Ring simulator : Principles and

interests

H. Kamoun

Introduction

Predicting the post-op results of ICRS is everycorneal surgeon’s dream.

Our objective: improving the predictibility of the results using topographic simulations of ICRS treatment.

Ring simulator :Problematic

The miss understanding of mecanism of action of different ring models.

The unpredictibility of the results: the corneal reaction is different from case to case.

«the Surprise effect »

How to get started ?

In the very begining we have tried to calculatethe average effect of each ring to makesimulations

Wrong channel

the corneal response to the ring differs from one

cornea to an other and basicly dépends on 2 reasons:

- Cornel factors: K, Pachy,age .. Ect

- Extra-corneal factors : related to the surgery

channel: centering ,depth ,diameter and width …..ect .

The solution ?Conceive an expert software.

Topographic module based on experience. « An expert sofware»

Using a refractive and topographic database of treated patients .

nothing is worth the experience of an eyeto find out about another with similar

characteristics

The adventure of Ring smulator

started in 2011

The big companies did not see any financial interest « few users »

We decided to develop this software alone with local engineers.

It took us 2 years of research.

Project : Ring Simulator

HOW TO ENTER A CLINICAL CASE

PRE-OP TOPOGRAPHY POST-OP TOPOGRAPHY

DIFFERANTIAL TOPOGRAPHYCALCULATED BY THE SOFTWARE

List of clinical cases

Simulation

Simulation

LIST OF CLINICAL CASES CLOSER TO THE ONE YOU’RE WORKING ON. THAN YOU CHOOSE THE CLOSEST ONE FOR SIMULATION.

.

Simulation

Ring simulators: the principles

Universal software :Adaptable to almost all topographers .

Digitizing and interpreting the database using the colour scale.

the software automatically detects the majority of the topographers scale.

Smart software Using a database of treated cases .

The more the database is important, the more performing it will be.

It integrates the Keraring nomogramalong with more suggestions and advice.

Ring simulators: the principles

Exemple 1 :KK stade 3/ K max 53D

Ref: Myopie: 3D / Cyl: 5D

Keraring SI6 :6mm 300μm/ 150°

Exemple 1 :KK stade 3/ K max 53D

Ref: Myopie: 3D / Cyl: 5D

Keraring SI5 :5mm 300μm/ 160°

REAL POST-OP TOPO TOPO POST OP SIMULATED

Exemple 2 :KK stade 2/ K max 49D

Ref: Myopie: 1 / Cyl: 3.5D

Keraring SI6 :6mm 200μm/ 150°

TOPO POST OP REELLE TOPO POST OP SIMULATED

Exemple 3 :KK stade 3/ K max 57D

Ref: Myopie: 7D / Cyl: 9D

Keraring SI5 5mm 160° 300μm / 120° 250μm

TOPO POST OP REELLE TOPO POST OP SIMULATED

Exemple 4 :KK stade 3/ K max 55D

Ref: Myopie: 1D / Cyl: 8D

Keraring 2X SI6 6mm 150° 300μm

TOPO POST OP REELLE TOPO POST OP SIMULATED

Conclusion

Ring simulator

It’s a valuable tool in the choice of the indication .

In my practice it allows :

- to choose the adapted ring models

- the best axes

The simulated topographies are very close to the real post op topographies in 95% of cases on the condition to choose a similar case.

Conclusion

Ring simulator

The need to enlarge the databasewith a greater number of cases to increase reliability.

Multicentric evaluation is needed to validate this software.

Thank you