Multifocal Intraocular Lenses & Contrast

Sensitivity

Dr Kerrie MeadesMBBS(Hons) FRANZCO FRACS

Cataract and Refractive Surgeon

Multifocal IOL’s

Come in three basic types;

RefractiveDiffractiveAccommodative

Multifocal IOL’s can also be Aspheric & contain a UV or blue filter

Aspheric IOL’sThe 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

Filters – Blue light & UV

The human lens has the ability to filter UV and blue light naturallyBlue light filtration (yellow) & UV blocking is believed to slow down the progression of AMD caused by exposurevirtually 100% of IOL's now contain UV-absorbers

Multifocal IOL’s

Multifocal IOL’s 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 IOL’s to suit a patients visual requirements.

RefractiveRefractive multifocal IOL’s

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

DiffractiveDiffractive multifocal IOL’s

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

Restor

Tecnis

AccommodativeAn accommodative IOL only has

one focal point, but the focal point movesThe IOL has a hinge similar to the

mechanics of the eye’s natural lens.Using the eye’s muscles, the

single focal point of an accommodative IOL can shift to bring objects at varying distances into focusPatients get good DVA but NVA

may be variable No Haloing

Tetraflex

crystalens 5-0

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 IOL’s implanted Sept 2008

Patients vision 6/6, N5 each eye

Patient very happy with vision and overall performance of IOL especially at intermediate distances

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.

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.

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),

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.

AcrySof® ReSTOR® IOL

Binocular Mesopic Contrast SensitivityClinical Significance 0.3 log units at 2 or more

Spatial Frequencies

0

0.3

0.6

0.9

1.2

1.5

1.8

2.1

3 cpd 6 cpd 12 cpd 18 cpd

Mea

n C

ontr

ast Sen

siti

vity

(l

og u

nit

s +

/- S

D)

US ReSTOR - No Glare

US Control - No Glare

US ReSTOR - With Glare

US Control - With Glare

AcrySof® ReSTOR® IOL

Binocular Photopic Contrast Sensitivity

Clinical Significance 0.3 log units at 2 or more Spatial Frequencies

0

0.3

0.6

0.9

1.2

1.5

1.8

2.1

3 cpd 6 cpd 12 cpd 18 cpd

Mean C

ontr

ast

Sensi

tivit

y

(log u

nit

s +

/-

SD

)

US ReSTOR - No Glare

US Control - No Glare

US ReSTOR - With Glare

US Control - With Glare

Largest difference =0.20 log units

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

AcrySof® ReSTOR® IOL

Monocular Contrast Sensitivity Mesopic Conditions - With Glare

0

0.3

0.6

0.9

1.2

1.5

1.8

2.1

2.4

3 cpd 6 cpd 12 cpd 18 cpd

Cont

rast

Sen

siti

vity

(lo

g un

its)

Monofocal ReSTOR

Clinical Significance 0.3 log units at 2 or more Spatial Frequencies

AcrySof® ReSTOR® IOL

Monocular Contrast Sensitivity Photopic Conditions - No Glare

0

0.3

0.6

0.9

1.2

1.5

1.8

2.1

2.4

3 cpd 6 cpd 12 cpd 18 cpd

Con

tras

t Se

nsit

ivit

y (l

og u

nits

)

Monofocal ReSTOR

Clinical Significance 0.3 log units at 2 or more Spatial Frequencies

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.

Thank you