1. ICT – Intraoperative Corneal Topography for image registration purposes S.Schründer

2. Model eye 6mm optical zone 8mm corneal radius 6mm pupil, 4mm below apex 5mm to rotation axis 12mm radius bulbus

3. Tilted eye

4. Motivation Aberrometer Ablation pattern Tilted eye 1st wrong pattern TreatmentDiagnosis Ablation pattern Tilted eye 2nd wrong pattern Eyetracker

5. Solution Registration in 3d space

6. Requirement 3d objects

9. Height map pre ablation* *Difference to 8.4mm sphere Range 100µm

10. Height map post ablation* *Difference to 8.7mm sphere Range 100µm

11. Fine registration: Iterative Closest Point Find corresponding 3d points (via Hough tables) Minimize their distance Distance Minimization: 1.Levenberg-Marquardt for fast convergence 2.Simmulated annealing to overcome local minima

12. Registration points area Detected flap edge

13. Difference map after registration 7.5mm circle Range 105µm

14. Line scans Dimensions in mm

15. 3d Flap thickness 9.5mm circle Range 290µm

16. Line scans Dimensions in mm

17. Next steps Rigid incorporation into a laser system Extended clinical trials Stand alone device

18. Centered cornea

19. 0.5mm lateral shift

20. Corresponding tilt 0.22mm decentration

21. Linear function* *8mm corneal radius, 4mm apex/pupil, 13mm apex/rotation axis

22. Andreas Dankert Hendrik Fuchs Saso Spasovski Coworkers at BioShape

23. Thank you. bioshape.com