Wavefront by Method of Ray Tracing: Because the Eye is Not a Telescope Joe S. Wakil, M.D. Chairman, Tracey Technologies, LLC and EyeSys Vision, Inc. Speaker has a Financial Interest

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

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

The Eye is NOT a Telescope 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

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 -VISX license for Custom LASIK

Hartmann-Shack Wavefront Sensor H/S Photo of patient with tight eye lid courtesy David Williams

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

Data Sample Points Data Sample Points

Multiplying the Number of Sites

Higher Local Density of Sites

Overlay of Two Sets of Site Configuration

Ray Tracing Objective lens Input Beam Retina Eye optics Position sensitive detector

Ray Tracing Objective lens Retina Eye optics Position sensitive detector

Ray Tracing Objective lens Retina Eye optics Position sensitive detector

Ray Tracing Objective lens Retina Eye optics Position sensitive detector

Ray Tracing Objective lens Retina Eye optics Position sensitive detector

Ray Tracing Objective lens Retina Eye optics Position sensitive detector

Refractive Error Measurements Myopia Hyperopia

Retinal Spot Diagram/Point Spread Function

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

Tracey Analysis Conoid of Sturm Evaluation Contrast Sensitivity Data Depth of Field Analysis Individual Data Point PSF’s Zernike Calculations

Diagnostic Capabilities Determine Higher Order Aberrations True Point Spread Function Presentation Optical Media Opacity Mapping Integrated Corneal Topography

Validation Studies Three independent studies of Tracey vs. Manifest Refraction Koch et al - 58 eyes Slade et al - 42 eyes Schalhorn et al - 106 eyes Results Accuracy to manifest <0.12 D Reproducibility <0.12 D

Post LASIK

Post LASIK

Post LASIK

Keratoconus

Normal

Normal

Accommodating IOL Change due to Accommodation Near Fixation Far Fixation

Advantages of Ray Tracing Aberrometry Combined with Corneal Topography - iTrace Robust dynamic range to measure highly irregular eyes including immediately post-op Multi-Zone Refraction in seconds to measure variations in refraction from normal night myopes to post-op results saving chair time Able to separate Corneal from Lenticular (internal ocular) sources of aberrations with EyeSys Corneal Topography Improved Diagnostic Wavefront to help in patient selection including Custom LASIK and IOL procedures

Conclusion The Tracey iTrace brings a new standard of care in completely assessing vision in terms of quality of vision (aberrometry) and corneal topography to progress visual correction diagnosis and treatments to its ultimate goals.