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

2. Spherical vs. Aspherical

3. SPHERICAL ASPHERIC Peripheral light rays are defocused.

4. How does it affect the image? SPHERICALASPHERIC

5. High-end cameras use aspheric lenses…

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

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

9. Contrast Sensitivity: Normal

10. Contrast Sensitivity: minus 25%

11. Contrast Sensitivity: minus 50%

12. Contrast Sensitivity: minus 75%

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

14. Effect of Pupil Size

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

16. Effect of Pupil Size

17. With Small Pupils the Images are the same

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

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

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

21. Effect of IOL decentration

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

23. How common is IOL decentration? 33% of 3-pc IOLs decenter by > 0.5 mm 33% of 3-pc IOLs decenter by > 0.5 mm Average decentration of 1.12 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.

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

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