Analysis of accommdation problem brought on by presbyopia and solutions in intra-ocular lens technologies available or in development toward market

1. Challenges and New Technologies for
Accommodating Intra-Ocular Lenses
in Presbyopia
Alan N. Glazier, OD, FAAO
2013

2. Binocular Accommodation
• Six components of Accommodation
• Mechanics of Each Function Together to Provide Human
Physiologic Binocular Accommodation
• Four components recognized as vital
–
–
–
–
increased convexity of the lens
anterior movement of the lens
miosis of the pupil
convergence of the eyes
• Two additional components;
– pupillary compression
– Gestalt (the “brain factor”)
• No one component of accommodation can account for
binocular near vision/All six must function

3. Importance of Accommodative
Amplitude
•
•
•
Accommodative Amplitude – Latent and Manifest Ability of Ciliary Muscle to Exert
and Sustain Effort on Ocular Lens at the Spectacle Plane
“Pushing” does not equal “Sustaining”
Sheard’s Criterion – Standard for Determining
Sufficient Amplitude for Near Vision Sustenance;
–
•
•
One-Third to One-Half of the Accommodative Amplitude
Needs to be Left in Reserve in Order to Allow for Sustained
Near-Point Activity. (A patient able to achieve 2.5 D with an
accommodative IOL should only be able to sustain use of
perhaps 1.25 D freely - 2.5 D of accommodative amplitude
does not equate with a 2.5-D bifocal add but more like a
1.25-D bifocal Add)
Most Current Technologies Have Demonstrated
Abilities of Slightly More Than 1.75 Diopters of Add Max
Reading Comfortably at 33 cm Would Require 3 D of Power at Spectacle Plane (4.5
to 6 D of Accommodative Amplitude - Leaving 1/3 of Accommodation Left in
Reserve).

4. Hinged Accommodating IOLs

5. Tetraflex

6. Kellan Tetraflex IOL
• Small-Incision (2.5mm) Single-Optic
Accommodative IOL.
• Hydroxymethylmethacrylate
• Has a 5.75- millimeter equiconvex optic and a
square-edged design to inhibit posterior capsular
opacification
• Approved in Europe, Australia and the Middle
East since 2003
• U.S. Trials are Beginning, With About 50 lenses
Implanted to Date. On Sale in US

7. Crystalens (Bausch & Lomb)

8. Crystalens (Eyeonics)
• The Crystalens is a modified, hinged, plate-haptic
silicone lens with polyimide loops. The lens has a
high refractive index of 1.43 with a UV filter. The
length of the lens plate is 10.5 mm, with a total
IOL length of 11.5 mm. The lens optic is biconvex
with a diameter of 5 mm. The IOL offers near and
intermediate focal ranges by way of anterior
displacement of the lens optic due to fluctuating
pressures within the vitreous cavity as the ciliary
body contracts

9. Crystalens
• Extra Power Provided by the CrystaLens May Not be
Sufficient/May Still Require a Reading Add (Reading
Add Still Required in About ½ of Patients)
• Small Optic - Issue With Patients With Large
Pupils/Significant Pupillary Dilation in Dim Light More Prone to Edge Glare
• Mean Accommodative Amplitude 1.79 diopters (Dell,
Steven, MD) 96% percent of eyes had a change in
distance acuity of ? ±1.0 D

10. https://www.youtube.com/watch?v=a9qEeD6jRJ8

11. ICU Akkommodative
(Human Optics)

12. ICU Akkomodative
• Foldable, Single-Piece IOL with an Optic
Diameter of 5.5 mm and an Overall length of
9.8 mm.
• Hydrophilic Acrylic material with a refractive
index of 1.46.
• Biconvex, Square-Edged Optic and Four
Flexible Haptics that Bend When Constricted
in the Capsular Bag After Ciliary Body
Contraction.

13. ICU Akkomodative
• Accommodating Mechanism Can Play Role in Capsule Fibrosis,
Likely to Reduce Amplitude of Device as Patient Ages
• Clinical Studies Report That Accommodation Amplitudes, 6 Months
After the Operation, Mean Value Between 1.7 D and 1.9 D
• Approximately 1.80 D of Accommodation Occurs Per 1 mm of
Anterior Movement of the Lens Optic. (Langerbucher et al )
• Mean Accommodative Amplitude Produced 1.8D (Kuchle et al)

14. http://www.youtube.com/watch?v=TF-Yv8IQu0w

15. Fibrosis – The Curse for Hinged Accommodating
IOL’s
• Short and long term study results show that capsule bag reduces
accommodative powers of the eye through shrinkage and fibrotic
processes
• Often leads to IOL dislocation and explantation due to hinge optic
designs. (Binder et al., Obertshausen, Germany)
• If Lens Doesn’t Move as Expected it Results in Diminished
Accommodative Capacity or Myopia at Distance (Blur)
• Long-Term Stability of the Hinge and Accommodative Refractive
Effect are not Known
• Fibrosis Likely to Reduce Amplitude of Device Further as Patient
Ages

16. Other Challenges
• Increased Rate of CME Associated With
Sulcus-Bag Placement of Haptics.
• Effects of Vitrectomy on Accommodative
Performance of “Movable” IOL’s are
unknown.
• Lower Powers → Less Accommodation
• Capsular Contraction → Distortion and
Decentration
• Wound Leaks → Unexpected Myopia

17. Dual Optic

18. Sarfarazi Elliptical IOL (Bausch &Lomb)

19. Synchrony (AMO)

20. Synchrony
• Designed With an Anterior High-Plus-Powered
Lens and a Posterior Minus Lens
• Pseudophakic Accommodation Occurs When
Zonular Tension is Released During Ciliary
Body Contraction Resulting in a Compression
of the Optic and Spring Haptic.
• Currently in Clinical Studies in the U.S. and
Recently Received CE Mark in Europe

21. Synchrony Dual-Optic Accommodating IOL (Visiogen)
• Model Calculated Approximately 2.20 D of
Accommodation
• Amplitude Measured at +2.50
(Burkhardt Dick, Cataract and Ref. Surgery, July 2004)
• Mean Accommodative Amplitude 2.55 D
( study by Ossma-Gomez, Ivan MD)
• Mean Monocular Amplitude of
Accommodation : 3.17D

22. https://www.youtube.com/watch?v=Qpldo0mfyqw

23. NuLens

25. NuLens
• Compressible Polymer Between Fixed Plates
On Accommodative Effort Polymer Bulges
Through Aperture in the Anterior Fixed Plate,
Resulting in an Increase in the Steepness of
the Anterior Surface.
• Still in Animal Studies

26. NuLens
• Progressive Capsular Contraction Following
Cataract Extraction With Subsequent IOL Power
Changes
• Difficult Distance (contracted ciliary body) IOL
Power Calculations
• Optical Aberrations From Peripheral Portions of
the IOL Not Undergoing Dynamic Power Changes
• Accommodation Not Governable
• Elderly Average Remaining Ciliary “Strength”
Insufficient to Take Advantage of Amazing
Accommodative Potential of Technology

27. SmartIOL

28. SmartIOL (Formerly SmartLens)
(Medennium)
• Hydrophobic Acrylic Made Into a Stable 2mm
Rod that can be inserted Into the Capsular Bag
and Forms a Full-Size Lens
• Optic-9.5 by 3.5-mm – Same as Human
Crystalline Lens

29. SmartIOL
• Difficult to Determine How Much Gel to Inject to
Predictably Control Resulting Lens Power.
• Capsulorhexis Must Be Small, So That It Can Be Sealed to
Confine the Gel. This May Require New Surgical
Technologies.
• Control Needed to Get the Critical Optical Interface in the
Central Location of the Capsulorhexis
• To Minimize Energy Consumption in Accommodation the
Intracapsular Pressure Built Up By Lens Epithelial Cells has
to be Restored By the Refill Procedure. Only Then Can the
Exchange of Potential Elastic Energy Between the Lens
Capsule and the Lens Matter Work. (Haefliger, E.,
Binningen, Switzerland)

30. The Fluid Lens (PowerVision)
• Redistributes Peripheral Fluid Centrally on
Accommodation Increasing the Plus Power of
the Optic

31. • Drives Fluid of a Polymer-Matched Refractive
Index From the IOLs Soft Haptics Thru
Channels to a Fluid-Driven Activator
• Causes an Accommodative Increase in the
Anterior Curvature of the Lens
• Curvature Change Has Been Shown to be As
High as 8D
• 6 Month Study on 30 Eyes Showed 5D Max

32. Quest Vision (AMO)
• Has Myopic Configuration in the Resting State
and an Anterior Position in the
Accommodative State

33. Electro-Active Accommodating IOL
(Elenza – Roanoke, VA)
• Switchable Liquid Crystal Diffractive Lens
• Electrical Control of the Refractive Index of a Nematic Liquid
Crystal Sandwiched Between A Photolithographically Defined
Transparent Electrode
• Hydrophobic IOL with Hermetically Sealed Circuitry
• Microsensors Detect Physiologic Changes in Light Triggered
by Accommodative Effort
• Lithium Ion Power Cells Charged Weekly by an Inductive
Charging Element

34. LiquiLens
Vision Solutions Technologies

38. LiquiLens
• Bi-Fluidic IOL
• Gravity Based Mechanism Shifts Focal Plane on DownGaze by Altering Interplay of Fluids Against One
Another
• Capable of Providing Any Desired Spectacle Plane
Addition
• Prototype Investigations Demonstrated 20D IOL
Providing 13 Additional Diopters on Downgaze
• Can Be Designed With Any Desired Accommodation,
from +1.00 D to +40 D
• Action Independent of Ciliary Mechanism

39. LiquiLens Challenges in Presbyopia
• Too Powerful for Young Presbyopes
• No Mid-Range (Computer) Vision
• Large Incision Required Currently

40. Multifocali
ty
Mean
Accomodative
Amplitude (D)
Equivalent
Add at
Spectacle
Plane (D)
LiquiLens
Bifocal
As Desired
As Desired
Crystalens
Multifocal
1.79
Approx. 1.00
Incision
Size
(mm)
Dependence
on Ciliary
Mechanism
6-7
None
4.5
3.5
Total
ICU
Multifocal
1.7-1.9
Approx. 1.00
5.5
3.5-3.7
Total
NuLens
Multifocal
10
Variable
?
5
Total
Synchrony
Multifocal
2.55 – 3.17
1.50
5.5
3.6
Total
ReStor
Multifocal
Above 4
3.2
6
2.5
None
ReZoom
Multifocal
Above 4
2.75
6
2.5
None
SmartIOL
Multifocal
?
?
9.5
3
Total
Sarfarazi
Multifocal
7-8 (animal)
?
5
2-3
Total
PowerVision
Multifocal
?
?
?
?
Total
Quest
Multifocal
?
3.00
?
?
Total
Kellan
Tetraflex
Multifocal
2.4
1.2
5.75
2.5
Total
Akkomodative
Optic
Diameter
(mm)

41. Other Experimental Technologies in
Development
•
•
•
•
•
•
•
•
•
•
Aspheric Multifocal M-Flex Lens
Asymmetric Diffactive Twin-Set IOL
Binderflex Lens Design (sulcus) designed to transmit the contractions of
the ciliary body directly onto the IOL in order to eliminate negative effects
of the shrinking capsular bag on the accommodation process
Presbyopic Ablation
Corneal Inlay
Laser Assisted Sclerectomy
PresView Scleral Implants
Femtosecond Interlenticular Surgery (Presbyopic Lentotomy) (Gerten,
MD, Augenklinik am Neumarkt , Koln, Germany )
Pseudo Accommodative Advanced Surface Ablation
PHAKO ERSATZ

42. Phaco Ersatz (Lens Refilling Surgeries)
•
Introduced by Julius Kessler in 1966.
•
Jean-Marie Parel coined the term Phaco Ersatz at Bascom Palmer Eye Institute 1970’s.
•
Extraction of the lens contents through a sub-1 mm mini-rhexis
•
Silicon polymers have been shown to have the adequate biocompatibility and optical
properties to restore accommodation in monkeys.
•
Current efforts involve the development of safer polymers that can be cured in situ after lens
refilling and avoiding the need of UV light.
(Light Adjustable IOLs)
•
PCO prevention remains a major hurdle
•
Research is required for practical purposes as deciding the precise amount of refilling
required. (Barraquer, R, Institut Universitari Barraquer, Barcelona, Spain)