Week 4 Lacrimal Review Questions

Question 1

What 3 glands contribute to the aqueous portion of the tear film and what are their contributions in dogs

Answer 1

Orbital lacrimal gland 50-62%

Gland of the nictitaing membrane 35-50%

Accessory lacrimal glands <3%

Question 2

What nerves innervate the lacrimal glands? What cranial nerve abnormality is associated with dry eye? Which part of the ANS increases tear production?

Question 3

What are the 3 layers of the tear film, what structures produce them and what are their functions

Answer 3

Mucin- goblet cells, fills in irregularities of corneal cells

Aqueous- Lacrimal gland, GNM, accessory lacrimal glands

Lipid- meibomian glands, enhances lubriaction of lid movement

Question 4

Describe the pathway for outflow of tears beginning at the lacrimal lake, and ending at the nasal vestibule

Answer 4

Lacrimal puncta, canalculi, lacrimal sac, nasolacrimal duct, nasal puncta

Question 5

Where in the naslacrimal outflow tract are obstructions most commo?

Answer 5

Proximal portion of nasolacrimal duct encased in bone & narrow

Question 6

Describe clinical signs and microscopic changes of the cornea of KCS. Which breeds of dog are predisposed