Conditions of the Conjunctiva, Third Eyelid and Lacrimal System in Dogs

Question 1

What is the name of the cartilage in the third eyelid?

Answer 1

Hyaline cartilage

Question 2

Which local anaesthetic would you use to examine the conjunctiva and the third eyelid?

Answer 2

Proxymetacaine 0.5%

Question 3

List four classes of bacteria that are commensals of the conjunctiva.

Answer 3

Staphylococcus spp.
Bacillus spp.
Corynebacterium spp.
Streptococcus spp.

Question 4

What is chemosis?

Answer 4

Conjunctival oedema

Question 5

Where might follicular hyperplasia be seen?

Answer 5

Inner aspect of the TEL
Upper fornix

Question 6

List the causes of primary conjuctivitis

Answer 6

Follicular conjunctivitis.
Juvenile conjunctivitis (under 18 months).
Infectious - viral (CDV, CHV-1, CAV-2), parasitic (Thelazia, Leishmania)
Allergic conjunctivitis.

Question 7

List four methods of the empirical treatment of conjunctivitis

Answer 7

Topical antibiotics, topical anti-inflammatories, lubrication, cleansing

Question 8

Which antibiotics would you use to topically treat conjunctivitis?

Answer 8

Fucidic acid or chloramphenicol

Question 9

What is cherry eye?

Answer 9

Red, homogenous mass arising from the bulbar aspect of the third eyelid.

Question 10

Which surgical technique would you use to treat a prolapsed third eyelid and which suture material would you use?

Answer 10

Modified Morgan Pocket Technique using microsurgical absorbable braided suture 5-0 or 6-0.

Question 11

What is the success rate of third eyelid gland surgery?

Answer 11

80%

Question 12

What are the three layers of the pre-corneal tear film?

Answer 12

Deep mucin layer.
Intermediate aqeuos layer.
Superficial lipid layer.

Question 13

Which glands produce the lipid phase of the tear film?

Answer 13

Meibomian glands

Question 14

Which glands produce the mucus layer of the tear film?

Answer 14

Conjunctival goblet cells

Question 15

What causes the majority of cases of keratoconjunctivitis sicca?

Answer 15

Immune-mediated adenitis

Question 16

Which breed has congenital lacrimal gland hypoplasia, predisposing them to KCS?

Answer 16

Yorkie

Question 17

List three causes of iatrogenic KCS

Answer 17

Anaesthetics, atropine and drug toxicity (trimethoprim/sulfonamide, paracetamol)

Question 18

Which immunomodulating agents can be used to treat KCS?

Answer 18

Topical cyclosporine or tacrolimus

Question 19

What is the surgical treatment for KCS and what does it involve?

Answer 19

Parotid duct transposition - parotid duct cannulated, dissected and transposed to exit in the lower fornix of the lower eyelid.