Presentation of Detlev Breyer (MD) at the ASCRS 2017 in Los Angeles. Title: Impact of increased PTA values on Visual Outcomes One Year after Refractive Lenticule Extraction (ReLEx) SMILE.

1. Impact of increased PTA values on Visual Outcomes One
Year after Refractive Lenticule Extraction (ReLEx) SMILE.
D. Breyer, H. Kaymak, K. Klabe, P. Hagen, F. Kretz, G. Auffarth

2. Financial Disclosure
Breyer, Kaymak & Klabe Eye Surgery and Premium Eyes are Consulting, Study Center & MAB for:
Abott, Alcon, AlimeraSciences, Allergan, AMO, Bayer, Carl Zeiss Meditec, Ellex, Fluoron, Geuder, iOptics, LensAR,
Novartis, Oculentis, Oertli, Revision Optics, Santen, Staar Surgical, Thea, Topcon, Visufarma, Ziemer

3. Cornea
Lenticule
Cap
3
PTA = Percent Tissue Altered
= (a + b)/c
a = cap thickness
b = max. lenticule thickness
c = central corneal thickness
PTA ≥ 40% was suggested a negative prognostic factor for
late keratectasia after LASIK surgery!
Santhiago MR et al. Association between the percent tissue altered and post-laser in situ
keratomileusis ectasia in eyes with normal preoperative topography.
Am J Ophthalmol. 2014 Jul;158(1):87-95
Question: Does this also apply for ReLEx SMILE treatment?
 Restrospectively compare 2 groups:
• ReLEx SMILE with PTA < 40%
• ReLEx SMILE with PTA ≥ 40%
Theoretical Background: PTA
Traget refraction in all eyes: Emmetropia
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4. Materials and Methods: Preoperative Patient Data
PTA<40% PTA≥40%
Number of eyes 313 373
Number of patients 189 213
mean
± stdv
min : max
mean
± stdv
min : max p-value
Age [years] 33.8 ± 8.0 20.0 : 72.0 34.2 ± 7.3 21.0 : 54.0 0.42
Sphere [D] -2.65 ± 1.27 -6.25 : 0.75 -4.98 ± 1.63 -9.75 : -1.25 <0.001
Cylinder [D] -0.57 ± 0.65 -3.00 : 0.00 -0.84 ± 0.70 -3.50 : 0.00 <0.001
SE [D] -2.94 ± 1.25 -7.13 : -0.13 -5.40 ± 1.57 -10.00 : -2.00 <0.001
CDVA [logMAR] -0.03 ± 0.05 -0.18 : 0.19 -0.01 ± 0.05 -0.16 : 0.26 <0.001
UDVA [logMAR] 0.94 ± 0.32 0.07 : 1.30 1.22 ± 0.19 0.02 : 1.30 <0.001
CCT [µm] 552 ± 32 486 : 637 541 ± 31 469 : 631 <0.001
Cap thickness [µm] 131 ± 11 120 : 150 136 ± 12 110 : 150 <0.001
Lenticule thickness [µm] 69 ± 15 39 : 110 109 ± 22 52 : 164 <0.001
PTA [%] 36.3 ± 2.4 29.7 : 40.0 45.2 ± 3.7 40.0 : 54.4 <0.001
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5. Examinations
(up to 3 years postop.):
• Manifest refraction
(Phoropter)
• Corrected & uncorrected
distant visual acuity
(ETDRS reading charts)
• Wafefront analysis
(KR-1W, Topcon)
• Scheimpflug Tomography
(Pentacam HD, Oculus)
• Patient questionnaire
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Materials and Methods: Postoperative Examinations

6. 0%
25%
50%
75%
100%
loss3
ormore
loss2
loss1
unchanged
gain1
gain2
gain3
ormore
Percentageofeyes[%]
∆CDVA [Snellen Lines]
Safety: monocular CDVA(post) - CDVA(pre)
1M (n=227)
3M (n=79)
6M (n=69)
1-3Y (n=87)
1M (n=275)
3M (n=94)
6M (n=77)
1-3Y (n=84)
• No significant (p<0.05) differences at any follow-up in terms of safety
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Results: Safety
PTA<40%PTA≥40%
PTA<40% PTA≥40%
ΔCDVA
[logMAR]
mean ±
stdv
mean
± stdv
p-value
1M 0.00 ± 0.07 0.00 ± 0.08 0.89
3M -0.01 ± 0.07 -0.01 ± 0.08 0.56
6M -0.01 ± 0.07 -0.02 ± 0.08 0.83
1-3Y -0.03 ± 0.07 -0.03 ± 0.07 0.87

7. 7
• Slight undercorrection in both
groups
• Thus, internal nomogram
used for compensation of
undercorrection:
• Resulting SE-deviation from
emmetropia:
Results: Predictability of Spherical Equivalent (SE)
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RULE:
If myopia ≤-3,0D
then increase Traget
SE correction by
approx. 10%
PTA<40% PTA≥40%
SE
[D]
mean
± stdv
mean
± stdv
p-value
1M 0.00 ± 0.31 -0.15 ± 0.41 <0.001
3M 0.01 ± 0.30 -0.24 ± 0.48 <0.001
6M -0.07 ± 0.32 -0.23 ± 0.52 0.03
1-3> 0.04 ± 0.39 -0.26 ± 0.46 <0.001
• Eyes with high PTA display slighly but significantly bigger
variance and undercorrection of approx. -0.25D

8. • Besides 1 month after SMILE:
PTA<40% group postoperatively
with slighty (~2 letters) but
significantly better UDVA
• Efficacy: Consider difference
UDVA(post) – CDVA(pre)
• No significant differences in terms of
efficacy
-0.2
-0.1
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
1.1
1.2
1.3
1.4
1.5
pre 1M 3M 6M 1-3Y
monocularUDVA[logMAR]
Visual recovery
Results: Visual Recovery & Efficacy
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• Similar results for both groups
• Differences in postoperative UDVA presumably due to differences in preoperative CDVA
and higher undercorrection in PTA≥40% group.
PTA
Number of eyes
pre 1M 3M 6M 1-3Y
<40% 291 222 74 70 86
≥40% 363 264 82 65 85
PTA<40% PTA≥40%
UDVA(post)
- CDVA(pre)
[logMAR]
mean
± stdv
mean
± stdv
p-value
1M 0.04 ± 0.11 0.04 ± 0.11 0.93
3M 0.02 ± 0.10 0.05 ± 0.13 0.13
6M 0.02 ± 0.09 0.05 ± 0.13 0.19
1-3Y 0.00 ± 0.09 0.03 ± 0.12 0.12
-0.03 ± 0.10
0.01 ± 0.12

9. -2
-1.5
-1
-0.5
0
0.5
1
1.5
Astigmatism Total HOA Coma Spherical
Aberration
Aberrationens(RMS)[µm]
Corneal Aberrations (6mm)
pre (n=289)
1-3Y (n=56)
pre (n=281)
1-3Y (n=54)
9
Significant (p<0.05) differences:
• Higher preoperative astigmatism in high PTA group
• In both groups: astigmatism reduced, aberrations increased
• Higher postoperative spherical aberration for group with high PTA values
≠
≠
Results: Wavefront Analysis
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PTA<40%
PTA≥40%
RMS = root mean square
n = number of eyes

10. Scheimpflug Tomography (Pentacam):
Belin-Ambrósio Enhanced Ecatsia Display
• Method fits spheres to:
1. Corneal surface and
2. Corneal surface with 4mm-zone
(centred on the thinnest point)
excluded
• Difference of both spheres reveals
possible ectatic defomations
• Can be applied to both anterior
and posterior corneal surface
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Example:
Keratoconus grade I-II

11. 0%
25%
50%
75%
100%
(-oo , 5.0) [5.0 , 7.0] (7.0 , oo)
PercentageofEyes[%]
EDM(Anterior) [µm] within interval
Extremum of the Difference-Map (Anterior)
pre (n=297)
1M (n=88)
3M (n=20)
6M (n=23)
1-3Y (n=44)
pre (n=352)
1M (n=135)
3M (n=35)
6M (n=40)
1-3Y (n=52)
0%
25%
50%
75%
100%
(-oo , 5.0) [5.0 , 7.0] (7.0 , oo)
PercentageofEyes[%]
EDM(Anterior) [µm] within interval
Extremum of the Difference-Map (Anterior)
pre (n=297)
1M (n=88)
3M (n=20)
6M (n=23)
1-3Y (n=44)
pre (n=352)
1M (n=135)
3M (n=35)
6M (n=40)
1-3Y (n=52)
Results: Belin-Ambrósio Enhanced Ectasia Display
Anterior Corneal Surface
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• Difference map values of anterior corneal surface reduced after SMILE treatment
• Postoperatively in both groups: No eye within critical range: EDM(Anterior) > 7.0µm
 No evidence for corneal steepening or development of keratectasia for high PTA
EDM = Extremum of the
difference map
n = number of eyes
PTA<40%PTA≥40%

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Conclusion and Outlook
Significant differences? PTA<40% PTA≥40%
Safety
CDVA(post) – CDVA(pre)
No
Predictabiliy
target vs. Achieved SE correction
Undercorrection of approx. -0.25D
and slightly bigger variance
Visual Recovery
UDVA at pre, 1M, 3M, 6M, 1-3Y
After 1M: UDVA slightly better
by about 2 letters
Efficacy
UDVA(post) – CDVA(pre)
No
Wavefront analysis
Corneal aberrations at 6mm
Astigmatism reduced and HOA aberrations induced by the same amount
Scheimpflug tomography:
Enhanced Ectasia Display
No eyes within critical range postoperatively
 No evidence for corneal steepening or development of keratectasia
Question: Increase PTA without inducing late keratectasia?
 Much more data as well as longer follow-up period needed

13. 13© by Premium Eyes Laser Eye Surgery · premiumeyes.de · · Slide17-06-04
Outlook

14. Thank you very much for your attention!