seite 1 peripheral optimized cxl and high power peripheral optimized cxl and high power theo seiler...
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Seite 1
Peripheral optimized CXL and high power Peripheral optimized CXL and high power
Theo SeilerTheo Seiler
IInstitut für nstitut für RRefraktive und efraktive und OOphthalmo-phthalmo-CChirurgie hirurgie (IROC )(IROC )andand
University of ZürichUniversity of Zürich
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thinnest pointsteepest point
PMD PMD
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0 0.5 1.51 2radial distance to apex /
mm
300
500
700
thinnest pachymetry / μm
PMD
KC
PMD vs KC PMD vs KC
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PMD PMD
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PMD PMD
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In the majority of the keratectasia casesIn the majority of the keratectasia cases
the weakest point of the cornea the weakest point of the cornea
that needs CXL most that needs CXL most
is 1 to 3 mm away from the centeris 1 to 3 mm away from the center
CXLCXL
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radial distance / mm
rela
tive d
ep
th
in %
0 1 2 3
50
60
70
80
90
100
0
th
th1
mav
studystudyOCT 1 month post CXL, 10 eyes, OCT 1 month post CXL, 10 eyes,
inhomogeneity of the beam in curve thinhomogeneity of the beam in curve th11
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In order to create a homogeneous CXL-effect also inIn order to create a homogeneous CXL-effect also in
the periphery of the corneathe periphery of the cornea
irradiation with a irradiation with a top hat-profile is not good top hat-profile is not good enough. enough.
3 mm away from the center the light intensity needs 3 mm away from the center the light intensity needs
to be increased to be increased by at least 25% by at least 25%
proposalproposal
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profileprofile
II00
UV-X1000UV-X1000
UV-X2000UV-X2000
AvedroAvedro
0 4mm
4mm
8mm
8mm
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profileprofile
Crosslinking profile of the UV-X2000Crosslinking profile of the UV-X2000
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CXL-types CXL-types
volume-type volume-type
0μm
100μm
200μm
300μm
400μm
500μm
600μm
30 min3.00 mW/cm²
9min10.00 mW/cm²
surface-type surface-type
0.1%0.1%
30 min 30 min
0.5%0.5%
2 min 2 min
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Pseudo-Bowmans Pseudo-Bowmans
CXL-types CXL-types
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CXL-types CXL-types
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CXL-types CXL-types
volume-typevolume-type
CXL-depth 250 to 330 CXL-depth 250 to 330 μμm m
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CXL-types CXL-types
Applications volume-type Applications volume-type (homogeneous riboflavin, low power)(homogeneous riboflavin, low power)
•infectious keratitisinfectious keratitis•melting diseasesmelting diseases•keratoconus ?keratoconus ?
Applications surface-type Applications surface-type (high riboflavin gradient, high power)(high riboflavin gradient, high power)
•refractive laser surgeryrefractive laser surgery•customized CXLcustomized CXL
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conclusionconclusion
1.1. In the majority of the cases a peripheral In the majority of the cases a peripheral CXL is mandatoryCXL is mandatory
2.2. Second generation CXL lightsources need Second generation CXL lightsources need an optimized beam profilean optimized beam profile
3.3. The surface-type CXL works only if the The surface-type CXL works only if the central irradiance guarantees an central irradiance guarantees an illumination time of 10 min and less illumination time of 10 min and less
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