Phakic intraocular lenses (IOLs) are artificial lenses designed to correct moderate to high refractive errors while preserving the natural crystalline lens, making them a suitable option for patients with severe myopia and hyperopia. They have several advantages over traditional laser procedures, such as maintaining corneal structure, predictable results, and rapid visual recovery, although they also carry risks like intraocular complications. The document outlines the history, various types of phakic IOLs, surgical procedures, and potential complications associated with their implantation.

1. PHAKIC IOLs
RUMI DAS

2. Introduction
 Artificial lenses implanted in the anterior or posterior
chamber of the eye in the presence of the natural
crystalline lens to correct refractive errors.

3.  Phakic IOLs an evolving technique in the field of
refractive surgery for the correction of moderate to
high refractive errors.
 Patients with high myopia (above -10 diopters)
constitute only about 2% of the myopic population but
13-15% of patients presenting for refractive surgery
belong to this group.

4. Lasik is justifiably still the most widely
practiced modality of refractive surgery
because of –
 High level of comfort
 Quick recovery
 Stable predictable results
 Ability to perform bilateral treatment in one sitting.

5. But when it comes to higher grades of
refractive error it has the following limitations:
 Significant residual error.
 Loss of best spectacle corrected visual acuity.
 Risk of iatrogenic keratectasia when excessive ablation
done or residual bed is too thin.
 Induction of tear film abnormalities.
 Induction of higher order aberrations, which leads to poor
contrast sensitivity,
 Limitation of night vision and diminished quality of vision.

6. Advantages of Phakic IOLS
in High Refractive Errors
 Preservation of architecture of cornea
 Predictable refractive results.
 Preservation of accommodation
 Predictable healing.
 Rapid visual recovery.
 Stable post-operative refraction.

7.  Reversible and adjustable.
 Cheap , no costly equipment like a lasik unit is
necessary.
 The technique of implanting a phakic IOL is similar in
many ways to phacoemulsification and a good anterior
segment surgeon can easily incorporate it is his
practice.

8. Challenge in Phakic IOL
Surgery
 Limited space to carry out all procedures

9. Indication for Phakic IOLs
Any refractive error which is unsuitable for LVC could be
considered for phakic IOLs
 Myopia beyond -12D
 Hyperopia beyond +4D
 Initial corneal thickness <480 microns.
 Residual bed after LASIK is likely to be <280 microns.

10. History
 1889
Clear lens extraction for the correction of myopia
Fukula in Austria/Germany : FUKULA SURGERY
Abandoned due to complications
 1950s
Correcting myopia by inserting a concave lens into Phakic eye
 1988
Baikoff : anterior chamber angle fixed IOL
 Mid 1980s
Posterior chamber phakic IOLs : Fyodorov
 1991
Artisan- Worst iris claw lens

11. Phakic IOL - Options
There are primarily three sites of fixation
ANTERIOR CHAMBER ANGLE – SUPPORTED
e.g BAIKOFF, NUVITA lenses
ANTERIOR CHAMBER IRIS – FIXATED
e.g VERISYSE
POSTERIOR CHAMBER IOLS
e.g STAAR ICL (Implantable Contact Lens) and PRL (Phakic Refractive
Lens)
ICL is more widely used.

12. Figure 3: Schematic representation of phakic IOL locations:
a. Angle supported. b. Iris clip. c. Posterior chamber shown in dotted
lines since it is covered by Iris.

13. Optical Advantages of
Phakic IOLs
 Phakic IOLs are placed much closer to the nodal point
of the eye.
 Hence, effective optic zone of phakic IOL is 1.25 times
on corneal surface.

14.  Slight improvement in visual acuity in higher grades of
myopia - because reduction of minification effect
 Since cornea is untouched quality of vision is better
after phakic IOL implants than LVC.

15. General criteria for implanting Phakic IOLs
Stable refraction (less than 0.5 D change for 6 months)
Clear crystalline lens
Ametropia not suitable/appropriate for excimer laser surgery
Unsatisfactory vision with/intolerance of contact lenses or spectacles
Anterior chamber depth greater or equal to
3.2 mm for Verisyse ( iris claw lens)* and angle supported PIOLs
^2.5 mm for posterior chamber PIOLs*
A minimum endothelial cell density of *
≥3500 cells/mm² at 21 years of age
≥2800 cells/mm² at 31 years of age
≥2200 cells/mm² at 41 years of age
≥2000 cells/mm² at 45 years of age or more
No ocular pathology ( corneal disorders, glaucoma, uveitis,
maculopathy, etc
* According to FDA

16. Advantages & Disadvantages
of Phakic IOLs

17. ADVANTAGES DISADVANTAGES
Potential to treat a large range of
myopic, hyperopic and astigamtic
refractive error.
Potential risk of an intraocular
procedure ( e.g endophthalmitis)
Allows the crystalline lens to retain its
function preserving accomodation.
Nonfoldable models require large
incision that may result in high
postoperative astigmatism
Excellent visual and refractive results
(induces less coma and spherical
aberration than LASIK)
Highly ametropic patients may require
additional photorefractive surgery (
Bioptics) for fine tuning the refractive
outcome.

18. ADVANTAGES DISADVANTAGES
Removable and exchangeable May cause irreversible damage (i.e
endothelial cell loss, cataract
formation, glaucomatous optic
neuropathy)
Frequently improves BSCVA in
myopic eyes by eliminating
minification effect of glasses
Implantation in hyperopic patients can
be followed by loss of BSCVA due to
loss of magnification effect of glasses.
Results are predictable and stable Other complications are common:
pupil ovalization, induced astigmatism,
chronic uveitis, pupillary block,
pigment dispersion.

19. Power Calculation for Phakic
IOLs
There are 3 parameters that are essential are-
 Preoperative Spectacle power
 AC Depth.
 Horizontal and vertical radii of curvature of cornea.

20. Ancillary tests required
 Unaided and best corrected VA
 Anterior and posterior segment evaluation
 White - to - white (w-w) measurement
 High frequency (50 MHz) ultrasound biomicroscopy
 Corneal endothelial cell count

21. Figure 5: Verisyse and ICL power calculation
charts

22. Deciding the size
Anterior Chamber Angle Supported Phakic IOLs
 Overall Length of IOL : 11.5 mm to 14.0 mm with 0.5
mm intervals.
 W-W measurement ( with addition of 0.5 – 1.0 mm) –
most commonly used tools.
Others - Intraoperative AC sizer
Anterior segment OCT

23. Ac iris-fixated phakic IOLs
One size fits all length ( 8.5mm), sizing is not important
Sizing posterior chamber phakic IOLs
Sizing of the posterior chamber phakic IOLs is extremely
important – for getting appropriate vault
 UBM and AS OCT – to measure sulcus-to-sulcus distance (
best tools to measure sulcus to sulcus distance)
 w-w measurement plus 0.5 mm

24. Artemis high-frequency (50 MHz) 3D-digital ultrasound imaging of the
anterior segment. Red arrows indicate angle-to-angle distance; yellow
arrows indicate sulcus-to-sulcus distance.

25. AC Angle supported Phakic
IOL

26. Lowered vaulting to 20
degree
Thinned optic edge
Increased distance
from endothelium 0.6
mm
Baikoff ZB5M NuVita MA20
New rigid PMMA lens
Total diameter – 5mm
Real optic diameter
4.5mm
Edge decreased by
20%

27. Other models of angle
supported PIOLs
Two rigid PMMA devices:
 ZSAL-4
 Phakic 6
Three foldable hydrophilic acrylic IOLs:
 Vivarte
 I-CARE
 Acrisof AC
One foldable “two parts” silicone/PMMA IOL:
 Kelman-duet

28. Rigid PMMA angle-supported ZSAL-
4 lens.
Rigid PMMA angle-supported
Phakic 6 lens.

29. Foldable hydrophilic acrylic
angle-supported Vivarte lens.

30. Foldable hydrophilic acrylic angle-supported I-CARE lens (A and B).
Ultrasound biomicroscopy (UBM) showing the position of the haptic in the anterior
chamber angle (C).

31. Surgical Procedure
 Topical pilocarpine
 Topical or peribulbar anaesthesia
 Incision
 Cohesive viscoelastic
 Lens is introduced, footplate is inserted in the
iridocorneal angle, second haptic is then placed, lens
is then rotated in place
 Periphery iridectomy done
 Incision is closed

32. Foldable “two parts” (Silicone optic/PMMA haptics) Kelman-Duet lens (A). The
haptics are implanted initially through a small incision (B), then the optic is
injected (C). The complex optic-haptics is assembled inside the anterior
chamber (D).

33. Complications
 Haloes and glare
 Pupillary ovalization
 Endothelial damage
 Elevation of intraocular pressure
 Uveitis
 Cataract
 Retinal detachment
 Rarely – urrets – zavalia syndrome, malignant
glaucoma, endophthalmitis

34. Pupil ovalization 2years after implantation
of an angle-supported phakic IOL (A).

35. At 5years, progressive ovalization was observed and the lens was
explanted (B).

36.  Have been largely given up because of complications
like progressive pupillary distortion and corneal
decompensation.
 At present Alcon is conducting trials with an angle
fixated IOL which may become available for clinical
usage shortly.

37. IRIS-FIXATED PHAKIC IOL

38. IRIS-FIXATED PHAKIC IOL
 Midperipheral fixation by a claw mechanism
Artisan/Verysise lens. Detail of the mid-peripheral iris
stroma enclavated by the haptic claw.

39. Iris-fixated Verisyse lens in situ.
Originally designed by Jan worst and named Lobster
claw lenses and subsequently renamed as
ARTISAN lenses and now marketed as VERISYSE.

40. Verisyse - Iris Clip Lenses
 Made up of PMMA and have an overall diameter of
8.5mm.
 In the power range -3D to -15.5D - available in 6mm
optic size
 -15.5D to -23.50D and +1D to +12D – available in
5mm optic size.
 Toric versions are also available now.
 Artiflex – are foldable version with silicon optics and
PMMA haptics – ( introduced through a 3mm incision )

41. In september 2004, the FDA approved the first
phakic IOL..
 The Verisyse(AMO/Optotec,USA Inc.) was approved for –
 Myopia ranging from -5 to -20 D
 Astigmatism </= to 2.5D
 Adults 21 years of age or older
 With anterior chamber depth( ACD) of 3.2 mm or
greater and Shaffer grade II as determined by
Gonioscopy.

42. Artisan/Verysise lens
{FDA-approved models}
(A) 204 (6.0 mm optic) and (B)
206 (5.0mm optic) for
the correction of myopia.

43. (A) Foldable iris-fixated Artiflex lens.

44. (B) Foldable iris-fixated Artiflex lens.

45. Indications of Iris Claw lens
 Treatment of refractive errors after penetrating
keratoplasty.
 Treatment of Anisometropic Amblyopia in children.
 Secondary implantation for Aphakia correction.
 Treatment of refractive errors in patients with
keratoconus.
 Correction of progressive high myopia in
pseudophakic children
 Postoperative anisometropia in unilateral cataract
patients with bilateral high myopia

46. Procedure
 Topical pilocarpine
 Topical / peribulbar anaesthesia
 Incision (corneal, limbal or scleral tunnel incision)
 Cohesive viscoelastics
 IOL insertion
 Enclavation done
 Closure of incision

47. Enclavation spots are marked on the cornea to guide fixation.

48. The incision is enlarged to the appropriate size.

49. B) The foldable Artiflex (Veryflex) lens is introduced vertically with a
special spatula through a clear corneal incision.

50. The foldable Artiflex (Veryflex) lens is introduced vertically
with a special spatula through a clear corneal incision.

51. Blunt iris entrapment needles are used to create a fold of midperipheral iris
tissue
through vertical movement of the needle.

52. Complications
 Glare and haloes
 Anterior chamber inflammation/pigment dispersion
 Endothelial cell loss
 Glaucoma
 Iris atrophy or dislocation
 Cataract
 Hyphema, retinal detachment rarely

53. Poorly fixated Artisan lens with pseudophakodonesis
causingchronic uveitis

54. ciliary congestion

55. Artisan lens dislocation after blunt
trauma

56. After relocation

57. Posterior Chamber Phakic
IOL

58. Posterior Chamber Phakic
IOL
 Placed in the posterior chamber just in front of the
normal crystalline lenses.
 Materials:
 Silicone : PRL
 Collamer : ICL
 Hydrophilic acrylic : Sticklens

59. Properties desired in the IOL are:
 Allow permeability of nutrients
 Circulation of aqueous humor
 Not cause crystalline lens or zonular trauma.

60. Implantable Collamer Lens (ICL)
 In 1993, a posterior chamber phakic IOL made of
hydrophilic flexible material collamer, which is a
copolymer of HEMA (99%) and porcine collagen (1%),
was developed.
high
biocompatibil
ity and
permeability
to gas ,
metabolites
free space
left
between
the IOL
and the
crystalline
lens,
Avoid the
development
of cataracts.

61.  Available in powers from -2D to -20D and +1D to +10D.
 The toric version can correct upto 6D of astigmatism.
 Extremely thin with optic centre measuring in thickness
about 50 microns and the haptics 500-600 microns.
 Overall diameter varies between 11.5 to 13mm
 Sizing depends on the white-to-white measurement.

62. In December 2005, second phakic IOL was
approved by FDA.
The Visian ICL ( Implantable Collamer Lens)
 Approved for correction of –
 Myopia ranging from -3 to -20 D
 Astigmatism </= 2.5D
 Adults 21- 45 years of age with ACD of 3.0 mm or
greater and Shaffer grade II as determined by
gonioscopy.

63. Posterior chamber sulcus supported implantable contact
lens.

64. Silicone IOL
 The PRL( Phakic Refractive Lens) is a hydrophobic
silicone single-piece plate design IOL with a refractive
index of 1.46
 Mechanical touch, impermeability of nutrients, and
stagnation of aqueous flow without the elimination of
waste products  cataract formation
 Changes its vaulting to avoid this

65. Silicone IOL..cont..
 The new models (PRL-100 and 101 (myopia), and
PRL-200 (hyperopia), which are claimed to float in the
posterior chamber with its haptics resting on the
zonules,
 Decreased the incidence of cataract formation to
almost zero.
 But complications, such as lens decentration and
zonular dehiscence with dislocation of the lens into the
vitreous cavity.

66. Posterior chamber
phakic refractive lens
for myopia (top) and
hyperopia (bottom).

67. Procedure
 Mydriasis
 Topical or peribulbar anesthesia
 Temporal clear corneal tunnel
 Viscoelastic .
 Foldable IOL insertion into AC (with an injector or with
forceps)
 Check orientation
 Placement of footplates below iris
 Iridectomy
 Closure of incision

68. A posterior chamber lens is folded
(A) and inserted through a small
incision (B) with a forceps.

69. Iridotomies
 Both for iris clip and posterior chamber phakic IOLs
patent Iridotomies is an essential prerequisite.
 Done either 1 week before the surgery with the yag
laser or
 During surgery with scissors or using the vitrectomy
cutter.

70. Ideal sites for yag iridotomies prior to phakic IOL implant.

71. At the end of the procedure a peripheral iridectomy is
performed.

72. Complications
 Glare and haloes
 Cataract
 Pigmentary dispersion and elevated intraocular
pressure
 Decentration
 Endothelial cell damage

73. Glare and haloes
 Incidence 2.4-54.3%.
 The frequency of haloes
was higher when the ICL’s optical zone size was small.
 The rate of haloes correlated to the difference between
the scotopic pupil diameter and the optical zone size.

74. Cataract
 As a result of trauma to the crystalline lens during the
implantation procedure
 Due to long-term contact between the IOL and the
crystalline lens.
 Metabolic disturbances
 The majority of these cases were anterior subcapsular.
 Explantation of the ICL is easily
performed through the
same incision

75. Pigment Dispersion Syndrome
 Rubbing at the optic–haptic junction on the posterior
face of the iris  iris abrasion  release of pigments
into the aqueous humor.
 Pigment deposits had no visual consequences as they
were located at the optic–haptic junction rather than
the central optic.

76.  If PC phakic IOL is:
 Undersized  decreased vaulting  contact between
the IOL and the crystalline lens
 Too large  iris friction  pigmentary dispersion
 This is one important reason for adequately measuring
the sulcus-to-sulcus distance.

77. Pigmentary deposits are seen in the angle in an eye with a
posterior chamber phakic intraocular lens.

78. Decentration
 Since the PRL lens floats in the posterior chamber
with the haptics resting on the zonular apparatus,
 zonular erosion by the IOL haptics seems to be the
main mechanism for IOL instability and dislocation.

79. Bioptics
 The combination of phakic IOL implantation followed by
LASIK in patients with extreme myopia or hypermetropia
and high levels of astigmatism.
 When an anterior chamber phakic IOL is planned to be
combined with LASIK,
 Corneal flap created just prior to the insertion of the lens;
then, at a later time, usually after 1month, the flap is lifted for
laser correction of the residual ametropia.
 This two-step technique was called adjustable refractive
surgery (ARS) by Guell.

80.  The rationale in performing the flap first is to avoid any
possibility of contact between the endothelium and
the IOL during the suction and cut for the LASIK
procedure.

81. Conclusion
 The field of phakic IOLs has experienced tremendous
evolution in recent years.
 The increased knowledge on anterior segment
anatomy and availability of better imaging technologies
along with improved IOL designs and surgical
techniques have led to higher success rates with these
lenses.
 Compared to corneal refractive surgery , phakic IOLs
compete favorably for the correction of high
ametropias, with excellent predictability, efficacy, safety
and quality of vision.

82. Thank you