2. History:-
Sir Harold Ridley was the
first to successfully implant
an intraocular lens on
November 29, 1949, at St
Thomas' Hospital ,
London.
That first intraocular lens
was manufactured from
Polymethylmethacrylate
(PMMA.).
3. INSPIRATION
Inertness of intraocular plexiglass shards
A medical student, Steve Perry questioned him why was he not
replacing the lens after removal
Approximately 1000 Ridley IOLs implanted in the next 12
years
Complications
Disclocation : approx 20%
Glaucoma : 10 %
Uveitis
Went into disrepute
Strongly opposed by Sir Duke-Elders
9. 4. Fourth generation IOLs
Modern anterior chamber lens
Flexible loops and multiple point fixation
Advantages – more stable, better design, less
complications
Disadvantages – anterior chamber is not the
physiological site for IOL
17. 3. Iris- fixated lens
Fixed on the iris with
claws,loops or sutures
Eg- Singh and Worst’s
iris claw lens
18.
19. ADVANTAGES OF IN-THE-BAG
PLACEMENT
Proper anatomical site
Symmetrical loop placement
Intraoperative stretching or tearing of zonules is avoided
Minimimal magnification (<2%); (20-30% aphakic glasses, 7-12% aphakic contact
lens, ACIOL 2-5% )
Low incidence of lens decentration and dislocation
Maximal distance from the posterior iris pigment epithelium, iris root, and ciliary
processes
Loop material alteration is less likely
Safer for children and young individuals
Reduced posterior capsular opacification
20. Parts of an IOL
OPTIC
Part of the lens that focuses
light on the retina.
HAPTIC
Small filaments connected to
the optic that hold the lens in
place in the eye
HAPTE
N
OPTIC
22. Different types of haptic angulation relative to the
plane of optic:-
For posterior chamber lens:-
100 anterior angulation to keep the optic part
away from the pupil.
For anterior chamber lens:-
Posteriorly angulated lens to vault the
intraocular lens away from the pupil
23. ANGULATED HAPTICS ALLOW FOR ADEQUATE PUPILLARY
CLEARANCE AND ADHESION TO THE POSTERIOR CAPSULE
24. LENS CHEMISTRY
(Optic Materials)
RIGID MATERIALS
PMMA
(Polymethylmethacrylate)
Water content <1%
Refractive index 1.49
Usually single piece
FLEXIBLE MATERIALS
Silicones
Acrylics
Hydrophilic
Hydrophobic
25. FLEXIBLE MATERIALS
Silicone
Polymers of silicone and oxygen
Since 1984; first material for foldable IOLs
Hydrophobic (contact angle with water of 99°)
1.41 to 1.46
3 piece
Thick optics (need larger incisons)
Handling is difficult; loading into injector
Bacterial adhesion
Anterior capsule rim opacifies quickly
Low PCO
Lowest threshold for YAG laser damage
Glistenings
Adherence of silicone droplets
26. HYDROPHOBIC ACRYLIC
Copolymers of acrylate and methacrylate
1993 (Acrysof 3-piece lens)
Most successful IOLs today
Angle of contact with water is 73°
3-piece or 1-piece designs
1.44 to 1.55
Easy handling; prone to mechanical damage
At least a 2.2-mm incision
Low PCO rates
Good resistance to YAG laser
Photopsias
Glistenings
BSS packaging (reach 4% water content before implantation)
27. HYDROPHILIC ACRYLIC
Mixture of hydroxyethylmethacrylate (poly- HEMA) and
hydrophilic acrylic monomer
End of the 1980s
1.43
18 -26% water content
Contact angle with water is lower than 50°
Single piece
Easiest to handle; less mechanical/YAG laser damage
Sub-2-mm incisions
Higher PCO rate
Low resistance to capsular contraction
Calcium deposits
30. Mindset of the Presbyopic Refractive
Patient
Patients are interested in lifestyle, not pathology and
are happy to pay for the enhanced quality of life
Old paradigm: Patient want to see better than they did
with their cataracts
New paradigm: Patients want to see better than they
did before they developed cataracts
31. MULTIFOCAL IOLs
Single IOL with two or more focal points
Types
Refractive
Diffractive
Combination of both
32.
33. REFRACTIVE MULTIFOCAL IOLs
Bull’s eye lens
Concentric rings of different
powers
Central addition surrounded by
distance optical power
Annulus design
3-5 rings
Central for distance vision
Near vision ring
Distance vision ring
34. 12345
Bright light/ Distance dominant zone
Large Near dominant zone
Low light/ Distance
dominant zone
Distance zone
Near zone Aspheric transition
REFRACTIVE MULTIFOCAL IOLs
35. Silicone MIOLs
Array multifocal IOL (AMO)
First FDA approved foldable MIOL
5 concentric zones on its anterior surface
50% distance, 37% near, 15% for intermediate vision
Acrylic MIOLs
ReZoom multifocal IOL (AMO)
Zone 1,3 and 5 : distance
Zone 2 and 4 : near
60% distance, 40% near and intermediate
PREZIOL (Acrylic)(Care Group)
Manufactured by Indian company
Also available as non foldable PMMA lens
40. Based on the average
corneal-surface
wavefront-derived
spherical aberration
41. Tecnis Multifocal IOLs (AMO)
ZM900 (Silicone)
ZA00 (Acrylic)
Optic Diameter 6.0 mm
Optic Type
Modified prolate anterior surface
Total diffractive posterior surface
42. Acrysof IQ ReSTOR (Alcon)
Acrylic diffractive multifocal IOL with apodized design
Optic diameter- 6 mm
Refractive for distance, and a diffractive lens for near.
16 rings distributed over central 3.6 mm
Peripheral rings placed closer to each other
Central rings : 1.3 µm elevated, near vision
Peripheral 0.2 µm elevated, distant vision
Anterior peripheral surface is modified to act as refractive
design
44. INTRAOPERATIVE EXCLUSION
Significant vitreous loss during surgery
Pupil trauma during surgery
Zonular damage
Capsulorhexis tear
Capsular rupture
Eccentric CCC
45. SPECIAL CONSIDERATIONS FOR
MfIOLS
Counselling (most important)
Accurate Biometry
Power Calculation
Surgical Technique
Round, centered CCC completely overlapping the lens
optic
Removal of all viscoelastic from behind the lens
46. Loss of contrast sensitivity
Glare and halos
scattering of light at the dividing line of the different zones
improves with bilateral implantation, because of “a bilateral
summation” effect
Less satisfactory visualization of fundus- difficulty in vitreo-
retinal procedures
Requires adaptation
47. ACCOMMODATIVE IOLs
Monofocal IOL
Changes position inside the eye as the eye's focusing
muscle contracts
1 mm of anterior movement of lens = 1.80 D of
accommodation
Mimicking the eye's natural ability to focus
48. 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
49. 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
50.
51. 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
52. Silicone
Crystalens (Bausch & Lomb)
Only FDA approved IOL for correction of presbyopia
Hydrophilic Acrylic
BioComFold type 43E (Morcher GmbH)
1CU (HumanOptics AG)
Tetraflex (Lenstec Inc.)
53.
54. Modern cataract surgery is more of refractive
surgery.
Myopia & hypermetropia can be corrected using
appropriate spherical powers of IOL’s.
However approximately 20% of patients who
undergo cataract surgery have 1.25D of corneal
astigmatism or more.
It can be corrected with Toric IOL’s.
55. Other options for correction of co-existent
cataract and astigmatism
LRI during cataract surgery( upredictable results)
Laser procedures postoperatively (are associated with
new set of complications).
56. First introduced by Shimizu et al in 1994.
It was nonfoldable 3 piece toric IOL made from
PMMA.
It had oval optic with loop haptics ,available in
cylinder power 2-3 D.
Postoperatively 20% IOL’s rotated > 30 degrees and
50% IOL rotated about 10 degrees.
57.
58. Factor Affecting Rotation of Toric
IOL
(1) IOL Material-
Hydrophobic Acrylic < Hydrophilic Acrylic < PMMA < Silicon
(2) Overall IOL diameter - Larger diameter prevents rotation .
Toric IOL’s are available nowadays in 11-13 mm overall
diameter.
(3) Haptic Design-
Initial concept
- Loop haptics prevent early rotation .
- Plate haptics prevent late rotation.
Recent concept – No difference in incidence of post operative
rotation between plate and loop haptics provided material of
both loop and plate is same.
60. Facts
20% of patients with cataract have astigmatism >1.25
D
Every incision on cornea induces additonal
astigmatism (SIA).
Implantation of monofocal lens will require
distance and near correction both in these cases.
B/L Toric IOL’s give high level of spectacle
independence(97%).
Requirement of near correction can be overcome by
multifocal toric IOL(AcriLisa multifocal toric IOL)
63. Keratometry
Can be done with
Manual keratometer
Automated keratometer
Corneal topography
K readings from all the three show high repeatability
and are comparable.
Manual keratometer should be calibrated regularly.
64. Corneal topography is required in case of unusual
reading & poor quality mires.
Precautions
Reading must be quick to avoid drying of cornea.
Don’t rub on the cornea.
Centration must be proper.
65. Surgically Induced Astigmatism
Every incision changes the cornea.
Closer to the centre & larger the incision more effect
on corneal curvature.
Other factors affecting it are preoprative corneal
astigmatism, suture use and patient’s age.
In addition there is variability from patient to patient.
Overall effect can be summed up with vector analysis.
66. SIA Calculation
Obtain SIA calculator
Fill it for 20-30 cases minimum
Be precise about axis and incision
Calculator auto calculates SIA
67. AcrySof Toric IOL Calculator
Data input
Patient data
Keratometry
IOL spherical power
Surgically induced
astigmatism
Incision location
67
68. Output screen
Recommended IOL model
and spherical equivalent
power
Optimal axis placement
Magnitude and axis of
anticipated residual
astigmatism
68
70. STEPS
A) Reference marking
- Done prior to surgery with patient upright
- Two reference markers placed at limbus 180 degree apart
- Used to align marking instuments for placement of axis
marks
B) Axis marking : Using reference marks as a guide the
patient eye is marked accurately at two positions 180
degree apart
TIPS:-
- Dry the conjunctiva with a swab
- Enhance marking at 3-9 o clock
- It lasts throughout surgery
71. Surgery
• Standard phacoemulsification
• Incision size 1.5 – 3.4 mm
• Well centered rhexis with diameter 5- 5.5 mm with 360
degrees overlap of IOL margin
• Marks on IOL indicate flat meridian or plus cylinder axis
of toric IOL
• Cohesive viscoelastics are preferred.
72. • IOL alignment
Tap (“nudge”) IOL down into capsular bag to seat
lens onto the posterior capsule.
Gross alignment
OVD removal
Final alignment
If overshoots
73. If any compromise of zonular integrity or capsule
occurs please switch to standard non toric IOL
POST OP XIS ALIGNMENT-
Slit Lamp with dilated pupil
Wavefront aberrometry in undilated pupil
Realignment should be done in < 2 wks
74. Complications
Rotational stability is critical
to effectiveness of toric IOLs.
1° rotation results in 3.3 %
IOL power loss
30° rotation negates
cylindrical correction of toric
IOL
Further rotation induces more
astigmatism
74
75. IOL IMPLANTAION IN SPECIAL
SITUATIONS
ABSENCE OF CAPSULAR SUPPORT
Scleral fixation (suture/glue)
Iris fixated
ACIOLs
PEDIATRIC AGE GROUP
Heparin coated
Multifocal IOLs
DRUG ELUTING IOLs
Triamcinolone acetonide
Dexamethsone
Antibiotic
Diclofenac sodium (0.2 mg/mL)
Mitomicin C (0.2 mg/mL)
Colchicine (12.5 mg/mL) and 5-fluorouracile (10 mg/ml)
Anti-VEGF
76. ANIRIDIA IOLs
Various designs
Overall size = 12.5 to 14 mm
Optic diameter = 3.5 to 5 mm
Central clear optic
Surrounding colored diaphragm
78. Primary vs secondary implantation
Primary implantation – use of IOLs during surgery for
cataract
Secondary implantation – implantation of IOL to
correct aphakia in a previosly operated eye
79. PHAKIC IOLs
Implantation of IOL without removing natural
crystalline lens.
ADVANTAGE: Preserves natural accommodation
Mostly used in Myopic eyes: -5 to -20 DS
Also used in Hyperopic eyes
Concern in Hyperopes:
More chances of endothelial damage
Increased risk of angle closure glaucoma
Life-long regular follow up required.
82. Implantable Collamer Lens (ICL)
Pre-crystalline lens made of silicone or collamer.
Length of the lens = white-to-white limbal diameter -
0.5 mm
Overall size- 11-13 mm
Otical zone - 4.5-5.5 mm
Toric model also available
83. COMPLICATIONS:
Constant contact pressure
Cataract
Ciliary body reactions
Prevent free passage of aqueous.- Iridectomy required
SPINNAKER EFFECT: Blowing sail of a boat
84. IRIS FIXATED PHAKIC IOL
VERISYSE/ARTISAN (AMO/OPTECH)
Made of PMMA
convexo-concave
Length = 7.2 – 8.5 mm
Optic size = 5-6 mm
Haptics fixed to iris –claws
85. IRIS FIXATED PHAKIC IOL
ADVANTAGES OVER ICL:
Customized smaller size possible
Easier examination from end-to-end
COMPLICATIONS-
Early post op AC inflammation
Glaucoma
Iris atrophy on fixation sites
Implant dislocation
Decentration
Endothelial cell loss
86. ANGLE FIXATED PHAKIC IOL
TWO TYPES –
4 point fixation
Baikoff’s modification of Kelman type haptic design
NuVita MA20 (Bausch and Lomb)
3 point fixation
Vivarte (IOL Tech)
Separate optic and haptic
88. PIGGYBACK IOLs
An intraocular lens that “piggybacks”
onto an existing intraocular lens or two
IOLs are implanted simultaneously.
First IOL is placed in the capsular bag.
The second (piggyback) IOL is placed in
the bag or sulcus.
89. 2 types-
classically- secondary iol in bag
Add on type- secondary iol in sulcus
90. Easier to place 2nd IOL than to explant IOL & replace
it
Lesser risk
More predictable
Can change power with time-by adding IOL or
explanting an IOL
Better image quality
Increased depth of focus
91. COMPLICATIONS
Interlenticular opacification
(Interpseudophakos Elshnig’s pearls)
(RED ROCK SYNDROME)
Unpredictable final IOL position
96. HOW TO OVERCOME ?
Strategy 1:
Lens with negative spherical aberrations to balance the
normally positive corneal spherical aberrations
Strategy 2:
Lens with minimum spherical aberrations so that no
additional spherical aberration is added to the corneal
spherical aberrations
97.
98.
99.
100. ASPHERIC IOLs
Need perfect centration
Decreased depth
perception
More expensive
Need corneal topography
for optimal results
Not much difference in
photopic conditions and in
older age group
Not for previous hyperopic
refractive surgery
Better contrast sensitivity
Better mesopic vision
Night time driving
AcrySof® IQ Aspheric IOL
patients had an average
increase of 130+ feet (vs
the control lens) in which
to stop after identifying a
warning sign
Better option for younger
patients
Editor's Notes
I am starting to see this shift every day in my practice