Year 1

Question 1

Common ocular conditions that can affect CL wear suitability

Answer 1

Corneal staining
Papillary conjunctivitis
Blepharitis
Meibomian gland dysfunction
Dry eye

Question 2

Blepharitis symptoms

Answer 2

Hard, brittle scales around base of eyelashes
Inflammation of eyelids

Question 3

Blepharitis causes

Answer 3

Bacterial toxins
Eyelash mites
Allergic reactions to bacteria

Question 4

Meibomian gland dysfunction risk on CL wear

Answer 4

Affects stability of tear film, CL wetting and comfort

*the glands which produce the outermost lipid layer of the tear film (reduce evaporation) are blocked

Question 5

Dry eye effects on CL wear

Answer 5

Affects stability of tear film, CL wetting & comfort

Question 6

Horizontal Visible Iris Diameter range (HVID) and avg

Answer 6

Range 10-14mm
Avg 11.8 mm

Question 7

Horizontal Visible Iris Diameter range (HVID) definition

Answer 7

distance between nasal and tenporal limbus
ie horizontal limbus diameter

Question 8

Soft CL advantages

Answer 8

Good initial comfort
Straightforward to fit
Easy to change prescription
Good for both full time or occasional wear

Question 9

Soft CL disadvantages

Answer 9

Higher risk of complications & infection compared to RGP
Readily available
Not customizable

Question 10

Rigid Gas Permeable CL advantages

Answer 10

Rigid lens surface offers better quality of vision
Reduced risk of infections and complications
Fully customizable
Good value for money as lenses are typically replaced every year or longer

Question 11

RGP CL disadvantages

Answer 11

Longer fitting process- lenses need to be individually manufactured
Longer time to adapt and reduce corneal sensitivity
High initial cost
Not for contact sports/ dusty environments
Must be worn on FT basis
Require careful cleaning

Question 12

Daily disposable CL advantages

Answer 12

Cost effective when worn <3 days a week
Ideal for infrequent wear
Minimal lens care required
Lower risk of infections due to constant replacement

Question 13

Daily disposable CL disadvantages

Answer 13

Expensive if worn on a full time basis
Higher environmental impact
Limited parameter range compared to other lens types

Question 14

Monthly CL lenses advantages

Answer 14

Cheaper that dailies if frequently worn >4 days a week
Larger range of parameters
Lower environmental impact

Question 15

Monthly CL lenses disadvantages

Answer 15

Inconvenient, hassles of cleaning lenses and lens care
Greater buildup of lens deposits
Higher risk of infections

Question 16

Silicone hydrogel advantages

Answer 16

Greater oxygen permeability- suitable for greater wearing times
Reduced risk of complications
Reduced on-eye dehydration- better for px with dry eye
New gen materials have a lower modulus- more flexible and comfortable

Question 17

Silicone hydrogel disadvantages

Answer 17

More exoensive than HEMA
Higher risk of corneal inflammatory events
Increased lipid deposits
Highere modulus- (first gen) mechanical complications and less comfortable

Question 18

Conventional hydrogel (HEMA) disadvantages

Answer 18

Lower oxygen permeability
Greater dehydration tendencies
Not suitable for long wearing times
Hypoxia- omplications from insufficient corneal oxygen supply

Question 19

Conventional hydrogel (HEMA) advantages

Answer 19

Lower deposition rate
Lower modulus- increased comfort
Cheaper than SiH
Lower risk of corneal inflammatory events (CIEs)

Question 20

Protein and lipid deposition is more common in which lens types

Answer 20

Protein- hydrogel
Lipid- Silicone hydrogel

Question 21

Modulus of a lens definition

Answer 21

Stiffness or rigidity

Higher modulus= stiffer lens

Question 22

Coefficient of friction definition

Answer 22

Level of resistance the upper lid will have when passing over the CL surface when blinking

*low coefficient= high lubricity= less irritation