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.
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
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
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
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
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
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
35.
36.
37.
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
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
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
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.
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
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
72.
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
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