Peripheral optimized CXL and high power Theo Seiler

  • Slides: 16
Download presentation
Peripheral optimized CXL and high power Theo Seiler Institut für Refraktive und Ophthalmo-Chirurgie (IROC

Peripheral optimized CXL and high power Theo Seiler Institut für Refraktive und Ophthalmo-Chirurgie (IROC ) and University of Zürich Seite 1

PMD thinnest point steepest point Seite 2

PMD thinnest point steepest point Seite 2

PMD vs KC PMD thinnest pachymetry / μm KC 700 500 300 Seite 3

PMD vs KC PMD thinnest pachymetry / μm KC 700 500 300 Seite 3 0 0. 5 1 radial distance to apex / mm 2

PMD Seite 4

PMD Seite 4

PMD Seite 5

PMD Seite 5

CXL In the majority of the keratectasia cases the weakest point of the cornea

CXL In the majority of the keratectasia cases the weakest point of the cornea that needs CXL most is 1 to 3 mm away from the center Seite 6

study OCT 1 month post CXL, 10 eyes, inhomogeneity of the beam in curve

study OCT 1 month post CXL, 10 eyes, inhomogeneity of the beam in curve th 1 relative depth in % 100 90 th 80 th 1 70 mav 60 50 0 Seite 7 0 1 2 radial distance / mm 3

proposal In order to create a homogeneous CXL-effect also in the periphery of the

proposal In order to create a homogeneous CXL-effect also in the periphery of the cornea irradiation with a top hat-profile is not good enough. 3 mm away from the center the light intensity needs to be increased by at least 25% Seite 8

profile UV-X 2000 Avedro I 0 UV-X 1000 8 mm Seite 9 4 mm

profile UV-X 2000 Avedro I 0 UV-X 1000 8 mm Seite 9 4 mm 0 4 mm 8 mm

profile Crosslinking profile of the UV-X 2000 Seite 10

profile Crosslinking profile of the UV-X 2000 Seite 10

CXL-types volume-type 0μm 30 min 3. 00 m. W/cm² surface-type 9 min 10. 00

CXL-types volume-type 0μm 30 min 3. 00 m. W/cm² surface-type 9 min 10. 00 m. W/cm² 100μm 200μm 300μm 400μm 500μm 600μm Seite 11 0. 1% 0. 5% 30 min 2 min

CXL-types Pseudo-Bowmans Seite 12

CXL-types Pseudo-Bowmans Seite 12

CXL-types Seite 13

CXL-types Seite 13

CXL-types volume-type CXL-depth 250 to 330 μm Seite 14

CXL-types volume-type CXL-depth 250 to 330 μm Seite 14

CXL-types Applications volume-type (homogeneous riboflavin, low power) • infectious keratitis • melting diseases •

CXL-types Applications volume-type (homogeneous riboflavin, low power) • infectious keratitis • melting diseases • keratoconus ? Applications surface-type riboflavin gradient, high power) • refractive laser surgery • customized CXL Seite 15 (high

conclusion 1. In the majority of the cases a peripheral CXL is mandatory 2.

conclusion 1. In the majority of the cases a peripheral CXL is mandatory 2. Second generation CXL lightsources need an optimized beam profile 3. The surface-type CXL works only if the central irradiance guarantees an illumination time of 10 min and less Seite 16