Lecture 10 - Lacrimal system and Dyes

Question 1

What is the main function of tears?

Answer 1

Lubrication between eyelids and globe, Atmospheric oxygen for cornea, removes debris and contains ANTIBACTERIAL substances

Question 2

What are the three layers of the tear film?

Answer 2

LAM
Lipid (outermost layer) - delays evaporation and provides lubrication - Meibomian

Aqueous (Middle) - water layer - Lacrimal

Mucin (inner) - Mucous layer - “ADHESION to Cornea” - Goblet cells

Question 3

What is the production mechanism for the tear system?

Answer 3

Basic and Reflex blink

Question 4

What is the distribution mechanism for the tear system?

Answer 4

Blinking and lids

Question 5

What is the drainage mechanism of the tear system?

Answer 5

Nasolacrimal

Question 6

How much is lost to re absorption and evaporation?

Answer 6

25%

Question 7

Reflex secretion _____ the volume in reponse to a stimulus?

Answer 7

Increase

Question 8

What CN carries Afferent nerve fibers?

Answer 8

CN 5

Question 9

What is the Efferent CN?

Answer 9

CN 7

Question 10

What are the 3 components for corneal reflex?

Answer 10

Lacrimation, Miosis (EW) and Blinking (Facial Nucleus)

Question 11

What does epiphora mean?

Answer 11

Overflow of tears

Question 12

What is another name for tear meniscus?

Answer 12

Tear prism

Question 13

What is the normal TMH?

Answer 13

0.2mm tall

Note: It is good to start in the initial scanning of the lids to look at the TMH. During the exam there will be tearing, thus giving you an abnormal reading

Question 14

If you see foamy or soapy tears, what deficiency could that be?

Answer 14

MGD

Question 15

What type of test do you check for tear production?

Answer 15

Schirmer 1 and 2

Note: This tests for both reflex and basic

Question 16

What test do you use for distribution?

Answer 16

TBUT

Question 17

What test does the Jones dye test 1 and 2 look for?

Answer 17

Drainage issues

Question 18

In schirmer 1, how much time should you wait for the process?

Answer 18

5 minutes

Question 19

How many minutes do you use for Schirmer 2?

Answer 19

2 minutes

Question 20

What type of liquid do you put fluorescein strips?

Answer 20

Saline

Question 21

Where do you place a fluorescein strip?

Answer 21

lower cul de sac

Question 22

What do you tell your pt when you would like to conduct a TBUT test?

Answer 22

Give 2 good blinks and hold for as long as you can

Question 23

When you notice that immediately after blinking, you notice there is immediate evaporation. What has occurred?

Answer 23

Mucin layer is inadequate

Question 24

What type of dye would you use for Jones 1

Answer 24

Fluorescein w/ no anaesthetic

Question 25

When you notice a bright glow when using fluorescein, what could that mean?

Answer 25

epithelial cell loss

Question 26

You notice SPK staining all over the eye, what could be the cause?

Answer 26

Viral infection or Medicamentosa

Question 27

How would SPK be dispersed with an individual with dry eyes?

Answer 27

Usually IP but can be inferiorly

Question 28

What is bell’s phenomenom?

Answer 28

Upward rotation of globe on lid closure

Question 29

If you would like to evaluate palpebral conj, what type of diagnostic stain do you use?

Answer 29

NaFL

Question 30

What type of stain do you use when you want to observe devitalized corneal tissue?

Answer 30

Rose Bengal

Question 31

What are the three advantages of Lissamine Green compared to Rose Bengal?

Answer 31

Less toxic
Doesn’t last as long
Doesn’t sting as much

Question 32

When preforming a corneal sensitivity test, what cranial nerve damage is usually the first sign?

Answer 32

CN V

Question 33

What area of the eye do you touch with a cotton wisp?

Answer 33

Central cornea

Note: If you see a bend in the cotton wisp, that is positive damage to the CNV

Question 34

What is Seidel’s sign?

Answer 34

There is a leakage of aqueous streaming thru.

“water fall”