solid-state technologybasics. 6 marcel kirsch 28.09.05. 7 marcel kirsch 28.09.05 by now excimer...

Solid-State Technology

The future in refractive surgery

OptecBB workshopPhotonics for medical Technologies

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Marcel Kirsch28.09.05

Outline

• Company

• Basics

• Why solid-state laser approach?

• Certified and available Product LASERSOFT

• Advantages for patients and surgeons

• Clinical data

• Conclusions

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Company

•Located in Kleinmachnow, SW of Berlin

•Development and production of Systems for Laser-Vision-Correction utilizing a Solid State Laser Platform

•Based on developed and developing proprietarytechnology to deliver best in class products

•Katana owns exclusive, innovative, patentedtechnologies in the solid state laser field and applicationto refractive surgery

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Basics

link

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Refractive surgerychanging the shape of the corneaby removing tissue to correct-nearsightedness (myopia)-farsightedness (hyperopia)-astigmatism

•More myopia than hyperopia

Basics

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By now Excimer lasers are used:

UV pulse generation in an Excimer laser

high voltagepulse

UV pulses

@ 193 nm

Ar

F

Ar F*

Gas discharge tends to InstabilitiesDepends on the gas mixture

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Why solid-state laser approach?

Solid State Laser Crystals used as Laser medium§ Inexpensive to operate - no toxic gas (Excimer) anymore

Diode pumping provides long lifetime and high efficiency§ cw pumping, high shot to shot and long term stability§ stable energy and beam pointing (precise ablation rate).§ no high voltage gas discharge involved (Excimer)

High repetition rates up to 2kHz (Katana)§ less energy per pulse (heating)§ less shock waves (collateral distructions)§ treatment in a silent, patient-reassuring environment

Laser characteristics

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UV pulse generation in the all solid statediode pumped laser (highly stable)

Lasercrystal

Conversion 2Conversion 1

Modu-

lator

UV pulses

@ 210 nm

cw-pump

diodes

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Excellent (intrinsic Gaussian) beam spot distribution§ high quality of the ablated surface

Why solid-state laser approach?Beam characteristics

Small spot size§ important for fine-structured ablation

Highly collimated beam§ fast scanning, no strong focussing

DSSL are excellent candidates for true scanning small spot lasers for LVC

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Lasersoft(CE-certified)

CompactMobile200 kgFlying spot

Solid State LaserTechnology

for LVC

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Specifications

0.7-1mm

Repetition Rateup to 400Hz

Speed of Eye Tracking

few 250Hz(video based)

Spot Size

multimodeadditional opticsfor Gaussian profil

single mode (gauss.)smooth surface

Excimer (193 nm) LaserSoft (210 nm)

Beam Quality0,20 mm

Up to 2kHz !!

>1 kHz

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The advantages of the LaserSoft system can be differentiated into:

•Technical Advantages

•Clinical Advantages

•Economical Advantages

All of those are linked together in certain ways

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Technical advantages:

•Small spot size allows complex ablation profiles

•Low sensitivity to environmetal influences

•Fast and easy-to-use Eyetracker

•Intuitive and straightforward software

•Easy to setup

•Low weight, small dimensions

•Optics with high life expectancy

•No noise

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This shows the relation of spot sizes

Broad beam laser (7mm)

Scanning (flying) spot laser

Lasersoft Solid State Laser

The volume ablated is to thesquare of the diameter

Example: a spot with 0,5 mm diameterAblates 4 times less volume than a spot with 1 mm

Lasersoft ablates 16 times less tissue per spot than a Scanning (flying) spot excimer laser.Hence 16 times more resolution

Comparison of spot sizes

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•Small spot size creates very detailed contours

•210 nm Wavelength passes through water and BSS

•Soft ablation creates a very smooth surface with

fast healing

•Fast and accurate eyetracker

•Aspheric ablation profile

Clinical advantages

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210 nm Wavelength passes through water and BSS

•Water and BSS (Balancedsaline solution) absorbs thewavelength of 210nm ca. 40times less than the 193nmused by excimer lasers.

•fluid on the corneal stromahas little or no effect on theablationrate

•Changes of the ambienthumidity do not affect theablationrate.

210 nm Relative Ablation Rate

0

25

50

75

100

0 2 4 6 8 10

Fluid path length [ mm ]

Re

l. A

bla

tio

n r

ate

[

% ]

H2OBSS

193nmin water

0,25mm (not to scale)

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Economical advantages

•No laser gas, no filters

•Long optics lifetime for SSL, less maintenance costs

•Easy to service and little downtime

•No special „Excimer grade“ room requirements neccessary

•System is mobile within the location and completely mobile on request

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Cinical data

myopia and myopic astigmatism

244 eyes

mean refractive error sf.eq. -3,08D +/- 2

max sf.eq. -11D

hyperopia and hyperopic astigmatism

58 eyes

mean refractive error sf.eq. +1,9D +/- 1,13

max sf.eq. +6,13D

mixed astigmatism19 eyes

mean refractive error sf.eq. -0,31D +/- 0,66max sf.eq. +2 D; min sf.eq. -4,50D

TOTAL TREATMENT185 patients - 322 eyes

mean age 37+/- 13 mean refractive error sf.eq. -2,03D +/- 2,66

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Solid-State laser system LASERSOFT

Incorporates the big advantages made over thelast years in the laser and photonic technology

Refractive surgery without gas

Next generation laser

Conclusions

Future for frequency-shifted DSSL inRefractive Laser Surgery

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Enjoy theFreedom of Vision!

Katana International AGEuroparc Dreilinden, Albert-Einstein-Ring 7D-14532 Kleinmachnow, GERMANY

Thank You

solid-state technologybasics. 6 marcel kirsch 28.09.05. 7 marcel kirsch 28.09.05 by now excimer...

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