IOL SelectionWhat to Ask and What to Tell
Dr. Inderjit Singh FRCS(London),FRCOPTH ,FRANZCO
Chatswood Eye Centre
Suite 5, 16-18 Malvern Av, Chatswood
Tel 94114877
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IOL what to askWhat is your Ultimate Goal
• 72yr old very fit lady with visually significant cataracts – surgery discussed, straight forward consult for cataract surgery and IOL to improve visual function
• but pt also mentions that she travels frequently,• And her next trip =
CATARACT SURGERY- THE CONVERGENCE
• The pt’s visual goal• The surgeon’s expertise with technique and use
of IOLS – need a variety of IOLs, one fits all not possible;
• Predictable results = <2.2mm astigmatic neutral incision; consistent round central capsulorhexis for consistent central IOL position
• The technology – improvements of IOL design. Better understanding of visual optics
The Best IOL choice for outcomes and pt satisfaction
Visual quality- all about vision with good contrast Pts expectations and pt selection (co morbidities) Pts visual needs IOL technology that can deliver above – keep up with IOL technology Surgeons experience with IOL technology Pt selection - every pt is different – not a cookie cutter answer; pts
near and intermediate va can differ - mobile phone, book, computer screen,dashboard
Neural adaptation - visual cortex has to adapt to multifocal IOLs or monovision
Binocular summation- 2 eyes with good distance vision have 40% better binocular contrast sesitivity compared to monocular vision
Choosing an IOL what to ask
• Mary 72 yr- needle work without glasses,happy to wear glasses for distance
• Fred 69yr-car enthusiast loves driving , wants to see as well as possible at night
• Jack 55yr- keen golfer/ surfer- wants distance and some near vision, glasses for reading
• Esther 68yr- traveller camper hiker near and distance vision without glasses
AGEING EYES, CHANGING VISIONAGEING EYES, CHANGING VISION
Increased ocular densitiesBlue end of visible spectrum filtered outOlder lens absorbs 1000x>at 400nm Increased higher order aberrationsScatter due to cataract formation causing glare
disability (? MVA)Decreased cone sensitivity-25% for each decade
starting at adolescenceNeural losses
The Ageing Eye For Glasses free high quality vision vision = Removal
of cataract +correction of aberrations of the eye
• Lower order aberrations • Higher order aberrations
Distortion of wavefront of light when it passes through eye with irregularities of its refractive components-tear film,cornea,lens
Visual Function Test- VF7Visual Function Test- VF7
•Reading signs – traffic,street,store•Seeing steps,stairs,or curbs•Watching TV•Night driving•Reading small print•Doing fine handiwork•Cooking
Lower order aberrationshave familiar names
• Myopia Astigmatism-87%ofcat pt• 33•
Hypermetropia
Proper technique has advantages over Femtosec laser assisted cataract surgery
Correction of lower order aberrations
Higher Order Aberrationsspherical Aberration is the most prevalent HOA in humans
•Higher-order aberrations comprise many varieties of aberrations. Some of them have names such as coma, trefoil and spherical aberration, but many more of them are identified only by mathematical expressions (Zernike polynomials). They make up about 15 percent of the total number of aberrations in an eye.•Order refers to the complexity of the shape of the wavefront emerging through the pupil — the more complex the shape, the higher the order of aberration.
Light ScatterLight ScatterEarlier Cataract Operations(4) Earlier Cataract Operations(4) There are two kinds of light—the glow that There are two kinds of light—the glow that
illuminates and the glare that obscures. illuminates and the glare that obscures. James ThurberJames Thurber
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The ageing eye- spherical aberration
Increased higher order aberrations-
mainly 3rd – coma4th order- spherical
aberrationIf an aberration
can be measured it can be corrected
Positive spherical aberration is produced when peripheral rays deviate and cross in front of the retinal plane.
Wavefront Aberrometer
Spherical aberration with ageas lens ages its positive aberration increases and total optical
system aberration increases ; contrast decreases;PUPIL DEPENDENT the fix = use aspherical IOL
The crystalline lens before age 20 (in blue) generates little SA due to a flat anterior surface and thin optic. Beyond age 20 (in red), the anterior surface becomes more spherical (oblate) and induces increasing amounts of SA
• Using aspheric IOL improves driving particularly evident on nighttime simulation testing, in which up to a 45-foot advantage in stopping distance at 55 mph (88.51 km/hr) can be achieved.
Different IOLs can be used to offset different amounts of spherical aberration
Refractive cataract surgery
1.Restore transparency of ocular media i.e remove opaque lens
2.Accurately correct any refractive aberrations of the eye - myopia,hyperopia
3.Correct astigmatism4.Reduce spec dependence5. 1+2+3+4 = predictable stable visual outcome6.WHAT ABOUT NEAR VISION
MULTIFOCAL IOLsrefractive,diffractive,bifocal optics
What To TellMultifocal IOLs – we have the technology to
somewhat turn the clock back !
Spectacle free distance and near vision•94% spectacles free (3 mnths)•6% used glasses for specific dim light tasks•8% c/o visual disturbances in the 1st week.•40% noticed some visual symptoms when asked – not intolerable•None of the symptoms were severe enough to explant IOL•All of pts would recommend IOL
WHAT TO TELL – more important to tellTHE DISADVANTAGES OF MULTIFOCALS
• All MF have some optical disadvantages• Light entering the eye through a MF is split into
more then one focal point• Halos , glare, decreased contrast sensitivity at
night,negative and positive dysphotopsia• MF not suitable for night drivers• Pt with any other ocular comorbidities will notice
these more readily – dry eye,AMD• Intermediate distance va (computer) poor
What To TellThe New Multifocal Family- “Multifocal Light”
for the active elderly
• Good distance va• Less halos,glare• Contrast sensitivity
effected less• Intermediate distance
va better• Still have acceptable
near va• But need glasses for
reading fine print
• Oculentis comfort ReStore +2.5
• Zeiss Lisa Trifocal
Multifocal “Light”Refractive Diffractive( ReStor +2.5) ;
Bifocal (Oculentis Comfort)• 50 pts=57-87yrs(65-87)• All wanted to spectacle free for distance ,driving,golf,sailing,touring• Wanted some reading vision (computer work) , willing to wear glasses for
fine print reading
• UCDVA= 6/9-6/4(94%6/6 or better)• UCNVA= N8-N5 (44%N8)• All were Toric IOLs except 8 eyes• 10% noticed visual disturbance in 1st week• 6% noticed halos,glare (at night) but not intolerable• No explants
What To Tell – Contraindications of Multifocal IOL s
Ocular Co Morbidities
• Dry eye condition• AMD- wet or dry or pre AMD (drusen)• Diabetic macular oedema and retinopathy• Irregular astigmatism• Previous corneal surgery (Lasik)
ACRYSOF ReSTOR +2.5
• 50 pts=57-87yrs(65-87)• All wanted to spectacle free for distance ,driving,golf,sailing,touring• Wanted some reading vision (computer work) , willing to wear glasses for
fine print reading
• UCDVA= 6/9-6/4(94%6/6 or better)• UCNVA= N8-N5 (44%N8)• All were Toric IOLs except 2 eyes• 10% noticed visual disturbance in 1st week• 8% noticed halos,glare (at night) but not intolerable• No explants
Continual quest for high quality correction
Ophthalmologists and their patients are continually striving for high quality vision correction. Perhaps the television industry and Apple has set the bar even higher with the successful introduction of HDTV and retinal image IPad, which has verified patients’ (and their visual cortex’s) strong desire for a level of correction beyond lower order sphere and cylinder. This patient desire along with the increasing role of wavefront science in vision and eye care have produced a growing understanding and clinical awareness of the role of HOAs, specifically fourth order SA and its relationship to the pupil.SA is the most prevalent HOA in human vision and thus must be addressed in any efforts toward high quality vision correction. Its objective magnitude and subjective effects on vision are directly related to pupil diameter and, thus, that relationship must be addressed in the measurement and correction of SA. While such measurements have been effectively achieved and will continue to advance through the ever increasing sophistication of wavefront aberrometry, the correction of SA and its relationship to the pupil will present unique challenges, some of which have already been addressed with developing
Continual Quest for high quality vision by Ophthalomolgist and the patient
• Perphaps introduction of HDTV ,iPad with retina display are setting the bar even higher for vision correction
• This has verified pts (and their visual cortex) strong desire for correction beyond lower order sphere and cylinder
• Increasing role of wavefront science in identifying HOAs that can be corrected (SA) to achieve high quality vision.
• This playing increasing part in IOL design and use
Cataract Surgery With Implantation of an Artificial LensThomas Kohnen, Prof. Dr. med.,1,2,* Martin Baumeister, Dr. med.,1 Daniel Kook, Dr. med.,3 Oliver K. Klaproth, Dipl.-Ing. (FH),1 and Christian Ohrloff,
Prof. Dr. med.
• The main criterion for the success of cataract surgery, aside for an uncomplicated course of the procedure itself, is the long-term visual result. The most commonly evaluated endpoints are high-contrast visual acuity and the residual refraction deficit at the visual distances for which the implanted lens is intended (6, 21). The expression “quality of vision” has been coined in view of the fact that high-contrast visual acuity, though it can be measured simply and quickly, is not a fully adequate measure of the complex phenomenon of visual perception (e33, e34). Quality of vision is the patient’s ability to see well in the context of his or her own individual visual requirements (e35). Various objective and subjective measures are used to determine the quality of vision (6, 22).