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Early recovery after simultaneous

bilateral PhotorefractiveKeratectomy for Myopia

Rami Cohen1

, David Varssano2

,Deborah Schimmel3 and David Zadok41 Sackler School of Medicine, Tel Aviv University,2 Department of Ophthalmology, Tel Avivmedical center and Sackler School of Medicine, Tel Aviv University, 3 Department ofOphthalmology, Rabin medical center, Petah Tiqua and Sackler School of Medicine, TelAviv University 4 Department of Ophthalmology, Assaf Harofeh Medical Center, Zerifin, andSackler School of Medicine, Tel Aviv University

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The authors acknowledge no

financial interest in the subjectmatter of this presentation

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Once upon a time

Radial Keratotomy

Automated Lamellar Keratotomy

Some effect Some predictability

Some disasters

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Late 1980s

Photorefractive Keratectomy

High precision

Stable results Superior to RK, ALK

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Early 1990s

Photorefractive Keratectomy

Painful

Slow recovery Haze

Regression

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Mid 1990s

Laser In Situ Keratomileusis

No pain

No time Simultaneous

Wow effect

Superior to PRK

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Early 2000s

Laser In Situ Keratomileusis

Keratoectasia

Diffuse lamellar keratitis Flap stability

Back to the surface?

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Why PRK now?

Excimer laser improvement

Scanning small spot

Gaussian energy distribution Eye trackers

Tissue saving algorithm

Wider treatment zoneCornea(top view)

2 mm

Spots

1 mm

SpotsOptical zone

6.5 mm

11 mm

Diameter

Gaussian ablation profile Tophat ablation profile

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Why PRK ???

No flaps

No steel blade flaps

No laser explosion flaps

Thicker residual stromal bed

No flap dislocation

No striae

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Purpose

To assess the early visual and

refractive recovery after

simultaneous bilateral PRK usinga modern flying small spot laser.

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Setting

Refractive surgery facility

Allegretto 200Hz excimer laser(WaveLight

Laser Technologie AG, Erlangen,Germany)

ALLEGRETTO

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Method

Prospective nonrandomized clinical trial

Two surgeons (DV, DZ)

Simultaneous bilateral myopic PRK Emmetropia was the goal for all eyes

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Patient Data

162 consecutive myopic eyes (81 patients)

Age

30.12 7.74 (range 18 to 52 years) Gender

51% female, 49% male

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Patient Data

Mean preoperative sphere

- 3.02 1.57 D (range, - 0.75 to -7.75 D)

Mean preoperative astigmatism-0.71 0.73 D (range, 0.00 to -3.50 D)

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Patient Data

Contact lens history

SCL: 65%, RGPCL: 5%

Contact lens wear duration7.93 6.90 years (range 2 months to 32 years)

Stopped CL use

376 1148 days (1 week to 20 years; median27 days)

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Patient Data

IOP

13.38 2.37 (range 8 to 19 mmHg)

CCT530.40 34.62 (range 453(!) to 632 micron)

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Outcome Measures

Main outcome measures uncorrected visual acuity (UCVA)

at 1 week

at 1 month

Secondary outcome measures Manifest refraction

at 1 week

At 1 month after surgery

Best corrected visual acuity at 1 month Haze at 1 month

IOP at 1 month

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Secondary

Outcome Measures

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Results - Manifest refraction

Manifest refraction at 1 week

Mean sphere

0.33 0.62D (range,- 1.75 to 2.75 D)

Mean postoperative astigmatism

-0.87 0.53D (range,- 2.5 to 0 D)

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Results - Manifest refraction

Manifest refraction at 1 month

Mean sphere

0.18 0.45D (range,- 1.25 to 1.25 D)

Mean postoperative astigmatism

-0.54 0.37D (range,- 1.5 to 0 D)

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Results Manifest Spherical Equivalents

-1.00

2.00

0.88

-8.25

-2.13-1.75

-3.38

-0.11 -0.09

-10.00

-8.00

-6.00

-4.00

-2.00

0.00

2.00

4.00Preoperative 1 Week post 1 Month post

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Results Haze and IOP at 1 month

Trace

61%

None

27%

+1

12%

Haze Intra OcularPressure

13.38

15.20

0

2

4

6

8

10

12

14

16

18

20

Before After

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PrimaryO

utcome Measures

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Results - 1 week postoperative UCVA

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Results - 1 month postoperative UCVA

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Conclusions

Traditional PRK performed utilizing a

modern excimer laser provides fast visual

rehabilitation for most patients

The gap in speed of visual recovery

between surface ablation and LASIK

seems to narrow

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Thank you!