types of iol used in ophthalmology

1. Types of IOL
Dr Rohit Rao

2. HISTORY OF IOL
• K

3. 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

4. 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
HAPTEN
OPTIC

5. MATERIALS USED FOR INTRAOCULAR
LENSES
Optic materials
1.Non-foldable-rigid IOL
• Polymethyl
methacrylate(PMMA)
2.Foldable IOL
• Silicone
• Hydrophobic acrylic
• Hydrophilic acrylic
3.Rollable/Ultra-thin IOL
• Hydrogel
Haptic materials
• PMMA,
• Polyvinylidene fluoride
(PVDF),
• Polyimide (elastimide),
• Polypropylene
(prolene)

6. Polymethylmethacrylate
• Hard and rigid - Inert and non autoclavable.
• Hydrophobic – so causes adherence of cell
and bacteria
• Refractive Index 1.47 and1.55

7. Flexible Acrylic
• Hydrophilic
– Unfolds in controlled fashion
– Good uveal and excellent capsular biocompatibility
• Hydrophobic
– More prone to develop PCO
• Copolymer of phenyl ethylacrylate and
phenylethylmethacrylate.
• Good viscoelastic and three dimensional stability
• Viscoelasticity is temperature dependant with
increase elasticity at higher temperature

8. Silicone
• Elastomer Polydimethylsiloxane
• Capable of large and reversible deformations
• Good memory
• Surface deposits are common
• Additives in silicone IOL are
– UV chromophore
– Phenyl group to increase Refractive Index from
1.41 to 1.46

9. Hydrogels
• HEMA or 2 Hydroxyethylmethacrylate
• Polymerization in ethylene glycol medium
• Hydrate to form soft, swollen, rubbery mass
• Hydrophilic hence repel cells and microbes
• Refractive Index - 1.43 to 1.48

10. Truedge
• Truedge 360° Square Edge acts as a
mechanical barrier for cell proliferation
• 10° Angulation, steep vault of 0.4 mm

11. Aurofold lens
• negative aspheric hydrophilic acrylic foldable
intraocular lens made of p-HEMA material
• Truedge technology to prevent PCO
• Zero Degree Angulation

12. Aurofold lens
• p-HEMA material
• Zero degree angulation
• Disposable delivery system

13. Auro toric
• Auroflex Toric IOL has been carefully designed
with toricity on the anterior surface of the IOL.
• UV absorbing p-HEMA
• OptiCal an web based online service
www.aurolab.com/OptiCal.

14. Aurovue
• Single piece hydrophobic foldable acrylic IOL
• 3° Angulation
• disposable delivery system

15. Aurovue
• Aspheric optic (negative spherical aberration),
preloaded hydrophobic acrylic IOL.
• 3° Angulation

16. Acrysoft IQ
• Hydrophobic Acrylic IOLs
• Aspheric

17. Sensar
• Single piece hydrophobic foldable acrylic IOL
• OptiEdge® with 360° square edge, and round
anterior edge
• 5˚ angulation

18. Tecnis
• Biconvex, anterior aspheric
surface, square optic edge
• ProTEC frosted, continuous
360° posterior square edge
• UV-blocking hydrophobic
acrylic
• Haptics offset from optic

19. • enVista hydrophobic acrylic
IOL
• No glistenings
• Aberration-free aspheric
Advanced Optics
• Step-vaulted haptics
• 360° square barrier edge
enVista

20. Restor
• Single piece foldable acrylic IOL
• Apodized Diffractive Technology
• Apodization is the gradual shortening of step
heights toward the periphery of the diffractive
zone.

21. Intraocular Lens Design
• multipiece or monobloc;
• plate or open-loop style;
• angulated or planar haptics;
• special haptics for certain indications such as
sulcus, anterior chamber angle, or iris fixation;
• optic shape and edge design;
• Optic geometry for certain indications such as
toric, aspheric, or multifocal IOLs

23. Open-Loop
• Multipiece
– IOLs are held in place by exerting centripetal pressure
on capsule bag fornix and or ciliary sulcus.
• Single-Piece
– IOLs are produced in a single step from one material
– More resistant to damage with injectors
– Production process is cheaper
– May have less of a PCO-inhibiting effect

25. Haptic Angulation
• Maximize the barrier effect to migrating LECs
by pushing the IOL backwards.

26. POSITIONING OF IOL

27. POSITIONING OF IOL
1. Posterior chamber
implantation
• Ciliary sulcus fixation
• In the bag fixation
• Scleral fixation
Eg:- modified C loop type
IOL

28. In-the-bag fixation

29. Intraocular Lenses for
Insufficient Capsule Support
• In cases of PCR where IOL placement is no
longer possible, but ALC is intact, the IOL can
be placed in sulcus. (optic capture if possible)
• 0.5 diopters should be deducted
• no capsule support is given,
– angle-supported ACIOL,
– Iris-supported IOLs
– Scleral-sutured IOLs

30. Ciliary sulcus fixation

31. 2. Anterior chamber
implantation
• angle supported IOLs
• Kelman multiflex type
IOL

32. 3. Iris- fixated lens
• Fixed on the iris with
claws,loops or sutures
• Eg- Singh and Worst’s
iris claw lens

33. Intraocular Lens
Optic Design

34. Edge Design
• Sharp-edge IOL designs
– edge-glare phenomena
• IOLs with a round anterior and sharp posterior
optic edge seems to avoid this disturbing side
effect

36. Optic Geometry
• Biconvexity
– Radius of curvature of the front and back surface
are identical.
• Asymmetric biconvex optic
– Back surface curvature is relatively flat and
constant throughout most of the power range and
anterior curvature is varied for IOL power.

37. Aspherical Intraocular Lenses
• IOL has prolate surface inducing negative SA,
which should neutralize positive SA of the
average cornea.
• The aim is to increase contrast sensitivity
under mesopic conditions where the pupil is
dilated.
• little to no effect when the pupil is small.

41. Toric Intraocular Lenses
• Correcting preexisiting corneal astigmatism using
incisional techniques,
– Corneal incision on the steep axis,
– Making limbal relaxing incisions (LRIs) on the steep
axis.
– Neutralizing corneal astigmatism is the use of toric
IOLs
• Accurate axis placement of the toric IOL is critical
• 3% of toric correction is lost for every degree off axis.
• Being 10 degrees off axis results in about 1/3 of toric
correction lost.
• Being 30 degrees off results in no toric correction

43. Multifocal Intraocular Lenses
• Multifocal IOLs (mIOL) are designed to
overcome the postoperative lack of
accommodation by dividing the incoming light
onto two or more focal points.
• Two types of mIOLs:
– Diffractive
– Refractive

52. 3.Accomodative IOLs
• Special design and mechanical
properties of this IOL enable lens to
change power by a forward and
backward movement of the optic
during the contraction of ciliary
muscle.

53. • Diameter of this lens optic is 5.5 mm with an overall
diameter of 9.8 mm.
• Four haptics which are connected to the optic with a pliable
joint.
• Single piece acrylic material.
• Hinge type haptics permit movement between haptics and
optic.
• Merits
– May eliminate the need of any kind of refractive correction.
– There is no incidence of glare, haloes, ghost images and loss of
contrast sensitivity.
• Demerits
– High incidence of contraction of capsular bag.
– Loss of pliability of material at the haptic- optic junction.

58. TECNIS® symfony IOL
• Proprietary diffractive echelette design feature
introduces a novel pattern of light diffraction that
elongates the focus of the eye resulting in an extended
range of vision.
• TECNIS® symfony IOL merges two complementary
enabling technologies
– The proprietary diffractive echelette design feature
extends the range of vision.
– The proprietary achromatic technology corrects chromatic
aberration for enhanced contrast sensitivity.

62. Thank u