Multifocal Intraocular Lenses & Contrast Sensitivity Dr Kerrie Meades MBBS(Hons) FRANZCO FRACS Cataract and Refractive Surgeon

Multifocal IOL’s Come in three basic types; Refractive Diffractive Accommodative Multifocal IOL’s can also be Aspheric & contain a UV or blue filter

Aspheric IOL’s 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

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

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.

Refractive Refractive 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

Diffractive Diffractive 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

Accommodative An accommodative IOL only has one focal point, but the focal point moves The 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 focus Patients get good DVA but NVA may be variable No Haloing Tetraflex crystalens 5-0

Patient Experiences with Restor +3 JW 68years Pre-op RVA 6/12LVA 6/6 R +1.25/+1.00x36L +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 at all distances Patients receiving the Tecnis multifocal IOL had better near visual acuity and better contrast sensitivity at all distances compared 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 Sensitivity Clinical Significance  0.3 log units at 2 or more Spatial Frequencies

AcrySof ® ReSTOR ® IOL Binocular Photopic Contrast Sensitivity Clinical Significance  0.3 log units at 2 or more Spatial Frequencies

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 Clinical Significance  0.3 log units at 2 or more Spatial Frequencies

AcrySof ® ReSTOR ® IOL Monocular Contrast Sensitivity Photopic Conditions - No Glare 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