dr. eskina foz presentation escrs

7/25/2019 Dr. Eskina FOZ Presentation ESCRS

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Erika N. Eskina, MD1

,Victoria Parshina1,Olga Mironenko, PhD1

Yuri Kolmakov1

Samuel Arba-Mosquera, PhD2,*

(1) Laser Surgery Clinic SPHERE, Moscow, Russi

(2) SCHWIND eye-tech-solutions, Kleinostheim, Germ

FINANCIAL DISCLOSURE:

The authors have no financial or proprietary interest in a product, method, or material described.Dr. Arba Mosquera and Thomas Magnago are employees of SCHWIND eye-tech-solutions.

Aspherical optical zones:

The effective optical zone with the Schwind


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Purpose:To evaluate the functional optical zone (FOZ) and influencing parameters among eyes that u

treatments for myopic astigmatism with PRK , TransPRK or LASIK.

Settings:

Prof. Erika N. Eskina, MD, Laser Surgery Clinic SPHERE, Moscow, RussiMethods:

16 patients (32 eyes) treated with

16 patients (32 eyes) treated with

16 patients (32 eyes) treated with LASIK using Pendular microkeratome (SCHWIND eye

using the SCHWIND AMARIS flying-spot excimer laser system (SCHWIND eye-tech-solutionsix-month.

We analysed the influence of the following parameters:

OZ Planned, FOZ preop, K readings in 4 mm zone preop, SPH inputted, CYL inputted, pachy

of the cornea, age and type of operation


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Parameters and Statistics

Clinical outcomes were evaluated in terms of functional optical zone (FOZ), eff

zone (EOZ), planned optical zone (POZ),

POZ=Optical zone selected in the software where the full amount of refractive

applied.

FOZ = defined as the area (diameter) where the RMS HO value exceeds 0.50D th

search starts from the center to the periphery of each map).

EOZ = post-op FOZ

Multilinear regression analyses started with full degrees of freedoapplied stepwise regression

a P value less than 0.05 was considered statistically significan

We also used Ordinary least square method, Mann-Whitney U-t

Coefficient of determination (R2) and Wilcoxon signed-rank te


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Group description


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RESULTS - Optical Zone

The level of significance in difference in OZ postOp and planned TransPRK and PRK g

For PRK and LASIK groups is 9%

For LASIK and TransPRK is 68% (not significant at all)

OZ PostOp OZ Planned OZ PreOp

Planned OZ

deviationChange of OZ

postop


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P

POZ deviation in a relation to ablation depth and E


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POZ deviation in a relation to K readings and EOZ


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RESULTSEOZ (planned) deviation in TransPRK Grou

Scattergramm represents the reduction in the effective OZ in majority of

3

4

5

6

7

8

9

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31

OZ,mm

CASES

OZ plan OZ post OP

3

4

5

6

7

8

9

3 4 5 6

OZpostOP

OZ plan


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RESULTSEOZ (planned) deviation in PRK Group

3

4

5

6

7

8

9

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31

OZ,mm

CASES

OZ plan OZ post OP

3

4

5

6

7

8

9

3 4 5 6

OZpostOP

OZ plan

Scattergramm represents the reduction in the effective OZ in all cas


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3

4

5

6

7

8

9

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

OZ,mm

CASES

OZ plan OZ post OP

3

4

5

6

7

8

9

3 4 5 6

OZpostOP

OZ plan

RESULTSEOZ (planned) deviation in LASIKGroup

Scattergramm represents the reduction in the effective OZ in majority of


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Multip

an


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EOZ planning

EOZpostOP = 3.144 + 0.688*OZ0.170*OZpreOP

i + 0.393*SPH

i + 0.17

0.003*PACHi0.058*K2i0,008*Agei+ 0.0.461*D2i

where:

OZplanOZ planned, PACHpachymetry in the center of the coreading in the flat meridian;Agepatient age; D1is a binary pathere is a PRK planned,0if there is other type of surgery plann

binary parameter =1 if there is a TransPRK planned, 0 if there issurgery planned


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EOZ planning

C


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Conclusion The results of the analysis offer us a possibility to make a real planning of OZ postop and incr

optics for patienrs operated

The mathematical modeling of the factors, which influencing the EOZ could be described by th

EOZpostOP = 3.144 + 0.688*OZplan + 0.170*OZpreOPi+ 0.393*SPHi+ 0.

0.003*PACHi0.058*K2i0,008*Agei+ 0.319*D1i+ 0.461*D2

Take home message:

Decreasing of EOZ means only higher, than was planned, level of aberr

ablation

EOZ decreasing with increasing a level of myopia and astigmatism.

Planning an additional 1 mm OZ you should input at least for PRK 1,13 m

1,09 mm and for LASIK 1,06 mm


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Thank you for your kind attention

dr. eskina foz presentation escrs

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