some information about intraocular lens materials, designs; and their effect on surgery and visual function. I'm sorry that i one i previously uploaded was the wrong file.

1. Nawat Watanachai
2013

2. 1949 Sir Harold Ridley (UK)

3.  1952 : Baron
(FRA)
 1953 : Edward Epstein
(USA)

4.  More than 250 models of IOL to be chosen
 Which one is the best choice?

5. Which one is the best (+affordable) choice?
 Patient’s satisfaction
▪ Good VA/ wide range of vision
▪ Less aberration/ glare
▪ safe
▪ Reasonable price

6. Which one is the best
(affordable) choice?
 Doctor’s satisfaction
▪
▪
▪
▪
▪
Easy to handle/ insert/ remove
Chemically inert/ noncarcinogenic/ nonallergic
Low bacteria and fungus adherence
Durable
Others :
▪ high RI/ absorp UV/ transparent for visible light

7. Materials
 Optical part : clear/ biocompat/ durable
 Haptic part
Designs
 Optical part : less PCO/ less aberration/ UV filter
 Haptical part : stability/ easily insert+remove

8. Optics
 Glass
 Silicone-based
 Acrylate-Methacrylate-Based
Haptics






Silicone-based
Acrylate-Methacrylate-Based
Polyamide
Polyethylenglycolterephthalate
Polypropylene
Polyimide

9.  Glass
 Silicone-Based
 Acrylate-Methacrylate-Based
 Polymethylmethacrylate monomer (PMMA)
 Rohto, PH55MB, P366UV, EZE55, SF65
 Acrylic polymers
 Hydrophilic Acrylic polymers
 Hydrogel
 Hydrophobic Acrylic polymers
 Acrysof, Akreos, Sensar, Clariflex, Tecnis

11.  Refractive index = 1.49
Advantages
Cheap
 Transmit a broad light spectrum
 Surface modification
 Good biocompatibility
 Large optic center

12. Disadvantages





Large incision size
Brittle
Monomeric release
Not autoclavable
Injure cornea

13.  one-piece PMMA PC-IOL
PH55, MC60BM, RohtoRE06F,
Epoch651A,Crystal
 for Scleral fixation
P366UV, SF65
 AC IOL
S122UV

14. Disadvantages
 The lowest threshold for YAG laser damage
 Discoloration of lens to a tan-brown color
 Irreversible adherence to silicone oil
 Foggy when exposed to airflow
 Slippery when wet

15.  SI-30 design
(AMO)
 SI-40 design
(AMO)
 CeeOn Edge 911 (Pfizer)
 Clariflex
(AMO)
 SoFlex SE
(B&L)

16. Advantages
 Good biocompatibility,optical quality
 Foldable
 Good laser resistance
 Little or no surface alteration or damage from
folding
 Low damage potential when touching the
corneal endothelium

17. The Hydroview lens (B&L)
The MemoryLens (Ciba Vision)
The CenterFlex Lens (Rayner)

18. Developed for IOL
 Pure acrylic polymer (flexibility) +
Methacrylic polymer (durability)

19. Advantages
 Foldable
 High refractive index (1.55)
 Good biocompatibility, optical quality
 High tensile strength VS hydrophilic
 Low water content/ no hydration require

20. Disadvantages
 Limit (very) long term study
 Easily get forceps marks
 Sticky surface

21. PMMA
RI
1.49
Hydrophilic
acrylic
1.45-1.52
Hydrophobic
acrylic
silicone
1.45-1.55
1.41-1.46
Biocompatibility
+
++
++
+++
Surface
smoothening
++
+
+
+
Surface
modification
-
+++
+++
++

22. PMMA
Hydrophilic
acrylic
Hydrophobic
acrylic
silicone
Incision size
Large
Smallest
Smallest
small
Non-Slippery
when wet
+
+
+
--
Unfolding
0
+
-
-
Less
mechanical
corneal
damage
--
++
++
++

23. PMMA
Hydrophilic
acrylic
Hydrophobic
acrylic
silicone
Less
pigment
adhesion
++
-
++
++
Less LEC
outgrowth
++
--
++
+
Laser
resistance
-
++
++
--
++
+
+
---
Less Silicone
oil adhesion

24.  Optical part : clear/ less PCO/ less aberration
 Haptical part : stability/ easily insert+remove

26.  germinal cells
 migrate centrally from equator
 contribute to the formation of the
nucleus , epinucleus and cortex
throughout life

29. Square posterior edge

30. Square posterior edge
360 barrier

31. ProTEC™ 360° Edge Design
 The 360° square edge
 Uninterrupted contact with the
posterior capsular bag even at
the haptic-optic junction
 The frosted-edge design
minimizes edge glare
35

32. PCO
Acrysof
Posterior
square edge
+
Akreos
+
Tecnis
+

33. IOL design : Spherical aberration

34.  Spherical aberrations of the human eye vary with age

 Cornea : always gives positive spherical aberrations
 Young lens :negative spherical aberrations
 old lens : positive spherical aberrations
  glare,reduce contrast

38. IOL With No Residual Spherical
Aberration
IOL With Residual Spherical
Aberration*
In aviation-type visual performance testing, vision in low-light conditions
(5 mm pupil)
Does not allow a lens to bring light rays to an ideal focal point
The effect may be a reduction in contrast sensitivity or visual function *

39. AcrySof (+20D)
Silicone (+20D)
 Spherical IOL
 The thicker the lens, the
greater the spherical
aberration
 More power, increase IOL
thickness
 IOL thickness <-- RI
* DA Atchison, JCRS 1991

40. Aspheric IOL
 Aspheric optics align the light rays to compensate for
positive corneal spherical aberration, resulting in enhanced
image quality.
*
Smith, G., Atchinson D.A., (1997) The Eye and Visual Optical Instruments. Cambridge University Press, Cambridge, United Kingdom, pp. 667.

41.  Acrysof IQ ( SN 60 WF)
(Alcon)
 Akreos AO
(Bausch & Lomb)
 Tecnis Z 900
(AMO)

42.  IQ’s posterior aspheric optic
 Compensates for spherical aberration by addressing
over-refraction at the periphery
 No increase in edge thickness
 Lenc become thinner
Aspheric
IOL

44. Trim both anterior and posterior surfaces

45.  Creates asphericity by elevating the peripheral
portion of the anterior lens surface
 Edge thickness of approximately .60 mm

46. Spherical aberration
Acrysof
Akreos
Tecnis
Correction
area
Trim
posterior
center
Trim
anterior /
posterior
center
Add
anterior rim
Lens
thickness
Thinner at
center
Thinner at
center
Thicker at
rim

47. 51
1. Schwiegerling J. Survey of Ophthalmology, 2000.

48. may negatively impact:
 Visual acuity
 Contrast sensitivity
 Functional vision
Abbe numbers
The higher the Abbe number
- lower the chromatic aberration
- higher the retinal image quality
52
Negishi K, et al. Arch Ophthalmol .2001.

49. A higher Abbe number is better: this means less
chromatic aberration and better optical performance
Acrysof (Alcon)
37
Akreos (B&L)
47
Tecnis (AMO) 55

50. A higher Abbe number is better: this means less
chromatic aberration and better optical performance
Acrysof (Alcon)
37
Akreos (B&L)
47
Tecnis (AMO) 55

51. 55
1. Schwiegerling J. Survey of Ophthalmology, 2000.

52. Acrysof (Alcon)
Akreos (B&L)
Tecnis (AMO)
ALL CHECKED

53. UV blocker (350-400 nm)
Blue blocker (blue 400-480 nm)

54.  Filters for
 invisible UV rays
 some visible blue rays
 Block visible blue rays?
 Blue ray :
 7% of cone related photopic vision
 35% of rod related scotopic vision

55. Patients with blue light-filtering IOLs
had faster response times in driving
 Gray R. J Cataract Refract Surg. 2011
Blue light-filtering IOLs helped to lower
glare disability and increase photostress
recovery time
 Hammond. Clin Ophthalmol. 2010

56.  Block only the UV light
 NOT the BLUE

57.  Blue light is proven to be essential for optimal scotopic
vision*
 Blue light provides 35% of scotopic sensitivity*
61
*Mainster MA. Br J Ophthalmol. 2006.

58.  Interest in blocking blue-light is motivated by the
unproven hypothesis that phototoxicity from
environmental light exposure can cause AMD*
 10 of 12 major epidemiological studies show
no correlation between AMD and lifelong light
exposure
62
Mainster MA. Presented at ASCRS .2009.

59. Acrysof
Akreos
Tecnis
118.7
118.5
118.8
Hydrophobic
acrylic
yes
yes
yes
RI
1.55
1.458
1.47
Abb no
37
47
55
UV blocker
+
+
+
Blue blocker
+
-
-
A

60. Acrysof
Akreos
Tecnis
0
10
5
Haptic shape J
Loop
L
Block
Spherical
aberration
Yes
Post.
trim
Yes
Ant. + Post.
trim
Yes
Ant.
add
Thickness at
same power
thinnest
fair
thickest
Haptic
angulation

61.  Toric IOLs
 Multifocal IOLs
 Accommodative IOLs
 IOLs for very small incision
 Adjustable power IOLs
 Phakic IOLs

62. To reduce pre-existing astigmatism
Need appropriate centration, fixation and
stability without rotational movement

63. Preexisting regular astigmatism 0.75>D
 More problem if axis is away from 90/ 180’
Regular and smooth keratoscopic mires
with orthogonal steep and flat meridians

64. Irregular astigmatism
Distorted keratometry
A lifelong patient history of satisfaction with
spectacular cylindrical corrections
Large eyes (white-to-white distance > 12
mm)

65. Postoperative rotation or decentration will
cause problems
negative effect can occur if the lens axis
rotates by more than 30’

68. Coming soon

70. My opinion : when to consider toric IOL
 Astigmatism >1.5 at 90’ or 180’
 Astigmatism 1.0 at other axes

71.  distance and near vision
 Require
 astigmatism control
 precise biometry
 Types of multifocal IOLs
 Refractive multifocal IOLs
▪ Spheric
▪ Aspheric
 Diffractive multifocal IOLs

73. Array Design multifocal IOLs (AMO)
 Three-piece
 Silicone with PMMA haptic
 zonal multifocal optic with 5 concentric zones
▪ Zone 1, 3,5 – distance
▪ Zone 2,4 -near

74.  Array Design multifocal IOLs (AMO)
 Anterior spheric refractive surface and multiple
posterior refractive surface
 Power 0-5.0 D
 vision
▪ Distance vision 50 %
▪ Intermediate vision 13 %
▪ Near vision 37 %

75.  The ReSTOR (Alcon)
 Single-piece
 The diffractive grating is present in the center 3.6 mm
 The largest diffractive step is at the lens center
▪ send most energy to the near focus
 As the step move away from the center,they gradually
decrease in size ,blending into the periphery
▪ sending more proportion of energy to the distance focus

76. ▪ When the pupil is small or medium size
▪ provides appropriate near and distant vision
▪ large pupil situations
▪ becomes a distant-dominant

77. Problems and complications
 loss of contrast sensitivity
 pupillary apertures <2 mm
 decrease in distance VA
 decentered > 2 mm
  loss of near VA
 visual performance is minimally affected by
decentration and changing pupillary size

78. Problems and complications (cont’d)
 Ghosting of images and glare from oncoming light

79. Refractive
Diffractive
Near VA
-
+
Distance VA
=
=
Contrast
sensitivity
better
worse
glare
Less
more
Array
AcrysofReSTO
R
TecnisMF

80. ▪ Pros
▪ Offer ranges of vision
▪ Cons
▪ Not offer good vision in all ranges
▪ 30% still need reading glasses
▪ PCO will cause more visual problems
▪ More glare
▪ Less contrast sensitivity
▪ Need good IOL positioning
 Round CCC
 Clear capsular bag
 Tilt < 5-6’
 Price tag

81. To restore accommodation
 forward movement of the optic during
accommodation
It is still not known whether the ability of
these new IOL design will not be impair by
long-term postoperative fibrosis/
opacification within the capsular bag

82.  CrystaLens
 The lens is hinged adjacent to the
optic
 with accommodative effort
▪ redistribution of ciliary body mass
▪ result in increased vitreous pressure
▪ move the optic forward anteriorly
within the visual axis
▪ creating a more plus powered lens

83.  synchrony IOL (Visiogen Inc.)
 One-piece silicone lens
 The anterior lens has a high plus power beyond that
required to produce emmetropia(30-35 D)
 the posterior lens has a minus power to return the eye
to emmetropia
 The distance between the two optics
• minimum in the un-accommodated state
• maximum in the accommodated state
 No long term data

84. FluidVision
Pocket filled with
clear liquid
silicone

86. • Calhoun lens
•University of California at San
Francisco, San Francisco,
California

87. There is no BEST IOL for all
Find the proper one for each patients