Immunology and the eye

Question 1

In what three ways are the immune vulnerabilities of the eye compensated for?

Answer 1

blink reflex, physical/chemical properties of the eye surface, limited surface exposure/size

Question 2

How do tears physically contribute to protecting the eye from pathogens?

Answer 2

flush organisms away, have an anti-adhesive mucus layer

Question 3

What chemical components of tears make them useful antimicrobials?

Answer 3

lysozyme, lactoferrin and transferrin, complement, tear lipids, secretory IgA

Question 4

What immune cells are present in tears?

Answer 4

Neutrophils, macrophages, mast cells

Question 5

Why is the eye an immune-priveleged site?

Answer 5

Inflammatory reaction can cause organ damage

Question 6

What is the only area of the eye with lymphatic drainage?

Answer 6

The conjunctiva

Question 7

What advantage does the immune privelege of the eye have?

Answer 7

Makes transplants more likely to be accepted

Question 8

What would be an example of:

a) type 1 hypersensitivity
b) type 2
c) type 3
d) type 4

Answer 8

a) allergic conjunctivitis
b) (direct cell killing- killer cells, complement) ocular cicatricial pemphigoid
c) (immune complex mediated) autoimmune corneal melting
d) (delayed hypersensitivity) corneaal graft rejection