Immunology and the eye

Question 1

What is purpose of the immune system?

Answer 1

to identify and eliminate harmful microorganisms and harmful substances

Question 2

How does the immune system identify harmful substances

Answer 2

by distinguishing self from non self and by recognising danger signals (i.e. from inflammation)

Question 3

what are 3 key features of the innate immune system?

Answer 3

rapid - (mins to hours)
non-specific
no memory

Question 4

What are 3 key features of the adaptive immune system?

Answer 4

gradual response (>days)
specific
memory

Question 5

What is the physical protective barrier of tears

Answer 5

flushing

mucous layer anti-adhesive

Question 6

what are lysosomes in tears protective agains?

Answer 6

gram -ve fungi

Question 7

what are lactoferrin and transferrin in tears protective against

Answer 7

gram +ve fungi

Question 8

how do tear lipids protect the eye ?

Answer 8

antibacterial to cell membranes

Question 9

how is secretory IgA present in tears protective?

Answer 9

prevents attachment

Question 10

what are the 3 cellular immunological components of tears?

Answer 10

neutrophils
macrophages
conjunctival mast cells

Question 11

What does the acquired immune system require?

Answer 11

antigen presenting cells

lymphatic drainage to node

Question 12

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

Answer 12

the conjunctiva

Question 13

What are the features of the conjunctiva that help with the adaptive immune system

Answer 13

The only part of the eye with lymphatic drainage
dendritic cells act as APCs
MALT
commensal bacteria

Question 14

what features of the cornea and sclera make immunocompromised?

Answer 14

avascularity
no lymphatics
down regulated immune environment
relative lack of antigen presenting cells

Question 15

What is immune privilege?

Answer 15

being able to tolerate the introduction of antigens without eliciting an inflammatory immune response

Question 16

Which parts of the body have immune privilege?

Answer 16

Brain/CNs
testes
placenta
eyes

Question 17

what features give some parts of the eye immune privilege?

Answer 17

blood barrier

lack of lymphatic drainage

Question 18

what is sympathetic ophthalmia?

Answer 18

A rare bilateral granulomatous uveitis

Question 19

What can cause sympathetic ophthalmia?

Answer 19

penetrating trauma or surgery to the eye

Question 20

What are the primary mediators in sympathetic ophthalmia?

Answer 20

T cells

Question 21

What is the injured eye known as in sympathetic ophthalmia?

Answer 21

exciting eye

Question 22

What is the non-insured eye known as in sympathetic ophthalmia?

Answer 22

sympathising eye

Question 23

true/false

clinical both eyes appear the same in sympathetic ophthalmia, regardless of which is the exciting eye

Answer 23

true

Question 24

How many different types of hypersensitivity are there?

Answer 24

4 types

Question 25

What is a type I allergic reaction?

Answer 25

immediate hypersensitivity

Question 26

What is a type II hypersensitivity reaction?

Answer 26

direct cell killing

Question 27

What is a type III hypersensitivity reaction?

Answer 27

immune complex mediated

Question 28

What is a type IV hypersensitive reaction?

Answer 28

delayed type hypersensitivity

Question 29

What is the role of mast cells in allergic reactions?

Answer 29

Express receptors for Fc region of IgE antibody on their surface

Question 30

what type of hypersensitivity is acute allergic conjunctivitis?

Answer 30

Type I

Question 31

In a type II hypersensitivity reaction what are the cells killed by?

Answer 31

macrophages / natural killer cells | complement (membrane attack complex)

Question 32

What type of hypersensitivity is Ocular cicatricial pemphigoid?

Answer 32

type II

Question 33

what type of hypersensitivity is autoimmune corneal melting?

Answer 33

Type III

Question 34

What type of hypersensitivity results in a corneal graft rejection?

Answer 34

Type IV