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Integration of Aberrometry and Topography with the i Trace System

Integration of Aberrometry and Topography with the i Trace System. July 2005 Joe S. Wakil, MD - Tracey Technologies, LLC EyeSys Vision, Inc. Founding Technology Developers:. Vasyl Molebny, DSc Kiev, Ukraine Ioannis Pallikaris, MD Crete, Greece Canadian & Swedish Governments.

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Integration of Aberrometry and Topography with the i Trace System

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  1. Integration of Aberrometry and Topography with thei Trace System July 2005 Joe S. Wakil, MD - Tracey Technologies, LLC EyeSys Vision, Inc.

  2. Founding Technology Developers: Vasyl Molebny, DSc Kiev, Ukraine Ioannis Pallikaris, MD Crete, Greece Canadian & Swedish Governments

  3. Why Aberroscopy? Current Laser Technology Permits One to Go Beyond Correction of Sphere and Astigmatism You Can Now Address Your Patient’s Quality of Vision High Order Aberrations Define Quality of Vision

  4. Why Ray Tracing?Because… the Eye is NOT a Telescope! Effects Refraction (ex. Night Myopia) Refraction is NOT a FIXED Number! Effects Refraction (Instrument Myopia) Effects Quality of Vision (Aberrations) Pupil Size: Accommodation: Tear Film: Where are the Sources of Aberrations? How do they change with Surgery? Astigmatism (Irreg.), Sph & other HOA Astigmatism, Coma & other HOA Cornea: Lens:

  5. EYE Off-Axis design No magnification Variable aperture Variable detector res. Accommodation Changing fixation Brain image processing Nature-made TELESCOPE On-Axis design High magnification Fixed aperture Constant detector res. No accommodation Fixed alignment Digital image processing Man-made The Eye is NOT a Telescope

  6. Significant Higher Order Aberrations Trefoil Coma Spherical Aberration

  7. Aberrometer/Wavefront Technologies • Hartmann-Shack Lenslet Array • Tscherning Aberrometer • Differential Skiascopy • Ray Tracing Features: -Rapid, point by point, IR measurement - no data confusion -Pupillometry with auto-tracking/capture -Programmable sampling (256 pts.) in any pupil up to 8mm -Open Field Fixation – avoid instrument myopia and measure Accommodation -Corneal Topography integration – able to measure Lens Aberrations

  8. Hartmann Shack

  9. Hartmann Shack

  10. Hartmann-ShackWavefront Sensor H/S Photo of patient with tight eye lid courtesy David Williams

  11. Tscherning

  12. Disadvantages of H-S and Tscherning • Measures All Points at Once - Data Confusion, Compromised Resolution • Limited Dynamic Range – Cannot Measure Highly Irregular Eyes • Highly Sensitive to Noise – Slow, Requires Multiple Scans • Expensive Components – High Cost to Purchase and Repair • H-S Measures Reverse Aberrations – Not Physiologic with Real Vision especially for High Orders in Accomodation • Tscherning Needs 2-D Imaging of Retina - Additional noise and errors

  13. Differential Skiascopy

  14. Disadvantages of Differential Skiascopy • Does NOT Measure Skew Aberrations – Inaccurate WaveFront especially for Trefoil, Quadrafoil, etc. • Measures Multiple Points at Once (slit) and only in Perpendicular Direction - Limited WF measurement (axial bias) • No Open Field Fixation – Problem of instrument myopia in young patients

  15. *Measuring Corneal Aberrationwithout Lens or Total Aberration is of Questionable Value Total Ocular Aberrations Internal Optics Aberrations Corneal Aberrations Total Ocular Aberrations

  16. The iTrace

  17. Principles of Tracey • Programmable thin beam ray tracing measuring forward aberrations of the eye • Rapid sequential measurement of data points over entire entrance pupil (<50ms) • Localization of each reflected retinal spot • Integration of individual retinal spots to form Point Spread Function (PSF) • Analysis of PSF for higher order aberrations and other data formats

  18. Programmable Data Sample Points

  19. Multiplying the Number of Sites

  20. Higher Local Density of Sites

  21. Overlay of Two Sets of Site Configuration

  22. Refractive Error Measurements Myopia Hyperopia

  23. Retinal Spot Diagram/Point Spread Function

  24. Retinal Spot Diagram 40 Refraction Map 30 20 Y, µm 10 0 -10 -20 -20 -10 0 10 20 X, µm Ablation Map Wavefront Map Data Displays

  25. Tracey’s Key Advantage: Rapid, point-by-point analysis of 256 data points avoids data confusion associated with simultaneous data measurements, therefore, all eyes (highly irregular) can be measured. All points in any pupil size (2-8mm) each with full dynamic range (+/- 15 D). NO COMPROMISES!

  26. Baylor Clinical Study (100 eyes)by Doug Koch, MD +7D -13D

  27. Validation Studies Three independent studies of Tracey vs. Manifest Refraction • Koch et al - 100 eyes • Slade et al - 42 eyes • Schalhorn et al - 106 eyes Results • Accuracy to manifest <0.12 D • Reproducibility <0.12 D

  28. The iTrace

  29. Normal Eye

  30. Irregular Eye

  31. UCVA vs BCVA

  32. Post LASIK

  33. Full Corneal Topography

  34. Full Corneal Topography

  35. Keratoconus

  36. Normal

  37. iTrace Measures Accommodation Mechanism

  38. Very Spherical Accommodation

  39. Variations inMapping AccommodativePower in the Natural Crystalline LensasMeasured byiTrace Horizontal Cyl Sphere Vertical Cyl Coma

  40. 73 Year Old Male Crystalens Accommodative Arching Overall Refraction change is 0.5D but Central Cylinder 2.5 D adds Depth of Field to Enhance Accommodative Effect

  41. MultiFocal IOL Analysis withiTrace • PSF Analysis • Modulation Transfer Function (MTF)obust Aberrometer • Pupil Dependent Analysis • Multi-Zone Refraction Analysis • Retinal Spot Diagram • Conoid of Sturm Dynamic Analysis • Complete Corneal Topography Analysis • Separates Corneal from Total Aberrations Resulting in Lenticular (internal ocular) Aberrations • Measures Accommodation

  42. Multifocal Acrylic IOL Alcon ReStor Lens

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