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Issues to cover:

Issues to cover:. Spherical vs. Aspherical Effect of Pupil Size Effect of IOL decentration Surgeon’s perspective. Spherical vs. Aspherical. SPHERICAL. ASPHERIC. Peripheral light rays are defocused. How does it affect the image?. SPHERICAL ASPHERIC. High-end cameras

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Issues to cover:

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  1. Issues to cover: • Spherical vs. Aspherical • Effect of Pupil Size • Effect of IOL decentration • Surgeon’s perspective

  2. Spherical vs. Aspherical

  3. SPHERICAL ASPHERIC Peripheral light rays are defocused.

  4. How does it affect the image? SPHERICAL ASPHERIC

  5. High-end cameras use aspheric lenses…

  6. Ophthalmologists and Optometrists currently use aspheric lenses every day…

  7. Contrast Sensitivity High-------------Contrast-------------Low Low ----------------Spatial Frequency---------------High

  8. Contrast Sensitivity: Normal

  9. Contrast Sensitivity: minus 25%

  10. Contrast Sensitivity: minus 50%

  11. Contrast Sensitivity: minus 75%

  12. Real world IOL results • 25% reduction in contrast sensitivity with a spheric IOL vs. aspheric IOL Spheric IOL Aspheric IOL

  13. Effect of Pupil Size

  14. Pupil Size With small pupils and good lighting, the aspheric IOL and the spheric IOL perform similarly because… Small Pupils BLOCK the peripheral rays.

  15. Effect of Pupil Size

  16. Effect of Pupil Size With Small Pupils the Images are the same

  17. Effect of Pupil Size With Large Pupils the Images are different

  18. The BEST image possible:Small Pupil / Bright Sunlight Aspheric IOL is EQUAL to the regular IOL.

  19. The WORST image possible:Large Pupil / Dim Lighting Aspheric IOL is BETTER than the regular IOL.

  20. Effect of IOL decentration

  21. Effect of IOL decentration With decentered IOLs, the Aspheric IOL will outperform all spherical IOLs

  22. How common is IOL decentration? • 33% of 3-pc IOLs decenter by > 0.5 mm • Average decentration of 1.12 mm • Hwang IP, Clinch TE, Moshifar M, Malmquist L, Cason M, Crandall AS • J Cataract Refract Surg. 1998 Nov;24(11):1505-8.

  23. What causes IOL decentration? • #1 The normal contraction of the capsule. • #2 Irregular capsulorhexis. • #3 One haptic in the bag, one outside.

  24. Benefits of the AO IOL: • Aspheric Optics • Less aberrations • Increased contrast sensitivity • Not as affected by decentration • Better image quality Drawbacks of this IOL: • Increased Cost of IOL • Our patients deserve the best

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