Comparison of MTF Performance of Apodized Diffractive Multiofocal

and Sector-Based IOLs

Jim Schwiegerling, PhDUniversity of Arizona

Optical Sciences

Ophthalmology & Vision Sciences

Warren Hill, MD, FACSEast Valley Ophthalmology

5620 E. Broadway Road

Mesa, AZ 85206

Disclosure: Hill: Consultant, Speaker & Research Support Alcon ResearchSchwiegerling: Research & Travel support from Alcon Research.

Introduction

The optical performance of +3D-Add aspheric apodized diffractive multifocal IOL is compared to +1.50D-Add and +3.00D-Add with sector-based bifocal IOL lens designs.

• The diffractive multifocal lens is a +21D ReSTOR SN6AD1 (Alcon Laboratories).

• The sector based IOLs are a +30D Lentis Mplus LS-312 MF 15 and a +25D Lentis Mplus LS-312 MF 30

Measuring MTF• The IOL is placed in a wet cell mounted behind an artificial cornea.

• The blurred image of a slit target is analyzed to determine the Modulation Transfer Function (MTF).

• The slit is moved axially to measure MTF for different object distances.

Lens DesignsThe apodized diffractive has a roughly 3mm multifocal diffractive zone in the center of the lens. The sector-based lens has a nearly 180 degree sector in the inferior portion of the lens with increased power.

Slit Images• The following slide shows the raw slit images from our MTF testing system.• The grayscale has been inverted to highlight the effects of simultaneous

vision on the image.• All images are taken under the same conditions. No additional adjustments

to contrast or brightness have been done.• The near foci are taken as the highest contrast image in the near vision

portion of the through focus measurement. The labeled value of the near foci is relative to the spectacle plane.

• The apodized diffractive lens is specified as a +3D-Add at the IOL plane, which is equivalent to roughly a +2D-Add in the spectacle plane when vertex adjusted.

• The sector-based lenses are specified as +3D-Add and +1.50-Add. The values are already in the spectacle plane.

Slit ImagesDistance Foci

Near Foci (Spectacle Plane)

Apodized diffractive +30D Sector-based+25D Sector-based

+2D-Add +3D-Add +1.25D-Add

MTF

Spatial Frequency = 50 cyc/mm and a 6 mm pupil.

Conclusion• The MTF of the apodized diffractive had superior contrast

for the distance foci.

• For a 6 mm pupil, the apodized diffractive suppresses the performance of its near foci, but even under these consitions, the contrast was higher than the near foci of the +3D-Add sector-based lens.

• The labeled add power for the apodized diffractive lens is in the IOL plane and must be vertex adjusted to the spectacle plane. The labeled add power for the sector-based lens is relative to the spectacle plane.