Upload
others
View
2
Download
0
Embed Size (px)
Citation preview
EFCLIN 2018
‘IOLs for Better or Worse’
Consultant :Santen/AVSAnewOptic IncOptical ExpressOcular Therapeutix
Previously :AlconNovartisB and LZeissOculentis
St Thomas’ Hospital 1871
1868
1946
‘Why don’t you put a new lens in the eye, Sir ? ’
The story of how the first IOL happened is well known
Ridley’s observation that Perspex did not cause a foreign body reaction
The first operation
The first IOL operation was a secondary implant
• Overlooked in the furore that followed
• Extremely fortuitous
• By 3 months the capsule would have thickened and supported the IOL leading to an anatomical success
Posterior Capsule Opacification
63.8%
In 1994 Alcon approached me to see if we could confirm the German observation -
we started a study of PCO in PMMA, Silicone and Acrysof IOLs
Silicone PMMA Acrysof
0
10
20
30
40
50
60
6m 1yr 2yr 3yr
PMMASiliconeAcrysof
Percentage PCO vs Time
P=0.0001
Hollick Ophthal 1998
Dr O Nishi showed that a square edge profile prevented PCO
O Nishi et al JCRS 1999
Bag collapses around
the IOL and the posterior edge
creates a pressure
barrier to LEC migration
AcrySof SN60 Hoya YA-60BB(now obsolete)
Single piece hydrophobic acrylic, 6mm optic
Both marketed as square edge IOLs
0
20
40
60
80
100
3m 6m 12m 18m 24m
AcrysofHoya
Area of PCO
Median%
PCO
**
**
*
* P= <0.5
Hancox JCRS 2008
59 24227 192
395 360
745 710
Hoya Acrysof
PCO• Not all ‘square edges’ are equal• Hydrophilic IOLs are not so good
19.9µ - bad9.3µ - good
Acrysof Hoya
Silicone IOLs
Bausch & Lomb Soflex SE Bausch & Lomb SofPort AO
8.3µ 7.6µ
Hydrophobic Acrylic IOLs
Alcon
AcrySof IQ
Alcon
AcrySof Natural
Alcon
AcrySof MA60AC
8.5µ 9.3µ 9.9µ
AMO
Sensar
AMO
Tecnis Z9000
AMO
Tecnis ZM9000
9.2µ 9.0µ8.3µ
Hydrophilic IOLs get more PCO
Hydrophilic Acrylic IOLs
Bausch & Lomb Akreos
15.9µ
LenstecTetraflex
23.1µ
Rayner Superflex
15.6µ
• Machined dehydrated• Tumble polished to remove burr• Edge profile lost
• Inter relationship between material and engineering
What is a ‘square edge’ ?What is the best edge profile ??
The Lens that failed
Dreadful PCO
…. re engineer for 1.8mm incisionImprove edge and PCO prevention
B and L MI60MICS IOL
Accuject 2.2
Viscoject 1.8
Viscoject
1.5mm Internal diameter
MI60
• Specific injection system
• Material : resist higher compression forces, controlled unfolding
• Design : perfect stability in the bag, prevent PCO, provide excellent optical properties
Challenges
• Same hydrophilic and hydrophobic polymers but more PMMA and less water
• This makes the polymer stiffer and more resistant to tearingAkreos IOL Material
Hydrophilic HEMA
Hydrophobic PMMA
Water
INCISE IOL Material
31
Material Solution .... new custom designed polymer
• Reduced water content compared 22% versus 26%
Tensile strength
-Extremely resistant material-Tear strength : +300%
-Allows strong compression forces-Avoid haptic break during injection
Akreos
Modulus (rigidity)
-Stiffer than Akreos even at body temperature (35°C)-More stable in the capsular bag-More stable if bag compression Akreos
Elongation
-Strongly improved compared to Akreos (+43%)-Allows injection through very small cartridges
Akreos
Sharpest 360° Barrier Edge• New sharp edge process on the 360° posterior barrier
16µm
Akreos1 5µm
5µm
INCISE2
“It has a much better profile than previous hydrophilic IOLsand has the best edge of any IOL we have ever imaged”*
Prof. David Spalton2
1. Nanavaty MA et al. J Cataract Refract Surg 2008;34:677–686.2. Imaging & Evaluation of 1.4 IOL St Thomas’ Hospital Anish Dhital, David Spalton, Jimmy Boyce.. 35
*As imaged by David Spalton
High incidence of decentration - haptics too thin ?? ---- abandoned
• Hydrophilic IOL calcification – a problem solved
• A lens that died
• A new EDOF concept
• Accommodation – a lens for the future
Santen ‘Easy Focus’ IOL
A new ‘EDOF’ IOL
Consultant to Santen AVS
Trifocals
Better near vision
EDOF
Less dysphotopsia
Design Concept of the xact Mono-EDoF ME4
Visual Range“Depth of Focus”
Mono-FocalIOL
Bifocal+4D
EDoF+1.5D
Trifocal
NearDistance
IntermediateDistance
FarDistance
Minimal optical side effects
Halo /Glare/ Double vision
Reduced Halo / Glare
Xact MonoEDoF
Applicable to wider range of
patients
Aim of the project
• Hydrophobic diffractive IOLwith 4 rings
Lens performance through
• optical bench testing, • real life simulation• clinical evaluation
To produce a novel and different EDOF IOL
Lens type Optics Example
Monofocal Refractive Santen Xact W-60R
EDoF Diffractive Tecnis SymfonyZeiss At Lara
Aberration based Sifi Miniwell
Diffractive Santen Xact Mono-EDoF ME4
IOLs tested
Optical Bench Testing
• Optical Test Equipment : Trioptics OptoSpheric bench
• Model Cornea Used : Corneas matched to IOL asphericity
• Pupil Sizes (at the IOL plane) : 3.0 mm & 4.5 mm
• 550nm wavelength per ISO requirement
• Spatial frequency measured at 15 (50 lp) and 30 cycles / degree (100 lp) per equivalent to 20/40 and 20/20 (per ISO requirement)
Through Focus MTF Curves
Santen Mono-EDoF IOL has a broad single peak
Other EDoF IOLs have a biphasic curve which are smoothed by white light and corneal aberrations
Optical Bench Testing
Through Focus Images : 3mm aperture with Corneal asphericity matched to IOL asphericity
Monofocal(W-60R)
Mono-EDoF
Symfony
Miniwell
AT LARA
-0.5D 0.0D 0.5D 1.0D 1.5D
• Mono-EDoF has crisp emmetropic focus
• Excellent image quality from distance to immediate focus
4.5 mm pupil
3.0 mm pupilAverage MTF at
100lp/mm (20/20) for 60-70
yrs old
Effect of pupil size on MTF
Impact of Tilt and Decentration on MTF at 4.5mm pupil
0.5mm decentration
5° TiltMono-EDoF performs as well as normal eyeand is relatively insensitive to decentration and tilt
Average MTF at 50 lp/mm (20/40) eyes between 60 and 70 years old
• Mono-EDoF has a significantly higher MTF than the average MTF of an age matched phakic eye
• Mono-EDoF has higher MTF than other EDoFIOLs
• Relatively resistant to decentration and tilt in comparison to competitor IOLs
Optical bench testing
Real Life Vision Simulation Testing
• 3 cameras mounted side by side on car dashboard looking at the same object
• Wet cell system with matching corneas
• Images recorded under identical camera settings
Polychromatic Images / Photopic Conditions
Monofocal Mono-EDoF Tecnis Symfony
Distance
Decentered by 0.5mm
Polychromatic Images with Decentration / Mesopic Conditions
Monofocal Mono-EDoF Tecnis Symfony
View of car headlights with IOL off-axis (decentered by 0.5mm)
HeadlightsOff
HeadlightsOn
Video recording of car headlights with model cornea
Monofocal Mono-EDoF Tecnis Symfony
Night time conditions – 4.5mm at the IOL plane
Clinical Testing
• Pilot study – Florian Kretz, Rheine, Germany
• Healthy, normal eyes except for cataract– Preoperative keratometric cylinder ≤ 1.0 D
• Three month data– 4 patients, 8 eyes
1.5 D
3 month post-op Defocus Curve: xact Mono-EDoF
~ 1.80 D
~ 1.5D of Depth of Focus Monocular testing
~ 1.8D of Depth of Focus Binocular testing
Photopic contrast sensitivity
4 patients, 8 eyes
3 month post-op
There is no statistically significant differences between contrast sensitivity measurements with and without glare
Mesopic Contrast sensitivity
VISUAL EFFECTS ASSESSMENT
There were no complaints of unwanted visual effects.
Conclusion
• Higher MTF values and continuous range of vision is expected to result in higher levels of patient satisfaction
• Only 4 rings --- Low incidence of dysphoticsymptoms
Conclusion• Constant improvement in IOLs
• No such thing as a perfect IOL