Multifocal Intraocular Lenses

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Multifocal Intraocular Lenses Contrast
Sensitivity

• Dr Kerrie Meades
• MBBS(Hons) FRANZCO FRACS
• Cataract and Refractive Surgeon

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Multifocal IOLs

• Come in three basic types
• Refractive
• Diffractive
• Accommodative
• Multifocal IOLs can also be Aspheric contain a
  UV or blue filter

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Aspheric IOLs

• The idea of the aspheric IOL is to return the eye
  to that of youthful optics, The young eye has
  zero Spherical Aberration
• With age, Spherical Aberration increases reducing
  functional vision

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Filters Blue light UV

• The human lens has the ability to filter UV and
  blue light naturally
• Blue light filtration (yellow) UV blocking is
  believed to slow down the progression of AMD
  caused by exposure
• virtually 100 of IOL's now contain UV-absorbers

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Multifocal IOLs

• Multifocal IOLs provide greater spectacle
  independence to patients
• Careful patient counseling is needed to match a
  lens solution to the patients expectations.
• Sometimes you may need to Mix IOLs to suit a
  patients visual requirements.

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Refractive

• Refractive multifocal IOLs are designed with
  several optical zones on the IOL.
• These zones provide various focal points,
  allowing for an improvement in distance,
  intermediate, near vision
• Rezoom offers a good DVA. Mid-distance haloing is
  a side effect

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Diffractive
Restor

• Diffractive multifocal IOLs have gradual
  diffractive steps on the IOL implant that create
  a smooth transition between focal points.
• The IOL also bends incoming light to the multiple
  focal points to increase vision in various
  lighting situations.
• Haloing is a side effect

Tecnis
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Accommodative
Tetraflex

• An accommodative IOL only has one focal point,
  but the focal point moves
• The IOL has a hinge similar to the mechanics of
  the eyes natural lens.
• Using the eyes muscles, the single focal point
  of an accommodative IOL can shift to bring
  objects at varying distances into focus
• Patients get good DVA but NVA may be variable
• No Haloing

crystalens 5-0
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Patient Experiences with Restor 3

• JW 68years
• Pre-op RVA 6/12 LVA 6/6
• R 1.25/1.00x36 L 1.25/0.75X36
• Both IOLs implanted Sept 2008
• Patients vision 6/6, N5 each eye
• Patient very happy with vision and overall
  performance of IOL especially at intermediate
  distances

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Contrast Sensitivity

• Contrast sensitivity is the visual ability to see
  objects that may not be outlined clearly or that
  do not stand out from their background.
• The ability to see a shade of gray on a white
  background or to see white on a light gray
  background declines with age.

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People with Low Contrast Sensitivity can suffer
from the following

• Trouble seeing traffic lights or cars at night
• Not being able to see spots on clothes, counters,
  or dishes
• Not seeing whether a flame is burning on a stove
• Needing a great deal of light to read
• Experiencing tired eyes while watching
  television.

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Tecnis Multifocal IOL

• The diffractive Tecnis ZM900 multifocal
  intraocular lens (AMO) provides good near visual
  acuity good contrast sensitivity atall
  distances
• Patients receiving the Tecnis multifocal IOL had
  better near visual acuity and better contrast
  sensitivity at all distancescompared to
  implantation with the refractive ReZoom
  multifocal IOL (AMO),

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AcrySof ReSTOR IOL

• There is no clinical or functional significant
  difference between the contrast sensitivity of
  AcrySof ReSTOR and monofocal control subjects
  at lower spatial frequencies
• Lower spatial frequencies are important for
  vision related to everyday life skills, such as
  walking, driving and reading.

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AcrySof ReSTOR IOL Binocular Mesopic Contrast
Sensitivity

• Clinical Significance ? 0.3 log units at 2 or
  more Spatial Frequencies

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AcrySof ReSTOR IOL Binocular Photopic Contrast
Sensitivity

• Clinical Significance ? 0.3 log units at 2 or
  more Spatial Frequencies

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Contrast Sensitivity

• The following 2 slides clearly show very little
  difference between Contrast Sensivity in a
  Multifocal IOL vs a Monofocal IOL
• It is also clear that Contrast Sensitivity in
  photopic conditions varies only slightly to the
  Contrast Sensitivity obtained in mesopic
  conditions for either style of lens

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AcrySof ReSTOR IOL Monocular Contrast
Sensitivity Mesopic Conditions - With Glare
Clinical Significance ? 0.3 log units at 2 or
more Spatial Frequencies
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AcrySof ReSTOR IOL Monocular Contrast
Sensitivity Photopic Conditions - No Glare
Clinical Significance ? 0.3 log units at 2 or
more Spatial Frequencies
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Acri.LISA Multifocal

• Due to asymmetrical light distribution Acri.LISA
  IOLs achieve a high light yield.
• The optical performance under mesopic conditions
  differs only slightly from photopic conditions.
• The contrast sensitivity is improved to a level
  which is within the normal range for healthy
  phakic patients.

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Thank you