Bowman Layer Graft Shaping for Corneal Aberration Correction

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Solution Overview

Problem

The existing methods for harvesting the Bowman membrane layer for corneal transplantation are challenging, have a high failure rate, and often introduce new visual defects or require additional treatments to correct for existing aberrations.

Innovation Solution

A method involving an eye surgical device, such as a femtosecond laser or microkeratome, is used to cut the Bowman membrane layer with a predefined layer of stromal tissue attached, which is then customized based on recipient eye visual defect data to correct aberrations and refractive errors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the Bowman membrane layer is harvested using manual techniques, then the transplantation can be performed, but the preparation process is challenging with high failure rate

Engineering Contradiction:
Improvepreparation success rateVSAvoidpreparation difficulty
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent replaces manual mechanical harvesting techniques with a femtosecond laser system that uses photodisruption to precisely separate the Bowman membrane layer from the stroma. This substitution of mechanical manual techniques with optical laser technology eliminates the challenges of manual dissection and significantly reduces the failure rate of Bowman layer harvesting.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Adaptability or versatility

If the Bowman membrane layer is transplanted without stromal tissue, then the transplantation is simpler, but visual defects and aberrations cannot be corrected

Engineering Contradiction:
Improvecorrection capabilityVSAvoidtransplantation complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent merges the Bowman membrane layer harvesting with refractive correction by using the same femtosecond laser to both separate the Bowman layer and customize the stromal layer with aberration corrections. This combines two procedures into one, allowing visual defect correction to be integrated into the transplantation process without requiring separate surgical interventions.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent performs preliminary customization of the stromal layer during the harvesting phase, using visual defect data from the recipient eye to pre-shape the stromal tissue before transplantation. This preliminary action ensures that the corrective function is built into the graft itself, eliminating the need for subsequent corrective procedures.

Inventive Principle:
Principle #10Preliminary action

3Manufacturing precision

If a thicker layer of stromal tissue is attached to the Bowman membrane layer, then customization precision is improved, but the harvesting becomes more difficult

Engineering Contradiction:
Improvecustomization precisionVSAvoidharvesting difficulty
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The femtosecond laser system replaces manual harvesting techniques, enabling precise separation of the Bowman membrane layer with an optimized thickness of stromal tissue (10-20 micrometers). The laser's photodisruption mechanism allows controlled creation of this specific thickness without the difficulty and imprecision of manual dissection, achieving both the desired thickness for customization and ease of harvesting.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 reduces preparation failures and ensures precise correction of visual defects without additional tissue sacrifice, enhancing treatment satisfaction.

Implementation Method 1

The eye surgical device is a femtosecond laser, and the customization of the remaining stromal tissue is performed through a cut located posteriorly to the Bowman membrane layer of the donor eye by the femtosecond laser

Methodology Applied
Scientific EffectPhotodisruption:

Implementation Method 2

the Bowman membrane layer with the attached layer of stromal tissue may be cut in the donor eye, extracted from the donor eye and then processed, for example by a laser, in particular by an ablation laser, to customize the stromal layer

Methodology Applied
Scientific EffectAblation: Ablation

Data Source

PatentEP4649926A1Treatment apparatus and method for providing a bowman membrane layer transplant
Publication Date: 2025.11.19 SCHWIND EYE TECH SOLUTIONS GMBH
  • EP4649926A1 patent drawingFigure 1
  • EP4649926A1 patent drawingFigure 2
  • EP4649926A1 patent drawing

AI summary

The invention relates to a treatment apparatus and a method for providing a Bowman membrane layer transplant. The method comprises the steps of cutting the Bowman membrane layer (18) from a donor eye (12) by an eye surgical device (22), wherein the cut is performed such that a predefined layer of stromal tissue (32) remains attached to the Bowman membrane layer (18); wherein the remaining stromal tissue (32) of the Bowman membrane layer (18) is customized depending on visual defect data of a recipient eye for the Bowman membrane layer transplant; and providing the Bowman membrane layer (18) with the customized stromal tissue (32) as a transplant for the recipient eye.