femtosmile complications: how to avoidahmed yousry fekry, md. 3/16/2018 25 equation = famous names...

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Femto SMILE

Abdelmonem HamedFellow of Baylor college, TX, USA

Professor of ophthalmology,

Benha University, Egypt

I have no any financial interest from Zeiss co. or

from its agents and distributors

Femto SMILE

Abdelmonem HamedFellow of Baylor college, TX, USA

Professor of ophthalmology,

Benha University, Egypt

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Excimer laser Photoablation

The excimer Lasers produce UV light, that hits tissue , then

the Collagen molecules become excited and absorb photons & heat up, that lead to:

breaking of hydrogen bonds of tissue water, so water expand and undergoes a phase

transition into hot gas & burst out that burst out includes the tissue protein.

Femtolaser laser Photodisruption

Ionization of the electrons of the tissue by Femtolaser produce plasma

This plasma expands which lead to

pressure as high as 10 kilobars

that lead to creation of cavitation bubbles

that bubbles exert a cutting effect upon the tissues.

1 2 3

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Meaning of Femtosecond

• A femtosecond is the unit of time equal to • 10−15 (10 power negative 15) or• 1/1,000,000,000,000,000 of a second;

• Which means, one millionth of one billionth, of a second.

• A nanometer= 10−9

Femtosecond laser VS excimer laser7 advantages of femtolaser over Excimer laser

Femtolaser: Wave length = 1053fmExcimer laser: Wave length = 193nm

Results of these advantages Ultra-high precisionUltra-low collateral damageThe femtolaser has:

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SMILE

Advantages

AccuracyOf SMILE

SMILE

Advantages

AccuracyOf SMILE

Complete one machine

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SMILE

Advantages Accuracy

Complete one machine

It doesn’t get affected by humidity

Of SMILE

SMILE

Advantages Accuracy

Complete one machine

Better corneal biomechanics

It doesn’t get affected by humidity

Of SMILE

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SMILE

Advantages Accuracy

Complete one machine

Better corneal biomechanics

Complete femtolaser surgery

It doesn’t get affected by humidity

Of SMILE

SMILE

Advantages Accuracy

Complete one machine

Better corneal biomechanics

Complete femtolaser

Minimally invasive: 2-3 mm incision

It doesn’t get affected by humidity

Of SMILE

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SMILE

Advantages Accuracy

Complete one machine

Better corneal biomechanics

Complete femtolaser

It doesn’t get affected by humidity

Of SMILE

Better visual quality @ larger pupil diameter.

Minimally invasive: 2-3 mm incision

SMILE

Advantages Accuracy

Complete one machine

Better corneal biomechanics Complete femtolaser

It doesn’t get affected by humidity

Of SMILE

Better visual quality @ larger pupil diameter.

Minimally invasive: 2-3 mm incision

No dryness

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SMILE

Advantages Accuracy

Complete one machine

Better corneal biomechanics Complete femtolaser

It doesn’t get affected by humidity

Of SMILE

Better visual quality @ larger pupil diameter.

Minimally invasive: 2-3 mm incision

No dryness

No postop. Restriction.

SMILE

Advantages Accuracy

Complete one machine

Better corneal biomechanics Complete femtolaser

It doesn’t get affected by humidity

Of SMILE

Better visual quality @ larger pupil diameter.

Minimally invasive: 2-3 mm incision

No dryness

No postop. Restriction.

FDA approved

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Advantages Accuracy

Complete one machine

Better corneal biomechanics

Complete femtolaser

It doesn’t get affected by humidity

Of SMILE

Better visual quality @ larger pupil diameter.

Minimally invasive: 2-3 mm incision

No dryness No postop. Restriction. FDA approved

No lasik flap complications

SMILE

SMILE

Advantages Accuracy

Complete one machine

Better corneal biomechanics

Complete femtolaser

It doesn’t get affected by humidity

Of SMILE

Better visual quality @ larger pupil diameter.

Minimally invasive: 2-3 mm incision

No dryness No postop. Restriction. FDA approved

No lasik flap complications

No PRK complications

Haze

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Hyperopia correction is under research

Professor Dr. Osama Ibraheem

(Latest results of ReLEx for Hyperopia are quite encouraging)

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November 9, 2017

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It looks that, SMILE is better thanlasik, femto-lasik, and PRK

So, where the problem,what prevents SMILE from progress

?

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The major problems with ReLEX SMILE are

3. Difficult start up in the beginning of learning curve

1. Enhancement

2. Epith. ingrowth 4. Cost

1. Enhancement

A. Surface ablation (SMILE + PRK)B. Secondary SMILE (SMILE + SMILE)

I. Anterior to the 1ry. Procedure (Cap).II. Posterior to the 1ry. Procedure (Bed)

C. Covert the cap to flap, then followed by excimer ablation (SMILE + Femto-LASIK)

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• (SMILE +PRK)• induced corneal edema and haze (23±6 cells).

• It needs mitomycin-C in order to reduce inflammation.

• (SMILE + SMILE) offers advantages:• minimal inflammation (7±1 cells).

• maintaining a ‘flap-less’ surgery.

• 2ry lenticule is very thin.

• (SMILE + FEMTO-LASIK)• induces more inflammation (10±2 cells)

compared to (SMILE + SMILE).

(Rabbits)

• (SMILE +PRK)• induced corneal edema and haze (23±6 cells).

• It needs mitomycin-C in order to reduce inflammation.

• (SMILE + SMILE) offers advantages:• minimal inflammation (7±1 cells).

• maintaining a ‘flap-less’ surgery.

• 2ry lenticule is very thin.

• (SMILE + FEMTO-LASIK)• induces more inflammation (10±2 cells)

compared to (SMILE + SMILE).

(Rabbits)

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• (SMILE +PRK)• induced corneal edema and haze (23±6 cells).

• It needs mitomycin-C in order to reduce inflammation.

• (SMILE + SMILE) offers advantages:• minimal inflammation (7±1 cells).

• maintaining a ‘flap-less’ surgery.

• 2ry lenticule is very thin.

• (SMILE + FEMTO-LASIK)• induces more inflammation (10±2 cells)

compared to (SMILE + SMILE).

(Rabbits)

• (SMILE +PRK)• induced corneal edema and haze (23±6 cells).

• It needs mitomycin-C in order to reduce inflammation.

• (SMILE + SMILE) offers advantages:• minimal inflammation (7±1 cells).

• maintaining a ‘flap-less’ surgery.

• 2ry lenticule is very thin.

• (SMILE + FEMTO-LASIK)• induces more inflammation (10±2 cells)

compared to (SMILE + SMILE).

(Rabbits)

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• (SMILE +PRK)• induced corneal edema and haze (23±6 cells).

• It needs mitomycin-C in order to reduce inflammation.

• (SMILE + SMILE) offers advantages:• minimal inflammation (7±1 cells).

• maintaining a ‘flap-less’ surgery.

• 2ry lenticule is very thin.

• (SMILE + FEMTO-LASIK)• induces more inflammation (10±2 cells)

compared to (SMILE + SMILE).

(Rabbits)

• (SMILE +PRK)• induced corneal edema and haze (23±6 cells).

• It needs mitomycin-C in order to reduce inflammation.

• (SMILE + SMILE) offers advantages:• minimal inflammation (7±1 cells).

• maintaining a ‘flap-less’ surgery.

• 2ry lenticule is very thin.

• (SMILE + FEMTO-LASIK)• induces more inflammation (10±2 cells)

compared to (SMILE + SMILE).

(Rabbits)

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Secondary SMILE (SMILE + SMILE) enhancement

Anterior to the 1ry. Procedure o SMILE retreatment in cap.o 1st SMILE cap thickness must be > 160 µo It is a 2ry complete SMILE procedureo 2nd cap thickness must be not less than 100 µ

Cap 100 µ

2ry SMILE

1ST SMILE

Bed 250 µ

Cornea

Cap

Bed

Secondary SMILE (SMILE + SMILE) enhancement

Posterior to the 1ry. Procedure (case report, Donate and Thäeron, 2015 JRS)o SMILE retreatment in

stromal bedo Minimum residual stromal

bed after 2ry SMILE must

be not less than 250 µ

o Good centration with Dr.

Sedky marker

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Secondary SMILE (SMILE + SMILE) enhancement

Posterior to the 1ry. ProcedureAfter docking and

starting the laser get

your foot off the laser

pedal after doing the

side cut of the

lenticule.

We don’t need the

cap creation step.

2. Epithelial ingrowth?

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Epithelial ingrowth?

SMILE with 2incisions?

Panel discussion

Epithelial ingrowth?

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Epithelial ingrowth?

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Pt. OLD SMILE pass

Circle pass

Junction

Circle pass

Diameter of circle 3 mm bigger than cap

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Circle has the same thickness like the cap

SMILE incision position @ 120

Circle hinge position @ 70

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This was my 1St Case

3. To facilitate the start up in the beginning of

the learning curve

We created a new technique called:

(ReSMILE): Push-up and push-down techniques,

Abdelmonem Hamed, MD

Ahmed Yousry Fekry, MD

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Equation =

Famous names of femto-smile:

1. (ReLEx)

2. (SMILE)

Refractive + SMall-Incision + Lenticule Extraction

= Refractive SMall Incision Lenticule Extraction

(ReSMILE)

3. Difficult start up in the beginning of learning curve

Refractive

SMall-IncisionLenticule Extraction

Lenticule Extraction

(ReSMILE): Push-up and push-down techniques

ReSMILE: Push-up technique

Benha University

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ReSMILE: Push-up technique

Benha University

ReSMILE: push-down technique

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Restrictions & Complications

Myopia up to -10.0 D

Astigmatism up to -5.0 D.

Cap or lenticule rupture

Cap lamellar keratitis

Limited to the cap, not the bed

Less responsive to corticosteroid therapy

What about double SMILE?

Rainbow glare

Due to micro-irregularities of the interface.

Transient Light Sensitivity Syndrome (TLSS)

Good visual acuity + Photophobia

Usually resolves with days to weeks

Restrictions & Complications

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VisionMy vision for the future is:

The SMILE is going to replace all the old refractive procedures , however it needs A hard research work for

optimization.

The refractive surgeons should be convinced by the SMILE, to be able to overcome the resistance of the change.

Resistance to change

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Thank you very much