CLM - Soft Contact Lenses - Week 4

Question 1

Does Australia have a high or low proportion of RGP lens fits?

Answer 1

Lo

Question 2

hat is the most popular modality of contact lenses world wide?

Answer 2

Soft

Question 3

Do contact lenses have a short or long adaptation period?

Answer 3

Short

Question 4

Do soft contact lenses induce corneal distortion?

Answer 4

Minimally

Question 5

Do soft contact lenses cause spectacle blur?

Answer 5

Minimally

Question 6

Do soft contact lenses have high or low on-eye stability?

Answer 6

High

Question 7

Do soft contact lenses have a large or small optic zone? What does this mean for flare?

Answer 7

Large optic zone, giving minimal flare

Question 8

Is aniseikonia larger or smaller with soft contact lenses compared to spectacles?

Answer 8

Reduced aniseikonia

Question 9

Are anisometropic prescriptions more or less tolerated with soft contact lenses compared to spectacles?

Answer 9

Improved tolerance

Question 10

Are soft contact lenses easy to replace?

Answer 10

yesd

Question 11

Do soft contact lenses have a high or low risk of foreign body entrapment?

Answer 11

Low

Question 12

Are soft contact lenses appropriate for high degrees of astigmatism?

Answer 12

Limited application

Question 13

Are soft contact lenses suitable for irregular corneas like keratoconus or trauma?

Answer 13

May not be suitable

Question 14

Compare the incidence of corneal inflammatory and infective events of soft contact lenses with RGP lenses.

Answer 14

Higher incidence

Question 15

Are soft contact lenses durable?

Answer 15

Relatively low durability compared to RGP lenses

Question 16

What deposits are soft contact lenses prone to (3)?

Answer 16

Protein
Mineral
Lipid

Question 17

How often were conventional contact lenses replaced? What is the deadline? How long could they last?

Answer 17

Generally replaced in 6 month intervals
Should at least be replaced annually
Could last for 3+ years

Question 18

How does the lens cost of conventional contact lenses compare with disposable soft contact lenses?

Answer 18

The lens itself is lower cost, but with care systems, it is more expensive

Question 19

Do conventional contact lenses have a higher or lower overall rate of adverse reactions compared to disposable lenses?

Answer 19

Higher

Question 20

Do conventional contact lenses have higher or lower oxygen permeability compared to soft contact lenses?

Answer 20

Lower

Question 21

Are conventional contact lenses common?

Answer 21

No

Question 22

List 4 reasons why regular lens replacements are important.

Answer 22

Minimise the effect of lens deterioration and deposition
Assists with compliance
Detect changes in refraction

Question 23

What is the most common contact lens modality?

Answer 23

Disposable

Question 24

List 4 advantages of disposable soft contact lenses.

Answer 24

Improved ocular health
Reduced deposits
Thinner lens profiles
Patient convenience

Question 25

What is the benefit of maintaining an inventory of disposable soft contact lenses in practice?

Answer 25

Allows easy trial of the correct BVP

Question 26

Do disposable soft contact lenses have a narrow or wide range of parameters?

Answer 26

Wide

Question 27

List 4 disadvantages of disposable soft contact lenses.

Answer 27

Most parameters are available, but some are not Lens may sometimes rip in their packets Occasional patient perception of higher cost Patient attitude towards disposability

Question 28

What is the most common form of replacement schedules for disposable soft contact lenses?

Answer 28

Dailies (increasing trend)

Question 29

List 4 advantages of a daily replacement schedule for soft contact lenses.

Answer 29

Reduced potential for contamination No cost/inconvenience of storage/solution Minimal risk of physiological complications Maximum comfort and vision due to no accumulation of deposits

Question 30

Which replacement schedule for soft contact lenses has the lowest incidence of non-severe keratitis?

Answer 30

Dailies

Question 31

How do the replacement schedules for soft contact lenses compare for the risk of microbial keratitis?

Answer 31

Some studies have not found any lower risk among specific schedules (they had similar risks)

Question 32

What is the general consensus on the replacement schedules for soft contact lenses?

Answer 32

Dailies have the least complications

Question 33

Compare the cost of dailies to the other replacement schedules.

Answer 33

Dailies cost more

Question 34

Compare the parameters of dailies to the other replacement schedules.

Answer 34

More limited parameters, including for astigmatism and presbyopia

Question 35

What is the base curve of daily contact lenses like and why does this matter?

Answer 35

Often only have one base curve | Not good for steep or flat corneas

Question 36

Are dryness symptoms more or less in 2 week contact lenses vs 4 week contact lenses?

Answer 36

Fewer

Question 37

What generally happens to wearing comfort and vision quality with monthly contact lenses? How do the most recent SiH contact lenses compare?

Answer 37

A general decrease in both | SiH lenses were found not to differ significantly between 2 week and monthly

Question 38

List the following by compliance rate (highest to lowest): Fortnightly Monthly Dailies

Answer 38

Dailies Monthly Fortnightly

Question 39

List three primary reasons for replacement non-compliance.

Answer 39

Forgetting which day to replace Save money Running out of lenses (DD)

Question 40

What is generally the handling tint density for soft contact lenses? Does it have any cosmetic effect on the eye?

Answer 40

10% density | No cosmetic effect on the eye

Question 41

In what two refractive errors is handling tint especially recommended and why?

Answer 41

Hyperopes and presbyopes who have near focussing difficulties

Question 42

Aside from handling tint, list three other useful tints for soft contact lenses.

Answer 42

Enhancement tint Opaque tint UV blocking

Question 43

What are enhancement tints and over what diameter are they tinted?

Answer 43

Can modify the apparent iris colour | Tinted over a diameter equal to the HVID

Question 44

Are enhancement tint colours additive?

Answer 44

Yes

Question 45

What are opaque tints and what effect do they have on visual field sensitivity?

Answer 45

Changes iris colour and is opaque | Visual field sensitivity is slightly reduced (<1dB)

Question 46

How does the comfort of lenses with an opaque tint compare to those without?

Answer 46

Slightly reduced comfort due to surface irregularties where the tint is

Question 47

Give an example of a non-cosmetic use for opaque tinted soft contact lenses.

Answer 47

A blind eye with a damaged or irregular pupil or damaged iris

Question 48

What percentage of UV light can UV blocking lenses absorb up to?

Answer 48

Up to 90%