Presbyopia Correction - Dr James Beatty

1. Presbyopia
correction
2011
Dr James Beatty

2. The Answer?

3. Why is it
important?
• 1.3 billion presbyopes world wide
• Like death and taxes it is relentless and
predictable
• Cost implications
• Productivity and functional implications

4. Why is it important?
• “Baby boomers”
– Generation with high expectations
– High levels of activity
– Do not want to accept limitations with vision

5. Anatomy of Accommodation: the ciliary muscle

6. Accommodation according to Helmholtz
• Ciliary muscle contracts ant lens becomes
more convex due to slackening of zonules

7. Accommodation according to Schachar
• Directly contrasts Helmholtz
• Zonular tension is increased- rather than
decreased- with ciliary body contraction

8. Accommodation
Accommodated o
Unaccommodated
Ciliary
muscle

9. Amplitude of accommodation
- From 1 mth old.
- More regular by 2-3 mths.
- Almost adult-like by 6 mths.
- Falls from maximum of 18D at 10yrs
- To zero by 70 yrs

10. 24
22
20
18
16
14
12
10
8
6
4
2
0
0 10 20 30 40 50 60 70 80 90
Age (yrs)

11. Young Old
Increased sclerosis of lens leads to loss of flexibility
and inability to change shape
Presbyopia: the common view

12. ….
embryologically
the lens is derived from
surface ectoderm…..
…and keeps growing
throughout life!

15. Treatment options
1784 Benjamin Franklin

16. Treatment options
• Glasses and contact lenses
– Still no.1
– Recent technological innovations vaulted
management of presbyopia into the surgical
arena
– Internet has educated patients
– Advise patients on options
– Can enhance your practice

17. Treatment options
• Surgery
– Corneal based surgery
• Laser correction (lasik)
• Conductive keratoplasty
• Corneal inlays
– Scleral expansion and anterior ciliary sclerotomy
– Lens based surgery
• Mulitfocal intraocular lenses
• Accommodating intraocular lenses

18. Monovision
• Well established
presbyopia therapy
• Achieved through
contact lenses or
surgically at the
corneal or lenticular
plane.

19. Monovision
• Mild myopia –0.5 to –1.5D in non-
dominant eye (avoid anisometropia no more
than 2D diff between the eyes)
• Need to be able to suppress blurred image
• Only a mild decrease in distance, good
stereo, very good intermediate

20. Monovision
• Not for patients with high visual
requirements for near or distance
• Glasses for driving or detailed near tasks
• Monovision with contact lenses success rate
of 80%
• Monovision excimer laser ablation with
lasik or PRK still the most commonly
performed surgical correction of presbyopia

21. Corneal based surgery
• Lasik
• Conductive keratoplasty
• Corneal inlays

22. Lasik
• Creating a multi-focal cornea
• Various possible ablation patterns
– Central near, midperiphery distance
– Inferior near, rest distance
– Central distance intermediate near
• Data limited but so far good
• Often compromises distance vision
• Induce abberations

23. Lasik

24. Conductive keratoplasty

25. Conductive
keratoplasty
• Probe delivers radiofrequency energy to the
cornea that heats up the collagen and causes it to
shrink
• Performed in the midperiphery with resultant
corneal flattening and central steepening
• Amt. of steepening depends on the no. of spots
and the no. of rings
• Non-dominant eye corrected for near(monovision)

26. Conductive keratoplasty

27. Conductive keratoplasty
• Safe and easy to perform
• Can only be performed on emmetropes and
hypermetropes
• Less popular because prone to slow
regression towards hyperopia
• Corneal scaring
• Unpredictable

28. Corneal inlays

29. Corneal inlays
• Biocompatible device placed in a pocket
created with a microkeratome or intralase
flap
• Designed for use in emmetropic
or hypermetropic eyes
• Aperture 1.6mm, outer rim 3.8mm
• Pin hole effect increases depth of focus
• Micro pores for nutrients

30. Corneal inlays

31. Scleral surgery
• Scleral expansion
• Anterior ciliary sclerotomy

32. Scleral surgery
• Objective of increasing zonular tension by
weakening or altering the sclera over the
CB in order to allow for passive expansion
• Based on Schachar
theory

33. Doesn’t work, therefore theory probably
wrong

34. Scleral surgery

35. Lens based surgery
• Multifocal intraocular lenses
• Accommodating intraocular lenses

36. Presbyopic correcting IOL’s
• Because of recent advances in lens
technology the future of presbyopia
correction is rapidly moving towards lens-
based surgical options
• Multiple designs by different companies
• Goal is to minimize the dependence on
spectacles or contact lenses after cataract or
clear lens surgery

37. Multifocal IOL design
• Multiple- zone IOLs ; 3 zones
• Central and outer for distance ( distance for large and small
pupils )
• Inner annulus for near ( near for moderately small pupils )

38. • Diffractive multifocal IOL :
• Uses geometric optics and diffraction optics
• Overall spherical shape of anterior surface produces image for
distance vision
• Posterior surface has stepped structure (like Fresnel prism)
• Diffraction from these multiple rings produces a second image
with an effective add

39. Presbyopic correcting IOL’s
• By design all of these lenses present more
than one image to the retina at the same
time
• This leads to reduction in contrast
• Abberrations such as glare and halos
• Pupil size may be an issue

40. Presbyopic correcting IOL’s
• Array(AMO)
– 50% glare and halos
• Rezoom(AMO)
– smoothing over zones
– light dependent
– poor intermediate

41. Presbyopic correcting IOL’s
• Technis(AMO)
– aspheric, diffractive
– poor intermediate
• Restore(Alcon)
– diffractive, aspheric
– +4 and +3

42. Presbyopic correcting IOL’s

43. Rezoom

44. Technis

45. Restor

46. Restor

47. Accommodating IOL’s
• Ideal accommodating lens would mimic a
juvenile lens that changes in shape and
dioptic power when the ciliary muscle
contracts

48. Accommodating IOL’s
• Lens refilling
– Surgical technique
– Material (volume and shape)
– Optics
– PCO
• Lens softening
• IOL that moves in the bag

49. Accommodating IOL’s
• Potential to correct near,
intermediate and distance
without glasses
• Potentially less side
effects
• Designed to sit posteriorly
in the bag
• With contraction of the
ciliary muscle the lens
shifts anteriorly allowing
“accommodation”

50. Accommodating IOL’s
• Mechanism – has hinges at the lens-haptic
juncture
• There is only one focal length but it shifts
• 1D power generated for near
• Increased depth of focus due to it’s posterior
positioning
• There is a learning curve, the patient needs to
learn how to accommodate with this lens in place

51. Crystal lens

52. Crystal lens

53. Crystal lens

54. • Patient walks into your office, wants to
know if they are a candidate for this type of
surgery

55. Patient expectations
• Excellent vision
• Immediate results
• Pain free
• Without side effects
• Do not want to get older

56. Patient discussions
• Expectations
• Alternatives
• Financial implications
• Side effects
• Bilateral need for surgery
• Neuro adaptation – may take months

57. Patient selection
• Pre-operative exclusion criteria
– Hypercritical patients
– Patients with unrealistic expectations
– Occupational - night drivers, pilots
– Unmotivated patients

58. Patient selection
• Pre-operative exclusion criteria
– No eye pathology
– Excelent visual potential
– Astigmatism <1.5D (Toric IOL’s, LRI’s)
– Presbyopic hypermetropes do the best

59. Pre operative evaluations
• Meticulous biometry measurements
required
• IOL Master
• Immersion ultrasonography
• Topographic analysis/ multiple keratometry
readings
• Multiple IOL formulas

60. Post operative considerations
• Astigmatism
• Post capsule opacities - yag
• Glare and halos - brimonidine
• Neural adaptation - 6months
• Enhancement
• Explantation

61. Discussion
• 10% of cataract surgery in the USA is now
done with multifocal lenses
• Large studies have shown that 45 % of
patients still use glasses (near, distance,
computer, driving)
• Light adjustable lenses

62. Thanks