Corneal Post-Treatment Planning for Epithelial Thickness Changes

Solution Overview

Problem

Existing methods for refractive correction in eye surgery, such as SMILE, face challenges in accurately planning follow-up treatments due to changes in corneal thickness, particularly epithelial thickening, which can lead to inaccuracies in incision positioning and incomplete lenticule extraction.

Innovation Solution

A planning device and method that account for changes in corneal thickness, specifically epithelial thickening, by using measurement devices like OCT or ultrasound to determine and adjust control data for laser incisions, ensuring precise alignment and correction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If follow-up treatment is performed without accounting for epithelial thickening, then treatment planning is simpler, but incision positioning becomes inaccurate

Engineering Contradiction:

Improvetreatment planning complexityVSAvoidincision positioning accuracy

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The planning device performs preliminary calculation of epithelial thickening effects before treatment planning. By predicting the thickness change in advance and incorporating it into the treatment plan, the system eliminates the need for complex post-treatment measurements and adjustments, thereby maintaining simplicity while ensuring accuracy.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system incorporates feedback mechanisms by using measured or calculated epithelial thickness changes to adjust treatment parameters. The planning device continuously monitors and adjusts the treatment plan based on the predicted epithelial thickening, ensuring accurate incision positioning without requiring complex manual interventions.

Inventive Principle:

Principle #23Feedback

2Productivity

If epithelial thickening is not considered in treatment planning, then planning process is faster, but lenticule extraction becomes incomplete

Engineering Contradiction:

Improveplanning process speedVSAvoidlenticule extraction completeness

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The system performs preliminary calculation of epithelial thickening effects before finalizing the treatment plan. By predicting the thickness change in advance and incorporating it into the treatment plan, the system eliminates the need for complex post-treatment measurements and adjustments, thereby maintaining simplicity while ensuring accuracy.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system incorporates feedback mechanisms by using measured or calculated epithelial thickness changes to adjust treatment parameters. The planning device continuously monitors and adjusts the treatment plan based on the predicted epithelial thickening, ensuring accurate incision positioning without requiring complex manual interventions.

Inventive Principle:

Principle #23Feedback

3Power

If standard treatment planning is used without thickness adjustment, then computational requirements are lower, but refractive correction accuracy deteriorates

Engineering Contradiction:

Improvecomputational power requirementsVSAvoidrefractive correction accuracy

Core Design Contradiction:

PowerVSManufacturing precision

Solution Approach 1:

The system performs preliminary calculation of epithelial thickening effects before treatment planning. By predicting the thickness change in advance and incorporating it into the treatment plan, the system eliminates the need for complex post-treatment measurements and adjustments, thereby maintaining simplicity while ensuring accuracy.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The planning device adjusts treatment parameters based on predicted epithelial thickening. By dynamically modifying incision depth and positioning parameters according to the calculated thickness changes, the system maintains high refractive correction accuracy without requiring excessive computational resources.

Inventive Principle:

Principle #35Parameter changes

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

Enhances the accuracy of follow-up treatments by minimizing errors in incision planning, ensuring complete lenticule extraction and maintaining optimal refractive correction.

Implementation Method 1

When creating corneal incisions using laser radiation, the optical effect of the radiation is typically exploited by generating an optical breakthrough through individual optical pulses with durations ranging from approximately 100 fs to 100 ns.

Methodology Applied

Scientific EffectOptical breakthrough: Laser Ablation

Implementation Method 2

A planning device and method that account for changes in corneal thickness, specifically epithelial thickening, by using measurement devices like OCT or ultrasound to determine and adjust control data for laser incisions

Methodology Applied

Scientific EffectOptical coherence tomography: Tomography

Data Source

PatentEP3618787B1Post-treatment in refraction correction during eye surgery

Publication Date: 2026.02.25 CARL ZEISS MEDITEC AG

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Figure 6(a)~6(b)

AI summary

The invention relates to a planning device for generating control data, a treatment apparatus for refraction correction eye surgery and to a method for generating control data for such a treatment apparatus which allows an improved subsequent refraction correction. The planning device comprises calculation means for defining a cut surface of the cornea for post-treatment, wherein the calculation means are designed such that a change of thickness of the epithel is taken into account in the calculation, which was caused essentially by a pretreatment.