Assess Tear Film

Question 1

list 5 methods for assessing the tear film

Answer 1

• volume: tear meniscus
• staining: sodium fluorescein
• tearscope: interference fringes
• shirmer test
• phenol red thread test

Question 2

what does the tear meniscus height assess

Answer 2

the volume of the tear film by assessing the reservoir of the tears by checking the height and regularity

Question 3

list the steps of how to assess the tear meniscus height

what is the average height

what is classed as dry eye

Answer 3

• 25x mag
• slightly dim illumination (less tearing)
• measure edge of lower lid to top of reflection
• average: 0.3mm
• dry eye: less than 0.2mm

Question 4

what does staining with sodium fluorescein assess and how does it do this

what is classed as dry eye

Answer 4

the tear film stability and TBUT

using a yellow dye that fluoresces green with blue light, the yellow filter removes the blue light coming back into our eye

less than 10 secs = tear film deficinacy

Question 5

what else can be used to measure TBUT other than fluorescein

Answer 5

keratometry mires (non invasive)

Question 6

what does the tearscope use in order for us to assess the tear film

Answer 6

interference fringes

Question 7

list the steps of how the schirmer test is carried out to assess the tear film

what is classed as dry eye

Answer 7

• anaesthesia is instilled 5 mins before the test
• a paper fold is inserted 1/3 from the lateral canthus
• px is to close their eyes for 5 mins before removing the paper
• less than 10mm = dry eye

Question 8

list the steps od how the phenol red thread test is carried out to assess the tear film

what is classed as dry eye

Answer 8

• insert the thread 1/3 from the lateral canthus
• measure the red part of the thread
• less than 10mm - dry eye

Question 9

name a difference between the schirmer test and the phenol red thread test

Answer 9

anaesthesia is required with the schirmer test and not required in the phenol red thread test