Corneal Laser Treatment Using Ring-Shaped Tissue Extraction

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Solution Overview

Problem

Current methods for correcting refractive errors, especially in eyes with keratoconus, are invasive and risk further damaging the thin cornea, as they require minimum tissue removal and can cause complications like inflammation and increased susceptibility to trauma.

Innovation Solution

A treatment apparatus using a femtosecond or excimer laser controlled by a device that measures pachymetry and topography to cut out a volume in a closed ring, partial ring, or crescent shape from the cornea, allowing for gentle correction without reducing corneal thickness, and optionally using a protective mask to prevent laser damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a lenticule-shaped volume with minimum thickness is cut out from the cornea, then the corrected visus is maintained and complications are reduced, but the corneal tissue is further thinned and the risk of trauma increases

Engineering Contradiction:
Improvecorrected visusVSAvoidcorneal thickness
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent extracts only the necessary minimal tissue volume in a ring or partial ring shape from the cornea, rather than removing a full lenticule. This extraction approach maintains the structural integrity and thickness of the cornea while still achieving the refractive correction goal, thus preventing trauma and inflammation complications.

Inventive Principle:
Principle #2Taking out (Extraction)

2Strength

If intrastromal corneal ring segments are inserted to correct refractive error, then the corneal structure is reinforced, but inflammation occurs and the implant can grow out of the cornea

Engineering Contradiction:
Improvecorneal structureVSAvoidinflammation
Core Design Contradiction:
StrengthVSObject-generated harmful factors

Solution Approach 1:

The patent replaces the mechanical implant system with a laser-based tissue removal system. Instead of inserting foreign body ring segments that cause inflammation, the invention uses a laser to precisely remove minimal tissue in a ring shape, achieving structural reinforcement through controlled tissue removal and healing rather than through implant insertion.

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

3Reliability

If LASIK procedure is performed to correct refractive error, then vision is improved, but the cornea is further damaged and thinned

Engineering Contradiction:
Improvevision correctionVSAvoidcorneal integrity
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent applies local quality by removing tissue only in a specific ring or partial ring shape at a precise location in the cornea, rather than removing a large lenticule-shaped volume. This localized tissue removal achieves refractive correction while preserving the overall corneal thickness and structural integrity, avoiding the widespread thinning caused by traditional LASIK.

Inventive Principle:
Principle #3Local quality

4Reliability

If a protective mask is used during laser treatment, then the laser application is made precise and safe, but the device complexity increases

Engineering Contradiction:
Improvelaser application safetyVSAvoidsystem components
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent introduces a protective mask as an intermediary element between the laser device and the cornea. This mask serves as a physical barrier that defines the treatment area and prevents accidental laser damage to surrounding tissues, thereby enhancing safety without requiring complex control systems or advanced laser positioning mechanisms.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 method provides a gentle and effective correction of refractive errors without thinning the cornea, reducing the risk of complications and trauma, and can be used for thin corneas, with the protective mask ensuring precise and safe laser application.

Implementation Method 1

a laser device (14) for separating corneal tissue by means of laser radiation (16)

Methodology Applied
Scientific EffectLaser ablation: Laser Ablation

Implementation Method 2

cutting out and/or ablated a volume (24) out of a surface (20) of the cornea (22)

Methodology Applied
Scientific EffectAblation: Ablation

Data Source

PatentEP3135261B1Treatment apparatus for correcting a refractive error of an eye
Publication Date: 2021.01.27 CARRIAZO CESAR C
  • EP3135261B1 patent drawingFigure 1
  • EP3135261B1 patent drawingFigure 2
  • EP3135261B1 patent drawingFigure 3

AI summary

The invention relates to treatment apparatus (10) for correcting a refractive error of an eye (12) comprising: - a laser device (14) for separating corneal tissue by means of laser radiation (16); - a control device (18) designed to control the laser device (14) to emit the laser radiation (16) for cutting out and/or ablating a volume (24) out of the surface (26) of the cornea (22) of the eye (12) in dependency on a measured pachymetry and/or topography of the cornea (22) and the refractive error of the eye (12), whereby the cut-out and/or ablated volume (24) in the surface (20) of the cornea (22) results in a shape of a closed ring, a partial ring, a crescent or a crescent shaped closed ring. Furthermore the invention relates to a method for controlling such a treatment apparatus (10), and to a protective mask (40) for an eye (12).