivers photoactivating light in repeated pulses with intervals between them, allowing oxygen to replenish during the off-periods while still achieving cumulative cross-linking effect during the on-periods. This periodic action resolves the contradiction by maintaining oxygen availability while ensuring sufficient cross-linking activity accumulates over time.
2Productivity
If high laser intensity is used to reduce treatment time, then productivity is improved, but oxygen consumption rate increases leading to premature depletion
Solution Approach 1:
The patent uses pulsed laser delivery where high intensity is applied intermittently rather than continuously. Each pulse delivers sufficient energy to drive cross-linking reactions, but the intervals between pulses allow oxygen to diffuse back into the treatment zone. This maintains high productivity during pulse delivery while preventing premature oxygen depletion through periodic cessation of oxygen consumption.
Solution Approach 2:
The patent applies oxygen supplementation before and during the laser treatment process. By pre-saturating the corneal stroma with oxygen and maintaining oxygen supply during pulsed irradiation, the system ensures sufficient oxygen is available to support high-intensity laser pulses that would otherwise deplete oxygen too rapidly. This preliminary preparation of oxygen reserves enables higher productivity without compromising oxygen availability.
3Manufacturing precision
If the laser beam covers the entire corneal surface uniformly, then treatment uniformity is improved, but the treatment time increases due to the large area to be scanned
Solution Approach 1:
The patent segments the corneal treatment area into multiple discrete scan locations rather than attempting to illuminate the entire surface simultaneously. The laser beam is scanned to sequentially treat multiple discrete points or small regions across the cornea. This segmentation allows uniform treatment to be achieved at each location while reducing the total treatment time by treating smaller areas sequentially rather than requiring simultaneous illumination of the entire corneal surface.
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 approach allows for more efficient and uniform cross-linking of corneal collagen, improving treatment efficacy and stability, while also optimizing oxygen replenishment to prevent depletion.
Implementation Method 1
The photoactivating light causes the cross-linking agent in the one or more exposed regions to react with oxygen to generate cross-linking activity in the one or more exposed regions
Data Source
AI summary
A system for treating an eye includes a laser light source providing photoactivating light. The system includes a scanning system to receive the photoactivating light as a laser beam and to move the laser beam over a cornea treated with a cross-linking agent. The system includes a controller that provides control signal(s) to programmatically control the laser light source and the scanning system. The control signal(s) cause the laser beam to visit region(s) of the cornea more than once according to a scan pattern and expose the region(s) to the photoactivating light. The photoactivating light causes the cross-linking agent in the exposed region(s) to react with oxygen to generate cross-linking activity in the exposed region(s). The scan pattern causes a predetermined period of time to pass between visits by the laser beam to the exposed region(s), the predetermined period of time allowing oxygen in the exposed region(s) to replenish.