dry eye and contact lens wear

Question 1

What is the pre lens tear film (PLTF)?

Answer 1

Tear film that sits above the lens and is associated with comfort

Question 2

Does the pre lens tear film protect against deposits?

Answer 2

Yes

Question 3

What is the post-lens tear film (PoLTF)? + what is it associated with?

Answer 3

Under the cls, associated with fit + lubrication + movement

Question 4

What layer of the tear film does a cl sit in?

Answer 4

Aqueous layer

Question 5

Is a PLTF always present?

Answer 5

No

Question 6

Why is tear exchange important?

Answer 6

To remove debris + metabolic waste products

Question 7

What are three effects a cl has on tear film?

Answer 7

• Tear film instability + evaporation (this is sue to wetability)
• Tear film mucins, electrolytes + increased osmolarity
• blinking

Question 8

What does reduced mucin lead to?

Answer 8

More friction

Question 9

What will happen to vision due to an unstable tear film?

Answer 9

Vision may fluctuate

Question 10

Is a higher or lower osmolarity associated with dry eyes?

Answer 10

Higher

Question 11

If a px has contact lens associated dry eyes (CLDE), what may you see on glands?

Answer 11

• secretions (MGD)
• Expression
• blockages

Question 12

If a px has contact lens associated dry eyes (CLDE), What should you examine in relation to lids and lashes?

Answer 12

• disease
• lid position
• blink rate

Question 13

If a px has contact lens associated dry eyes (CLDE), What should you examine in relation to ocular surface?

Answer 13

• staining
• inflammation
• redness

Question 14

If a px has contact lens associated dry eyes (CLDE), What should you examine in relation to tears?

Answer 14

• tear prism height
• TBUT
• quality
• osmolarity

Question 15

What are three ways to assess tear volume ?

Answer 15

• phenol red thread test
• schrimer
• tear scope

Question 16

How do you measure NIBUT?

Answer 16

Using a keratometer

Question 17

Describe the phenol red thread test.

Answer 17

• thread impregnated with phenol red
• colour changes from yellow to red
• thread hangs 1/3 from lateral canthus
• CANNOT touch cornea
• record after 15s

Question 18

What result will indicate dry eye with the phenol red thread test?

Answer 18

<9mm

Question 19

How long does schirmer test take ?

Answer 19

5 mins

Question 20

What is a disadvantage of the schirmer test?

Answer 20

Strips can feel uncomfortable= stimulate tearing reflex

Question 21

How does the tearscope work?

Answer 21

• diffuse white reflection over whole cornea
• lipid layer can be assessed
• patterns can be observed
• inserts can be placed to asses corneal distortion + damage

Question 22

What patterns can be observed with a tear scope? (There are 5)

Answer 22

• open meshwork
• closed meshwork
• wave
• amorphous
• colour fringes

Question 23

What are another four instruments can assess tears?

Answer 23

• Oculus Keratograph 5M
• Lipview
• InflammaDry
• TearLab- tear osmolarity

Question 24

What is an Oculus Keratograph 5M?

Answer 24

Topographer

Question 25

What can Oculus Keratograph 5M assess?

Answer 25

- MGD - Non-invasive TBUT - Tear meniscus - Lipid layeR

Question 26

What can does Lipview do?

Answer 26

Measures lipid layer + MG imaging

Question 27

What does InflammaDry do?

Answer 27

Detect inflammatory marker of DED. Takes 10 mins to do

Question 28

What reading on a TearLab-tear osmolarity will indicate abnormality?

Answer 28

>300mOsm/L

Question 29

Why does the lid epithelium change with CLRDE (contact-lens related dry eye)?

Answer 29

Due to friction- this friction is caused a thin tear film between ocular surface and lid wiper

Question 30

What is lid wiper epitheliopathy?

Answer 30

disruption to the surface epithelium of the lid wiper

Question 31

What is the lid wiper?

Answer 31

Area of epithelium in contact with the cls and wipes across the cl/eye

Question 32

How can you observe lid wiper epitheliopathy?

Answer 32

Evert lids + staining with lissamine green

Question 33

What is lid parallel conjunctival fold (LIPCOF)?

Answer 33

Breakdown in elastic fibres in loose conjunctiva

Question 34

What causes LIPCOF?

Answer 34

Ageing or mechanical forces between conjunctiva and lower lid

Question 35

What other signs may you see with LIPCOF?

Answer 35

Tear deficiency and inflammation of the conjunctiva

Question 36

How is LIPCOF graded?

Answer 36

By number and height of folds

Question 37

How can LIPCOF be managed?

Answer 37

- change lens type - change wearing schedule - manage tear quality issues - consider rewetting drop

Question 38

What is MGD?

Answer 38

Blocked meibomian glands

Question 39

What are two types of dry eye?

Answer 39

Evaporative and aqueous deficient dry eye

Question 40

Do the two types of dry eye have the same management?

Answer 40

No

Question 41

What is computer vision syndrome? CVS

Answer 41

prolonged screen use --> reduced blink rate/incomplete blinks --> eye discomfort or visual discomfort

Question 42

What are some sx someone with CVS may complain of?

Answer 42

- dry eye - eye strain - HAs - blurred vision - neck and shoulder pain

Question 43

What is the average blink rate?

Answer 43

12 blinks per min

Question 44

When reading what may the blink rate drop to?

Answer 44

4.5 blinks per min

Question 45

What does a reduced blink rate result in?

Answer 45

Tear film is replenished less frequently and evaporates quicker —> leads to ocular discomfort

Question 46

What are some solutions to a reduced blink rate?

Answer 46

- blinking exercises - 20-20-20 rule

Question 47

How should you manage dry eye in practice ?

Answer 47

- lens change - changes to environment - eye drops - lid hygiene - warm compress - diet

Question 48

What changes to environment can you do for dry eyes?

Answer 48

AC not directed in the face in the car as lower humidity = increased evaporation

Question 49

What does eye drops do for dry eye?

Answer 49

Immediate relief, more viscous agent = better for end of day as it can effect Vision

Question 50

What must you check with the eye drops?

Answer 50

That they are compatible for cls + preservative free

Question 51

What advice can you give to someone to manage MGD?

Answer 51

Warm compress for 10 mins twice a day

Question 52

Before manage dry eye, what must you do?

Answer 52

Identify the cause

Question 53

In terms of environment, what can contact lens discomfit be increased by?

Answer 53

- low humidity - increased air flow - computer use

Question 54

What diet info can you give to patients with dry eyes?

Answer 54

Take essential fatty acids such as omega 3 and omega 6 rich foods such as avocado, tuna ect

Question 55

Why should px take essential fatty acids?

Answer 55

The body cannot make them, it will help to enhance the lipid layer by reducing evaporation

Question 56

Can too much consumption of omega 6 negate the effects of omega 3?

Answer 56

Yes- balance is key

Question 57

Should you recommend ur px to drink more water for dry eyes?

Answer 57

You can do but few studies have looked into this , you can tell them to limit alcohol and caffeine consumption

Question 58

What is viscosity?

Answer 58

Fluids internal resistance to flow

Question 59

What does a high viscous agent aim to do?

Answer 59

- increase retention time - reduce friction - soothe irritated membranes

Question 60

What lid hygiene tips can you give to someone with dry eyes and bleph?

Answer 60

- clean lid margins x2 a day while condition bad and then can be decreased to x1 a day - clean with lid cleaning solution - avoid makeup on eyes

Question 61

How would you find out which dry eye they?

Answer 61

Through h&s + anterior eye assessment

Question 62

Should you follow up a dry eye px ?

Answer 62

Yes- book a follow up or phone call