5.3.2. Chooses, fits and manages the correction of presbyopic patients.

Question 1

1. Simultaneous design (most MFs)

Answer 1

• Look through D & N rx at the same time
• Visual system learns to select the appropriate rx through the lens, depending on the object distance
  Concentric
• Can be centre near or centre distance
• Distance or near power is in the centre surrounded by concentric rings of N & D powers
  Aspheric
• Distance or near power is in centre, with a gradual transition to other powers as you move away from the centre (similar to varis)
• 1 day moist multifocal has an aspheric centre near design. The optical design varies to account for pupil size variation according to age and refractive error.

Question 2

2. Segmented/translating

Answer 2

• Like bifocal/trifocal specs
• D power is in the centre & upper zones
• N power is in the lower portion of the lens
• Bottom lens edge is flattened to keep lens from rotating
• Visible line
• Px switches between rx’s by looking up & down as in bifs
  *

Question 3

Multifocals – 1st choice advantages vs dissadvantages

Answer 3

Advantages

• Maintain binocular vision
• Can see all distances – D, I & N
• Opteyes – toric now available, up to 5.75

Disadvantages

• Compromised vision (any presbyopic CL is) – 6/7.5, N8
• No daily toric option
• 15-day adjustment period
• Px may experience aberrations/flare if pupil size is larger than optic zone

Question 4

Monovision

Answer 4

• 1 eye is corrected for distance & the other for near
• Visual system alternates central suppression when alternating between distance & near targets
• Causes slight reduction in DVA & non-significant reduction in NVA
• Establish ocular dominance using +2.00 test
• Dominant eye = distance correction as would normally prescribe for CLs (considering BVD / cyl)
• Non-dominant eye = near correction (distance correction would prescribe for this eye which incorporates px’s near add)
  *

Question 5

Monovision advantages vs disadvantages

Answer 5

Advantages

• Good for early presbyopia (problems for +2.00 upwards)
• Easy to fit (range of lens designs, materials & modalities)
• Reduced chair time
• Less costly for px’s

Disadvantages

• Reduced stereopsis & contrast – no binocular vision
• Glare when driving at night
• Adaptive period (developing suppression) – takes 1 week or so
• Limited intermediate vision
• Unsuitable for monocular px’s

Question 6

1-DAY ACUVUE® MOIST MULTIFOCAL

Answer 6

• Material: etafilcon A, silicon hydrogel
• Add: ADD LOW +0.75D to +1.25DMID +1.50D to +1.75DHIGH +2.00D to +2.50D
  • concentric design

Question 7

umere multifoca

Answer 7

• Third generation siliconehydrogel daily disposable lensesincorporating the right balanceof properties for health andcomfort, providing excellentvision at all distances.
• Power range:+5.00 to -6.00DS(0.25D steps)
• ADDs:LOW (up to +2.25)HIGH (+2.50 to +3.00)
• Dk/t (@-3.00DS): 86
• Base curve: 8.60mm
• Diameter: 14.1mm
• Water content: 56%
• Multifocaldesign: Centre near

Question 8

vusion multifocal

Answer 8

Daily disposable hydrogellenses with PC Technology™ tohelp with contact lens relateddryness, providing excellentvision at all distances.
Power range:+6.00 to -10.00DS(0.50D steps after -6.00DS)
ADDs:Single power profile up to +2.50
Dk/t (@-3.00DS): 28
Base curve: 8.70mm
Diameter: 14.2mm
Water content: 60%
Multifocaldesign: Centrenear

Question 9

opteyes multifocal

Answer 9

• Premium third generation reusable silicone hydrogel lenses combining key material and design elements to offer comfort and clear vision at all distances.
• Power range:+6.00 to -10.00DS(0.50D steps after -6.00DS)
• ADDs:+1.00, +1.50, +2.00, +2.50
• Dk/t (@-3.00DS): 142
• Base curve: 8.60mm
• Diameter: 14.0mm
• Water content: 48%
• Multifocaldesign: Centre distance and
• centre near

Question 10

lacrima multifocal

Answer 10

• Third generation reusable silicone hydrogel lenses incorporating the right balance of properties for health and comfort, supporting excellent vision at all distances.
• Power range:+6.00 to -8.00DS(0.50D steps after -6.00DS)
• ADDs:LOW (up to +2.25)HIGH (+2.50 to +3.00)
• Dk/t (@-3.00DS): 86
• Base curve: 8.70mm
• Diameter: 14.2mm
• Water content: 56%
• Multifocaldesign: Centre near

Question 11

vusion multifocal

Answer 11

• An extensive parameterrange and PC Technology™to maximise vision at alldistances and help keep lensescomfortable all day.
• Power range:+20.00 to -20.00DS(0.50D steps after -6.50 and +6.00DS)
• ADDs:+1.00, +1.50, +2.00, +2.50, +3.00,+3.50, +4.00
• Dk/t (@-3.00DS): Varies with RXBase curve: 8.70mm
• Diameter: 14.4mm
• Water content: 62%
• Multifocaldesign: Centre distance and centre near

Question 12

Pushing plus…

Answer 12

reduces the disparity between distance and near powers ,making it easier for the brain to adapt to multifocal optics. It means less accommodation is used making things more comfortable for the patient

Question 13

If you add power to the dominant…

Answer 13

check that the near vision is still OK & vice versa

Question 14

Presbyopic CLs advnatvages vs disadvnatages

Answer 14

* Advantages:
* Good quality of vision
* Suitable for px with BV problems – amblyopia, decompensating phoria, strong dominance
* Even possible for monocular patients
* Good stereo, CS and Binoc VA
* Disadvantages
* Expensive
* Less stable vision
* Difficult to fit
* Requires more chair time
* Lens interacts with lids – reducing comfort (RGP?)
* Some designs require px to have taut lower lid – reduces with age
* Adaptation required – risk of non-tolerance
* NV only on down gaze (RGP)
* Come in a limited range
*

Question 15

 Examples of Presbyopic CLs:

Answer 15

o CooperVision – Biofinity multifocal
o Acuve – Acuve Oasys Multifocal
o Alcon – Dailies Total Multifocal
o Alcon – Dailies Aqua Comfort Plus Multoifocal

Question 16

here are two types of Presbyopic lenses:

Answer 16

Alternating (translating)
Simultaneous (non-translating)
* Concentric
* Aspheric
* Diffractive

Question 17

Alternating designs

Answer 17

• These lenses have a near add on the bottom of the lens
• **The lens moves up when we look in the down gaze **
• There needs to be sufficient movement to ensure ¾ of the pupil is looking through the seg
• The segments are either fused or solid (made from one piece)
• They are usually RGPs
• The lens requires a stabilisation method:
• Either prism ballast or peri ballast
• As the lens moves on the eye, a taut lower lid is essential
• Lower lid should be no lower than inferior limbus, to support lens
• There should be very little movement of the lens upon blinking
• Due to the lid interaction, comfort is reduced
  *

Question 18

Simultaneous Designs

Answer 18

• These are more common
• They correct for d and n together
• They don’t rely on lens movement
• A multifocal isn’t a varifocal – it has multiple focal point, but not necessarily progression
• Pupil size is key in fitting these lenses
• The pupil is largest in: dim conditions, early presbyopes and myopes
• The pupil is smallest in: bright conditions, late presbyopes and hyperopes
• These lenses can induce spherical aberrations as paraxial rays are focused on the retina & coaxial focussed in front/behind – hence pupil size is important to block these paraxial rays
• There are three types: concentric, Aspheric and Diffractive

Question 19

Concentric

Answer 19

• They can either be centre-distance or centre-near lenses
• They have a centre-surround design
• The centre has a focal length, and the periphery has one, or many zones of another focal length (s)

Question 20

Bi-concentric

Answer 20

 C-D lens:
o Will correct DV with the centre of the lens and the periphery of the lens will correct for NV
o Low illumination (dilated pupil) favours NV
o High illumination (small pupil) favours DV
o Due to senile miosis, NV suffers
o If reading outside, recommend sun spec – without sun specs for outside reading, they will constrict pupils and look through distance portion
** C-N lens **
o Will correct for NV using the centre of the lens, and the periphery will correct the DV
o Low illumination (dilated pupil) favours DV
o High illumination (small pupil) favours NV
o Due to senile miosis, DV will suffer
o If driving, recommend sun specs – we don’t want them to constrict pupils from sunlight and start looking through near when driving

Question 21

Multi-zone concentric

Answer 21

 These lenses don’t rely on the size of the pupil. They project 2 different images and don’t depend on you looking through a certain portion.
 The width and spacing of each zone are based on the variation of pupil under different illumination
 These lenses are designed to favour DV in high and low illuminations
 But there is an equal ratio of NV and DV in ambient in illumination

Question 22

Advantages vs disadvantages of concentric

Answer 22

Advantages of concentric
 They perform better than other simultaneous designs with high contrast targets
 Lenses can rotate freely without consequence
Disadvantages of concentric
 Reduced CS and VA due to suppression of blurred image
 Perform poorer than other simultaneous designs with low contrast targets
 Decentration may lead to asymmetry and blur – coma aberration – ghosting effects

Question 23

Aspheric

Answer 23

 This design involves a continuous change in power from the centre to the periphery
 The effective near add depends on the rate of change in asphericity
 Provide some form of intermediate vision
 They come in C-D and C-N
 Advantages:
o Some degree of intermediate vision
o Can rotate freely without consequence
 Disadvantage
o They are pupil size dependent

Question 24

Simultaneous design advantages vs disadvantages

Answer 24

Simultaneous design advantages
 Not gaze dependent
 Comfortable
 Easy to fit
 Suitable for enhanced monovision
 EW options
 Multiple add sizes
Disadvantages
 Small pupils less suitable
 Reduces CS
 Illumination dependent
 Visual compromise difficult for some
 Add size limited

Question 25

Common problems

Answer 25

* Most common problem is poor vision * History – establish when/where vision is poor * VA - Have realistic aims * OR – allow 20 minutes for neural adaptation. Use the 6/9 line and make small 0.25D changes. Do this for N and D. let the px trial it for a week. May need multiple trial periods * Management – we try and manage the px expectations * Always follow the manufacturers fitting guide, but as a rule of thumb: - To improve DV, reduce add by 0.25 steps in dominant eye.; Also try -0.25 binoc, check NV; try monoc -0.25 if NV suffers - To improve NV, increase ad by 0.25steps in non-dominant eye; Also try +0.25 binoc, check DV; try monoc +0.25 if DV suffers - Always consider astigmatism and BVD

Question 26

The aging eye Consider:

Answer 26

 Lid tension  Pinguecula/pterygium  Lenticular opacities  Macular changes  Tear film  Systemic pathologies – diabetes  Meds  Dexterity issues

Question 27

Monovision:

Answer 27

- Try to push plus in dominant eye & minus in non dominant eye. This will reduce disparity between retinal images if add is a little high - Find dominant eye. - If they go from non presbyope to presbyope and they already wear lenses, you can stick to same lenses - For intermediate - not possible, no depth perception as you can’t do distance & near at the same time

Question 28

Partial monovision:

Answer 28

- +0.50-0.75 for int tasks. Can give reading spex OTT for prolonged tasks. - Good for early presbyopes

Question 29

Enhanced monovision

Answer 29

- SV + MF combined! - Enhance DV - SVD to dominant, CN MF to non-dominant - Enhance NV - SVN to non-dominant, CD MF to dominant - Distance will always be dominant eye

Question 30

RGP MF Fitting:

Answer 30

- Alternating - near add bottom of lens. Segment either fused (not one piece) or solid (one piece). Requires stabilisation like prism or peri ballast. - You look down & lens moves up to put near into focus. At least 3/4 of the pupil should look through the seg. - Taut lower lid needed due to lens movement - MUST be no lower than inferior limbus! - Should be little movement on blink - Reduced comfort due to lid interaction, Expensive, RGP only. But…good vision - ML92 Maxim MF Aspheric lens better choice. Add of up to +4.00! -25.00 to +25.00D!! This is empirical fitting - Or just do monovision or SV with readers!