1) The document discusses the clinical management of aphakia and pseudophakia. It covers the causes, optics, symptoms and signs of aphakia as well as management options including spectacles, contact lenses, and intraocular lens implantation. 2) Management of pseudophakia involves correcting the refractive error after cataract surgery and lens implantation through intraocular lenses. Considerations for lens type and power calculations in adults and children are discussed. 3) Complications of the different management approaches are compared, noting advantages and disadvantages of contact lenses versus intraocular lens implantation. Refractive surgery techniques for correction of aphakia are also briefly mentioned.

1. Clinical Management of Aphakia
and Pseudophakia
Moderator: Presenters:
Niraj Dev Joshi Ashi Lakher
Rina chaudhary
21st Batch

2. Presentation Layout:
• Introduction to Aphakia
• Management modalities of aphakia
• Introduction to pseudophakia
• Management modalities of pseudophakia
• References

3. Introduction to Aphakia
• Aphakia, a term proposed by donders, is used to
indicate absence of crystalline lens from the dioptric
system of the eye.
• Lens is absent from pupillary plane and does not take
part in refraction.

4. Causes of aphakia:
• Congenital absence of lens
• Surgical aphakia
• Aphakia due to absorption of lens matter
• Traumatic extrusion of lens
• Posterior dislocation of lens
Optics of Aphakia:
• Eye becomes highly hypermetropic.
• Total power of eyes is reduced to about +44D from
+60D.

5. • Anterior focal point is 23.2mm in front of cornea.
• Posterior focal point is 31mm behind the cornea.

6. • Visual acuity in aphakia is falsified due to larger image
size i.e. Vision recorded is theoritically better than the
actual VA .
• There occurs a total loss of accommodation.
• In monocular aphakic children, the major hindrance
to development of binocular vision is aniseikonia of
30% due to anisometropia.

7. Symptoms:
• Marked defective vision for distance and near.
• Erythropsia and cynopsia
Signs:
• Anterior chamber deep than normal.
• Jet black pupil
• Iridodonesis i.e. tremulousness of iris.
• Purkinje’s image shows only two images.(3rd & 4th
Purkinje image absent)
• Fundus examination shows hypermetropic small
disc.

8. Management of Aphakia:
1.Spectacle
2.Contact lens
3. IOL
4.Refractive surgery.

9. 1.Spectacle:
• Optical principle is to correct the error by convex lens
of appropriate power.
• Spectacle has been most commonly employed
method to correct aphakia in past because it was
easy, safe and inexpensive.

10. • Disadvantages:
1.Increased retinal image size
2.Decreased field of view
3.Presence of ring scotoma
4.Increased occular rotation
5.Increased lens aberration
6.Motion of object in field of view
7.Appearance
8.Demand on convergence.

11. 1.Increased retinal image size:
• Retinal image size increases by 28%.
• Aphakic patient must adapt to new size- distance
relationship in his/her daily life.
• Familiar objects not only appear to be much larger
,they also appear to be much closer.

12. 2.Decreased field of view:
• The base to the center prismatic effect of high plus
lens reduces the size of the FOV through the lens.

13. • Aphakic patient suffer from more loss of macular
field of view -17 degree than peripheral field of
view-7 degree.

14. 3.Presence of ring scotoma:
• The base to center prismatic effect of a strong plus
lens causes an angular gap in object space completely
around the lens.
• As the eye rotates ,the scotoma moves hence the
term roving ring scotoma.

15. • The term Jack in the box phenomenon has been used
to describe the way an object seems to jump in and
out of the field of view as it moves out of and into the
ring scotoma.

16. 4.Increased occular rotation:
• The excursion of the eye increases for the plus lens
caused by presence of prismatic effect.
5.Increased lens aberration:
• For plus lenses aberration is quiet severe.
• Oblique astigmatism ad curvature of image can
affects patient visual acuity and contrast.
• Pin cushion distorsion can change in magnification
across the field of a lens.

17. 6.Motion of object in field of view:
• Swim ,occur when the eyes are held steady fixating
an object ,and the head moves to look at a object not
in direct view.
• There is a reverse motion ,caused by a prismatic
effect , with the base of the prism in the direction of
head movement.

18. 7.Appearance:
• Apparent enlargement behind bulbous , thick lens.
• Aphakic lenticular lens gives ‘’bull’s eye’’ or “fried egg
appearence.”
8.Demand on convergence:
• Convergence of the visual axis toward a near fixation
point creates a base out prismatic effect, when
reading must converge considerably more than that
for a low power wearer.

19. Consideration to be taken while
selecting lens:
• lens thickness: The centre thickness of plus lens can be
reduced by choosing a high refractive index material
and aspheric lens design.
• Lens weight: Use of plastic lenses and high index lens
material to reduce centre thickness.
• Lenticular lens design
• Smaller size of the spectacle frame (smaller size
reduces lens mass and thereby minimizes lens weight)

20. • Improving overall cosmesis
• Minimizing magnification by keeping the
vertex distance of the lens close to eyes and
using of flatter aspheric form lenses.
• Protection from glare and ultravoilet
radiations.

21. 2. Contact lens in Aphakia:
• Contact lenses are often used to provide optical
correction in instances of extreme refractive
error.
• Treatment of choice for
-those who are unsuitable for IOL implants
-those who have experienced a failed IOL implant
-pediatric aphakia
-unilateral aphakia

22. Advantages over spectacles:
• Image magnification is 7-8 %; usually tolerated by
patients.
• Increase in the visual field (both central and
peripheral)
• Less aberration
• BSV where fellow eye has useful vision
• Management of Post operative astigmatism
• Multiple options in CL vision correction
• Cosmetically well accepted.

23. Pre fitting procedure:
• Post surgical evaluation of ocular health
• Spectacle refraction
• BCVA to enable comparison with the contact lens
VA.
• Corneal topography assessment
• Determine pupil size ,shape ,and position.
• Examination of the eyelids
-tonus
-resting position
- closure completeness

24. Contact lens options in
Aphakia
• Hydrogel lenses
• Silicone hydrogel lenses
• RGP lenses
• Silicone elastomer
• Scleral lenses
• Tinted lenses
NOTE:
All contact lenses for aphakia must incorporate UV blocking
agents.
DW or EW contact lenses based on manual dexterity. EW is
best suited to poor lens handling patients

25. Hydrogel lenses:
• Can be fitted in cases with low astigmatism or
failed RGP lens wearer.
Advantages:
• Offer good initial comfort
• Less prone to displacement
• Offer good centration (with large diameter lens)
• Stable positioning of the optics over the eye
during the blinking and eye excursions
• Stabilize promptly after insertion

26. Disadvantages :
• Poorer oxygen transmission
• Aggravate existing dry eye problems
• Greater care and maintenance needs
• Higher overall costs
• Limited parameter available
• Handling can be more difficult
• May discolor with topical medications
• Uptake of preservatives

27. RGP lenses :
• Can be fitted in cases with higher corneal astigmatism
and corneal distorsion.
• Provide optimum vision (astigmatic correction)
• High DK/t
• Fewer eye complications
• Easier lens care
• Customized designs possible
• Curves and BVP can be modified

28. Aphakic RGP lens design

29. Single cut design
• The term “single cut” refers to a lens that has a single
radius of curvature on its front surface.
• Total diameter : chosen small to keep central thickness
minimum (7.5 to 8.5mm).
• Indications :
– Narrow palpebral aperture size
– steeper cornea
– No or little WTR astigmatism
– Tight lids

30. Lenticular RGP design
• Front surface lenticular design with minus carrier are
generally fitted to :
– Reduce the central thickness
– Increase the peripheral thickness to encourage lid
interaction and cause a higher riding position so that
the BOZD will be better centered over the pupil
The thinner design with minus carrier and larger TD
place the lens’ center of gravity more posteriorly and
prevent lens dropping to inferior lens margin

31. • Total diameter: >FOZD by 1.5 to 2mm to give sufficiently large
minus carrier (9 to 10.5mm)
• Larger TD increase comfort and reduce 3-9 o clock staining
• Posterior peripheral curve design:
• Mid periphery back surface curves should align with
cornea for stability
• Peripheral curves and widths should be chosen to give
optimum edge width(0.5mm) and clearance (90 to
120µm)

32. • Anterior peripheral curve design :
• Lenticular carrier radius design is dependent on
FOZD
• If too flat, lens periphery too thick, cause discomfort
Indications:
• larger palpebral aperture
• flatter corneas
• ATR astigmatism
• looser lids

33. Silicone elastomer:
• Can be fitted in cases of low astigmatism and
pediatric aphakia.
• High DK (>100) and relatively small TD (11.5mm)
• Increased modulus; easier to insert
• Surface coated to provide a hydrophilic surface for
good on-eye wettability.
Disadvantages :
• Lens adherence
• Deposit problem
• Expensive

34. Scleral lenses:
• Significant in corneal distorsion.
• Not commonly used because of cost.

35. Disadvantages of contact lens in aphakia :
• Foreign body sensation
• Corneal complications
• Lens spoilage
• Spectacles may be required over contact
lenses for reading
• High +Rx lenses more likely to decentered

36. IOL Implantation
• Presently,intraocular lens(IOL) implantation is
the method of choice for correcting aphakia.
• Replaces the crystalline lens.
• To correct the optical power of eyes following:
Cataract surgery
Refractive surgery

37. Primary vs Secondary Implantation
• Primary Implantation :
Implantation of IOL during cataract surgery.
• Secondary implantation :
Implantation of IOL to correct aphakia in
previously operated eye.

38. In Pediatric Cataract
• Difficult to implant IOL in congenital cataract
due to small size of eyeball.
• In unilateral cases,primary implantation is
indicated as soon as the pt is fit for
anaesthesia ,ideally between 2 and 3 months
of age.The earlier the surgery is done , the
better the chance that deep amblyopia can be
overcome.

39. • In case of unilateral congenital cataract most
studies suggested that surgery after 6 weeks
of life is less likely to result good visual acuity.
• In bilateral congenital cataract difference between
surgery of two eye must be less than 6 weeks.

40. Choice of lens and dioptric power in pediatric
pseudophakia
• In children <2 years Under-correcting biometry
by 20% or by using axial
length
In children 2-8 years under correcting biometry
by 10%
In children >8 years Same as adults
Dahan et al. J. Cataract Ref Surgery 1997;
23; 618-23
Paediatric Cataract Management- Part of
AIOS CME programme published 2012

41. Based on the method of fixation
1.Anterior chamber IOLs(ACIOLs)
2.Iris supported lenses
3.Posterior chamber IOLs(PCIOLs)
Ciliary sulcus fixated
In the bag fixated
Scleral fixated

42. 1.ACIOLs
• Lies entirely in front of iris and are supported in the
angle of anterior chamber.
• ACIOL can be inserted after intracapsular or
extracapsular cataract extraction.

43. 2.Iris supported lenses
• These lenses are fixed on the iris with
the help of sutures,loops or claws.
I. Prepupillary iris claw lenses
• These lenses are fixed/clawed in front of
iris
I. Retropupillary iris claw lenses
• Are fixed/clawed behind the iris
• Cosmetically,these are more acceptable
and it is very difficult to differentiate
these from PCIOLs

44. 3. PCIOLs
• Rest entirely behind the iris
• Supported by ciliary sulcus or
the capsular bag
In-the-bag fixated (ideal) Ciliary sulcus Fixated

45. Scleral fixated IOL : PCIOL sutured to
sclera through sulcus

46. IOL Calculations:
• Since 1975, IOL power has been calculated using accurate
measurement of an eye’s corneal power and axial length (AL).
• Power of the IOL was calculated using clinical history alone.
• Or the preoperative refractive error prior to cataract development.
• Today, the power of the lens implanted during cataract surgery can
be manipulated
• Even patients who are highly myopic or hyperopic can achieve a
near plano result after IOL implantation.

47. formulae
Theoretical
formulae
Regression
formulae
Mix of both
• Based on mathematic principles revolving
around the schematic eye.
• 1st generation
• 3rd & 4th generations
• Working backwards on post operative outcomes
• 2nd generation

48. Generations:
1st
1st
• SRK 1
• Binkhorst
formula
2nd
• SRK II
4th
4th
• Holladay 2
• Haigis
5th
• Hoffer H-5
3rd
3rd
• SRK/T
• Holladay
• Hoffer Q

49. SRK Formulae:
Where,
P= IOL power to be used (D)
A = IOL specific A constant
K = Average keratometry in diopters
L = Axial length of the eye (mm)

50. Range of axial length and Preferred formula:
Axial length (mm) Formula
< 20 mm Holladay II
20-22 mm Hoffer Q
22-24.5 mm SRK/T / Hoffer Q/Holladay (average)
> 24.5-26 mm Holladay I
> 26 mm SRK/T

51. Advantages of IOL implantation
• Little image magnification
• No spherical and prismatic aberration
• Minimum or no aniseikonia
• Normal peripheral field
• Cosmetically well accepted

52. Disadvantages of IOL implant
 Complications may occur such as:
• Mechanical damage to the IOL
• Dislocation
• Cystoid macular edema
• Anterior/posterior capsule opacification
• Calcium deposits within the optic of hydrophilic IOL
 Need of qualified surgeon and sophisticated
instruments
 Cost

53. Contact lens vs IOL
• A study suggests no statistically significant difference
in grating visual acuity at age 1 year between the IOL
and contact lens groups; however, additional
intraocular operations were performed more
frequently in the IOL group.
• 1.A randomized clinical trial comparing contact
lens with intraocular lens correction of
monocular aphakia during infancy: grating acuity
and adverse events at age 1 year.Infant Aphakia
Treatment Study Group; Arch Ophthalmol 2010
Jul;128(7):810-8. doi:
10.1001/archophthalmol.2010.101. Epub 2010

54. • Another study shows that infants' eyes had a similar rate of
refractive growth after unilateral cataract surgery whether an
IOL was implanted or aphakia was corrected with contact lens.
• However, A worse visual outcome was associated with a
higher rate of refractive growth in aphakic, but not
pseudophakic, eyes.2
• 2.Comparisonoftherateofrefractivegrowthinaphakiceyesversus
pseudophakiceyesintheInfantAphakiaTreatmentStudy;LambertSRet
al;JCataractRefractSurg.2016Dec;42(12):1768-1773.
doi:10.1016/j.jcrs.2016.09.021

55. Refractive surgery for Aphakia
• under trial for correction of aphakia
1. Keratophakia :
corneal tissue from a donor is frozen
, reshaped, and transplanted into the
corneal stroma of the recipient to
modify refractive error.
2. Epikeratophakia :
surgical procedure in which a donor cornea
is transplanted to the anterior surface of the
patient's cornea

56. 3. Hyperopic laser assisted in situ keratomileusis
• corrective eye surgery in which a flap of the
corneal surface is raised and a thin layer of
underlying tissue is removed using a laser

58. Pseudophakia
• The condition of aphakia when corrected with
implantation of an IOL
• a/k/a artiphakia

59. Signs of pseudophakia
• Surgical scar near the limbus
• Anterior chamber deep
• Mild iridodenesis

60. • Purkinje image test shows 4 images
• Blackish pupil with shining reflexes.
• Visual status and refraction varies

61. Changes in visual system in pseudophakia
• Visual acuity :improves because of removal of
cataract
• Colour vision:many researches found out improvement in
colour vision but B-Y defects were found in postoperative
retinal complications.
( Color vision in cataract, aphakia and pseudophakia , Marré M, Marré E,
Harrer S.Klin Monbl Augenheilkd. 1988 Mar;192(3):208-15. German)
• Contrast sensitivity : is decreased in pseudophakes as
compared to phakics but is better than spectacle wearing
aphakes.

62. • Accomodation : present if accomodating IOL is
used but absent if monofocal IOL is used.
• Stereoacuity : found to be improved to 40-80
sec of arc with random dot stereo test
(Graefe’s archive for cliical and experimental optometry, feb 2011, vol 249,
issue 2)

63. Refractive status of pseudophakic eye
emmetropia Consecutive myopia
consecutive hyperopia astigmatism

64. 1.Emmetropia :
• Exact IOL power
• Require near addition
2.Consecutive myopia :
• overcorrected IOL
• minus lenses for distance
• may or may not require near correction
3. Consecutive hyperopia :
• undercorrected IOL
• plus lens for distance
• additional plus for near

65. 4.Astigmatism :
• Pre existing astigmatism
• Incision length: larger incision (6-10mm) show ATR shift.
• Site of incision:
Incision located at superior limbus induces WTR astigmatism
Incision located temporally will induce ATR astigmatism
• Suture : sutures induce central steepening, or plus cylinder, in the
meridian placed.

66. Management for pseudophakia
• Spectacles
-single vision lenses
-bifocals
-progressive addition lenses
• Contact lens
• Refractive surgery

67. 1. spectacles
I. single vision lens
• Near single vision when
correct IOL implanted
• Different lenses for distance
and near in case of consecutive
myopia, hyperopia or astigmatism

68. 2. Bifocals :
• Different segment types available
i. Round segment
ii. D- segment (flat top)
iii. E-segment(executive)
iv. Ribbon segment

69. • For myopes, D-segment bifocal and executive
bifocal are best because they minimize image
jump and image displacement
• For hyperopes, Image displacement is lessened
with a round top lens. Although image jump will
be present, it is less disturbing than image
displacement
• Ribbon segments are good for someone who
requires distance vision below the bifocal area

70. Progressive addition lenses
Lens having continuous downward
transition of lens power from a stable
distance power in the upper portion of
the lens through a progressive zone to a
stable near vision portion in the lower
area of the lens

71. Contact lens options
• Combination of CLs (D) and spectacles (N)
• Monovision
Conventional monovision
Enhanced/Modified monovision
• Bifocals:
 simultaneous vision
 alternating vision (translating lens)

72. Refractive Surgery Options
• Monovision LASIK : fully correct the distance vision of one eye (usually
the dominant eye), and intentionally make the non-dominant eye mildly
nearsighted.
• Conductive keratoplasty : uses low-level, radio frequency
energy to shrink collagen fibers in the periphery of the cornea. This
steepens the central cornea, in effect lengthening a too-short eyeball and
provide more up-close focusing power
• Artificial Lenses (Refractive Lens Exchange or RLE):
surgical procedure, is becoming more popular because of the recent
availability of FDA approved multifocal or accommodating artificial lenses
capable of correcting presbyopia.

73. references