Multifocal IOL Basics - Medicontur Meeting/2017... · Neuroadaptation or IOL (design, material) The...
Transcript of Multifocal IOL Basics - Medicontur Meeting/2017... · Neuroadaptation or IOL (design, material) The...
Multifocal IOL Basics
REFRACTIVE DIFFRACTIVE
Concentric zones:
M-flex (Rayner)
Segmented:LENTIS Mplus (Oculentis)
Progressive:
677MY (Medicontur)
Bifocal: IQ AcrySof ReSTOR (Alcon)
Trifocal: FineVision (PhysIOL)
Extended Depth Of Focus (EDOF):Tecnis Symfony (AMO)
Types of Multifocal Designs
Success of Multifocal IOLs
IOL• Material
• Chromatic aberration
• Technology• Bifocal, trifocal, progressive• Customize..• Exact sizing/refraction
• Precision (halos, glares)
• Light utilisation (contrast)
• DESIGN - PCO protection
PATIENT SELECTION• Eye
• Anatomy (aberrations, astigmatism, kappa angle)
• Retina • Anatomy (esp. macula)
• the first place /neuro-receptor of receiving signals
• Pupil• Dynamic pupilometry
• Brain• Neuroadaptation?
• Cognitive function – cognitive tests?
(METROVISION)
Neuroadaptation?
Despite the fact that it is generally accepted that the brain plays a major role in visual performance with these more complex intraocular lenses, which is referred as neuroadaptation, there are no studies available evaluating cortical activity in the presence of multifocal lenses
Rosa AM, BioMed Res, 2013
Why does it seem that neuroadaptation differs in different IOLs?
Role of Retina in transferring the input
RETINA = 1st CONTACT - PHOTORECEPTORS
• Colour, depth, shape, motions = encoded by photoreceptors of few hundred microns of retinal thickness
• Incoming visual signals are processed by at least 80 neural cell populations and 20 separate channels within the retina
• Visual information leaves the retina through 20 different channels
• The cortex extracts the relevant information from the retinal input
• Visual input is initially encoded in the retina in two dimensions: light & intensity
Jonathan J Nassi & Edward M. Callaway:
Parallel Processing Strategies of the Primate Visual System;
Natur reviewes, Neuroscience
Success of MF –Neuroadaptation or IOL (design, material)
The better the transfer of information from the retinal photoreceptors through the ganglion cells to the brain –i.e. better output (less work for brain) – the better the
toleration of patients – quicker “ neuroadaptation”
OPTIC is CRUCIAL
= IOL
ZOOM ONDIFFRACTIVE OPTICAL PRINCIPLES
DIFRACTIVE OPTICAL PRINCIPLES
• Diffraction refers to various phenomena which occur when a wave encounters an obstacle.
• = bending of waves around small obstacles and the spreading out of waves past small openings
• As the waves spread out into each other, constructive and destructive interference occurs
Geometric and Diffractive Optics
A simple refractive lens can be described
mathematically with geometric optics.
The dimensions of an IOL is several orders of
magnitude higher than the light wavelength.
DIFFRACTION
IS NEGLIBLE
Due to the wave-like behaviour of the light, the more
precise mathematical description is given the
diffractive optics.
The diffraction can not negligible if in the presence of
small obstacles or slits in the light path.
Effect of Diffractive Elements
2nd
diffractive
order
1st
diffractive
order
0th
diffractive
order
The diffraction is increasing if the dimensions of the microstructure and
the light wavelength can be found in the same order of magnitude.
Theoretically, infinite
diffraction order is
generated.
The enhanced diffractive
orders can be chosen with
the microstructure design.
For example:
Enhanced 0th and 1st orders
provide a bifocal IOL.
Comparison of a Monofocal (Refractive) and a Multifocal (Diffractive) IOL
Monofocal (refractive) IOL Multifocal (diffractive) IOL
MTF through-focus performance: MTF through-focus performance:
Distance
vision
Near
vision
Distance
vision
Connection Between Diffractive Orders and Additional Dioptric Powers
1st diffractive order Padd
2nd diffractive order 2 × Padd
3rd diffractive order 3 × Padd
1.08 D
2.17 D
3.25 D
Padd is designed by the diffractive structure
. . . . . .
0th diffractive order 0 0 D0th order normally
provides the far vision
(„refractive” focal point)
EXAMPLE:
Basic Structure of a Diffractive IOL
DIFFRACTIVE ARRAY
MONOFOCAL / TORIC LENS
MULTIFOCAL /
MULTIFOCAL-TORIC LENS
+
=
Key Parameters for Diffractive Design
When dealing with a diffractive optic these must be considered:
The reference wavelength is 555 nm (green): the peak of photopic sensitivity of retinal cells
Reading (vision) distance is determined by the additional dioptric:
Reading (vision) distance(s) ~ addP
1
Additional dioptric power [D] Reading (vision) distance [cm]
1.75 80
2.17 60
3.50 40
Examples:
Diffractive Structure Characteristics
STEP HEIGHT determines
energy distributionbetween far and additional
focal points
Diffractive Structure Characteristics
STEP WIDTHdetermines
additional dioptric power(the higher the addition the more frequented the diffractive rings)
Trifocal Diffractive Structure Design(FineVision)
1st diffractive structure:
Padd = 3.50 D
2nd diffractive structure:
Padd = 1.75 D
0th order: FAR
1st order: NEAR (3.5 D)
2nd order: NOT USABLE (7.0 D)
0th order: FAR
1st order: INTERMEDIATE (1.75 D)
2nd order: NEAR (3.5 D)
+
=Superimposed structure:
2nd order of the 2nd diffractive structure coincides with the 1st
order of the 1st diffractive structure
International patent ID: WO2011092169(A1) (assignee: PhysIOL)
Quadrofocal Diffractive Structure Design(PanOptix)
Four consecutive diffractive orders:
0th 1st 2nd 3rd
Corresponding dioptric powers:
0 (far) +1.08 +2.17 +3.25
1st diffractive order (+1.08 D) is suppressed
US Patent ID: 9335564 B2 (assignee: Novartis AG)
Apodization of a Diffractive Structure
Before apodization Apodized structure
Apodization:
Decreasing steps height
from the centre to the
periphery
Effects of Apodization
• Pupil-dependent light intensity distribution between the far andadditional focal points.
• Reduced light losses.
• Additional focal point or points are suppressed at large aperturesto decrease risk of dysphotopic effects (for instance: halo).
Chromatic Aberration & DIFFRACTIVE OPTICs
An important issue with diffractive optics is chromatic aberration.
WHY?
Basics of Chromatic Aberration
Chromatic aberration is occured by the
wavelength dependence of the refractive indexDifferent wavelengths are
focused to different focal points
Chromatic
blur
Bi-Flex 677MY is made by
Benz 25, hydrophilic acrylic material
having low chromatic aberration
(ABBE NUMBER: 58)
Chromatic Aberration of a Diffractive IOLin the Human eye
Far focal point: The larger
wavelength, the lower dioptric
power due to the positive chromatic
aberration of the imaging ocular
tissues.
Additional focal point: Slight
chromatic shift due to the opposite
polychromatic characteristics of the
human cornea and the wavelength-
dependence of the near focus.
ZOOM ON…..
Bi-Flex M
• diffractive–refractive design concept to provide improved control energy distribution
• 7 diffractive discontinuities, or steps, that have been incorporated in the anterior surface of the acrylic optic to provide the diffractive added power
• apodized diffractive optic design
• apodization improves image quality by optimizing light energy delivered to the retina by distributing the appropriate amounts of light to near and distant focal points, regardless of lighting situation.
Anterior
Apodized
Optic
6 mm
Aspheric Optic
(neutral approach)
6 mm
Biconvex
Optic
13mm
Bi-Flex M Technology
Central 3.0 mm
apodized diffractive
structure
Step heights decrease
peripherally
from 2.2 – 1.4 microns
+3.5D at lens plane
equalling +2.7D at
spectacle plane
Outer refractive zone
Aspheric (neutral approach)
Examples for Diffractive Multifocal IOL
Alcon AcrySof IQ PanOptix (non-apodized trifocal; Padd = 2.17 / 3.25 D)
Alcon AcrySof IQ ReSTOR (apodized bifocal; Padd = 2.5 D; 3.0 D)
AMO Tecnis Symfony (non-apodized EDOF; Padd = 1.75 D)
PhysIOL FineVision (apodized trifocal; Padd = 1.75 / 3.50 D)
Zeiss AT LISA tri (non-apodized trifocal; Padd = 1.66 / 3.25 D)
Characteristics:
• Very good far vision
• Very good near vision
• Insufficient intermediate vision
• Dysphotopic effects (halo, glare) depends on the diameter of the diffractive optics
• Chromatic aberration depends on the Abbé-number (the higher the Abbé-number, thelower the chromatic aberration)
• 0th and 1st consecutive diffractive orders are used generally (reduced light loss)
Bifocal IOLs – Clinical Aspects
0
0,2
0,4
0,6
0,8
1
1,2
1,4
Characteristics:
• Compromised good far vision
• Compromised good near vision
• Sufficient intermediate vision
• Dysphotopic effects (halo, glare) depends on the diameter of the diffractive optics
• Chromatic aberration depends on the Abbé-number (the higher the Abbé-number, thelower the chromatic aberration)
• 0th and two consecutive diffractive orders are used generally (reduced light loss)
Trifocal IOLs – Clinical Aspects
ASSESSMENT OF OPTICAL QUALITY
• MTF means how faithfully the lens reproduces detail
from the object to the image produced by the lens.
Modulation Tranfer Function
Transmitted contrast 100%
Transmitted contrast 50%
Transmitted contrast 2%
MTF = 1
MTF = 0.5
MTF = 0.02
MTF through-focus Performance ofBi-Flex 677MY and FineVision
MTF means how faithfully the lens reproduces detail from
the object to the image produced by the lens
Measurements performed for a spatial frequency of 50 lp/mm
according to the related ISO standard
Progressive Apodized Diffractive (PAD) Structure on Bi-Flex 677MY
• Reduces light loss
• Reduced risk of dysphotopic effects
• Enhances depth of focus(PROGRESSIVE VISION within full accommodative range)
• Improves the distance vision at large pupil apertures
Progressive apodization:
Bi-Flex M - Progressive IOL
Normal diffractive array
The diffractive / progressive matrix increases the depth of field of the near vision distance vision. (b). The
curves overlap in defocus the intermediate vision zone with a defocus of 1.5 dpt (67cm).
distance near
Characteristics:
• Very good (not compromised) far vision
• Very good near vision
• Competitive intermediate vision with trifocal IOLs
• Low level of photopic phenomena thanks very high Abbe number (58)
of the material and precision of diffractive steps
• Quick neuroadaptation
Bi-Flex M: PAD
Progressive Apodized Diffractive (PAD) Structure on Bi-Flex 677MY
Bi-Flex 677MY Bifocal competitor
Sub-micrometer
manufacturing precision:
• reduced light loss
• less dysphotopic effects
ZOOM ON…..
Bi-Flex M
• diffractive–refractive design concept to provide improved control energy distribution
• 7 diffractive discontinuities, or steps, that have been incorporated in the anterior surface of the acrylic optic to provide the diffractive added power
• apodized diffractive optic design
• apodization improves image quality by optimizing light energy delivered to the retina by distributing the appropriate amounts of light to near and distant focal points, regardless of lighting situation.
Anterior
Apodized
Optic
6 mm
Aspheric Optic
(neutral approach)
6 mm
Biconvex
Optic
13mm
Bi-Flex M Technology
Central 3.0 mm
apodized diffractive
structure
Step heights decrease
peripherally
from 2.2 – 1.4 microns
+3.5D at lens plane
equalling +2.7D at
spectacle plane
Outer refractive zone
Aspheric (neutral approach)
• PCO is limiting factor of success of multifocal IOLs
• PCO rate finally makes a difference in outcomes and patient satisfaction
• PCO prevention is more important for patients receiving multifocal IOLs
because of their increasing visual demandsBi-Flex M
• r = 10microns
• Polish free technology
Bi-Flex M and PCO
A unique & patented design
With 180° total contact angle with capsular bag equator
Medicontur Bi-Flex Average contact angle: 88.8°
Competitor 1Average contact Angle: 69°
Experimental simulator with a diameter of 9 mm
Competitor 2 Average contact Angle: 64.4°
Natural Yellow Filter+
• for FILTERING AS MUCH AS NECESSARY
for PRESERVING AS MUCH AS POSSIBLE
Medicontur natural yellow filter protects the macula against the wavelengths comprised between 390nm and 460nmthus covering the whole most dangerous zone of « blue light » and maintaining scotopic vision (over 460nm)
Bi Flex M yellow filter
MEDICONTUR
Natural
Yellow filter
Simulation of vision without and with yellow filter+
IOL
With NON natural
Yellow filter
IOL
With NO
Yellow filter
WHAT ABOUT THE MAIN COMPETITORs ?
Examples
• Trifocal, non-apodized: AT LISA tri (Zeiss): +1.67D, +3.33D
• Apodized bifocal: ReSTOR (Alcon) +3.5D or +3.00D
• Apodized trifocal: FineVision (PhysIOL): +1.75D, +3.50D
• Quadrifocal, non-apodized: Panoptix (Alcon): +2.17D, +3.25D
ZOOM ON THE MOST IMPORTANT MARKET PLAYERS…
TRIFOCAL
AT LISA TRI & PHYSIOL
PanOptix
Symfony
Reading
Contrast sensitivity
Alcon material
problems
FAR & INTERMEDIATE
No near vision
Contrast sensitivity
TRIFOCAL PANOPTIC SYMFONY
0,00
0,50
1,00
1,50
+4,0 D +3,5 D +3,0 D +2,5 D +2,0 D +1,5 D +1,0 D +0,0 D -0,5 D -1,0 D -1,5 D -2,0 D -2,5 D -3,0 D -3,5 D
Defocus curve - 6M
677MY
Based on clinical observation – Bi Flex M shows clinically clear trifocal performance
ZOOM ON…..
CLINICAL FEEDBACKS
Clinical Studies at Glance
9 countries2 continents 14 surgeons
3 prospective
study3 „prospective“
study
Quick
evaluation
results
Review of the Co-operating surgeons and Number of Operated Patients / Eyes
STATECENTRUM /
SURGEON
No of
patients
No of
eyes
GERMANY
AK Bellevue 26 52
Prof Böhnke 12 15
Dr Dörner 7 14
Dr Kohm 6 12
HUNGARY
Prof Nagy 54 108
Dr Gyory 50 100
Dr Nagymihaly 63 126
CZECH REPUBLIC Prof Pasta 10 20
STATECENTRUM /
SURGEON
No of
Patients
No of
EYES
SWITZERLAND Dr Sutter 5 10
ISRAEL Prof Zadok 10 20
SPAIN Baviera Group 4 8
PHILIPPINES Dr Naval 16 31
FRANCE Dr Assouline 100 200
AUSTRIA Prof Grabner 10 20
BELGIUM Dr Van Acker 35 70
TOTAL No of patients 393
No of eyes 786
-
0,20
0,40
0,60
0,80
1,00
1,20
AK Bellevue Prof Böhnke Dr Dörner Dr Kohm Prof Pasta Dr Sutter* Dr Gyori prof Zadok*
VA BINOCULAR 6 months follow-up
far inter near
MEAN UnCorected VA
(180 eyes)
FAR INTERMEDIATE
(65 cm)
NEAR
6 months
Follow-up
MONOCULAR 0.86 0.75 0.82
BINOCULAR 0.97 0.83 0.86
RESULTS**: 180 EYES
• *Prof Zadok: A const has been not optimized yet during his evaluation
• *Dr Sutter (5 pat.) : 1 patient – SEQ = -1.0; 1 patient astisgm. 1.75 dpt
* * Exact values of results might change by adding new patients results from other centres.
Comparison of Defocus curves Bi-Flex M and AT Lisa tri 839 MP (Zeiss)*
(binocular, follow-up 6M)
*P. Mojžíš, P. Peňa-Garcia, I. Liehneova, P. Žiak, J. Alio: Outcomes of a new diffractive
trifocal intraocular lens. J Cataract Refract Surg; 40:60-69, 2014
AT LISA Tri
Bi-Flex M – much better near VA, widen defocus curve for distance vision
(in agreement with PAD technology), competitive intermediate vision
(does not drop under 0.1 LogMar) to the trifocal IOL (Pasta J et al: presented at congress CSRKCH, CZ and at ESCRS London 2014)
Dunai A, Kranitzki K, Juhasz E, Nagy Z.
ESCRS 2016
Bi-Flex M contra ReStor (Alcon)
Bi-Flex M – 1 year follow up (binocular)
ESCRS 2016
Courtesy dr. Gyori, HU)
Contrast Sensitivity
• Photopic
• Mesopic
• In backlight
Courtesy by Dr Gyory, HU
Contrast Sensitivity:Comparison of Bi-Flex 677MY and FineVision
0
1
2
3
4
5
6
7
8
3 cpd 6 cpd 9 cpd 18 cpd
Photopic conditions
0
1
2
3
4
5
6
7
8
3 cpd 6 cpd 9 cpd 18 cpd
Mesopic conditions
0
1
2
3
4
5
6
7
8
3 cpd 6 cpd 9 cpd 18 cpd
Scotopic conditions
Bi-Flex 677 MY (AVG)
PhysIOL FineVision (AVG)
Bi-Flex 677 MY (AVG)
PhysIOL FineVision (AVG)
Bi-Flex 677 MY (AVG)
PhysIOL FineVision (AVG)
Courtesy by Dr Gyory, HU
VFQ 25 - page 1
Visual Functioning Questionnaire (VFQ) No problem Mild Moderate Strong Bad N/A
50 patients / Score 1 2 3 4 5 6 How much difficulty do you have with each of the following
Please tick the number from 1 to 6
Glare/Flare (trouble seeing street signs due to bright light or oncoming headlight? 27 20 2 - - -Night vision
49 1 - - - -Colour perception (trouble recognizing specific colours) 50 - - - - -Halos(rings around lights) 20 28 1 - - -Depth perception (trouble lining things up, pouring liquids or going down stairs) 50 - - - - -Distorted near vision
(straight lines looked crooked close up)50 - - - - -
Distorted distance vision (straight lines looked crooked at distance) 50 - - - - -
Blurred near vision49 1 - - - -
Blurred far vision50 - - - - -
Double vision49 1/? - - - -
Courtesy dr. Gyori, HU)
VFQ 25 - page 2Visual Functioning Questionnaire (VFQ) Response
1 to 6-point scale
VISUAL LIFESTYLE ACTIVITIES score 1 2 3 4 5 6
How much difficulty do you have with each activity due to your vision (without glasses or contact
lenses)
Watching TV or movies 48 2 - - - -
Playing or working outside 50 - - - - -
Caring for/playing with children 50 - - - - -
Reading the time on at alarm clock 48 2 - - - -
Seeing clearly when you wake up 46 4 - - - -
Reading the time on at wall clock 50 - - - - -
Performing your job/hobbies 48 2 - - - -
Participating in sports/recreation 50 - - - - -
Participating in social events 50 - - - - -
Reading and near work activities 48 2 - - - -
Driving at night 30 18 2 - - -
Driving when it is raining
Using a computer48
46
2
2
-
2
-
-
-
-
-
-
Cooking 50 - - - - -
Shopping 50 - - - - --
Using a cell phone 48 2 - - - --
Shaving or putting on make up 48 2 - - - -
50 patients
Courtesy dr. Gyori, HU)
Success of Progressive Bi-Flex M:
• Material - very low chromatic aberration
• Precision• PAD
• Apodisation• Special aberration on apodisative steps
increased depth of focus
• 1 DIFFRACTIVE ARRAY combined with PAD technology which does not sacrifices the “MTF peak” for far and near vision thanks to all technical properties and technical developments – progressive lens
• Clinical performance of Bi-Flex M supported by clinicalstudies is TRIFOCAL
References
• product websites
• www.gatinel.com
• Cionni, RJ et al: Get to Know the Defocus Curve, CRST, Nov 2010
• www.trioptics.com