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Ophthalmology SOH > Immunology > Flashcards

Flashcards in Immunology Deck (31):
1

Name 5 things in place to protect the eye from infection

Blink reflex
Tears
Mucous layer
Chemicals
Presence of immune cells

2

Blink reflex - immunological function

Pathogen clearing system

3

Tears - immunological function

Allows flushing of the eye

4

Mucous layer - function

Prevents things from sticking to the eye

5

Chemicals - function

Lysozyme
Lactoferrin

6

Immune cells in the eye - name 3

Neutrophil
Macrophage
Conjunctival mast cell

7

What is the principle APC in the eye? and where are most found?

Langerhans cells
Most found at corneo-scleral limbus

8

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

Conjunctiva

9

The cornea is vascular / avascular ?

Avascular

10

What is the function of the blood-ocular barrier?

Prevents the spread of systemic infection into the eye

11

Foreign organisms that come into the eye replicate slowly / quickly?

Quickly

12

Immune privilege - definition

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

13

Immune privilege and tissue grafts

Tissue grafts are normally attacked by the immune system as they are recognised by the body as foreign.
Tissue grades can survive for extended periods without transplant rejection in immune privilege sites.

14

Anterior chamber associated immune deviation (ACAID)

Placing foreign antigen into the ocular microenvironment.
Aims to down-regulate the immune response within the eye
Protects the eye from damage of an immune response

15

Disadvantages of immune privilege

Immune privilege breaks down if there is significant infection or injury

16

Sympathetic opthalmia - definition

Physical trauma to one eye which results in granulomatous uveitis in both eyes

17

Sympathetic opthalmia - cause

Trauma
Surgery

18

Sympathetic opthalmia - clinical features

Injured in one eye (exciting eye) initially but then there is inflammation in both eyes (exciting eye + sympathetic eye)

19

Sympathetic opthalmia - complications

Can lead to bilateral blindness (from a unilateral injury)

20

Keratoconjunctivitis sicca - clinical feature

Dry eyes

21

Hypersensitivity reaction - definition

Immune response that results in bystander damage to self

22

Type 1 hypersensitivity - eg

Allergic reaction
Acute allergic conjunctivitis

23

Type 1 hypersensitivity - mechanism

When body encounters allergen, B cells produce specific IgE
Specific IgE antibodies attach to mast cell receptors
Immediate release of vasoactive mediators (histamine etc)

24

type 2 hypersensitivity - eg

Ocular cicarical pemphigoid

25

Type 2 hypersensitivity - definition

Direct cell killing aka antibody mediated cytotoxicity

26

Type 3 hypersensitivity - definition

Immune complex mediated

27

Type 3 hypersensitivity - eg

Autoimmune corneal melting

28

Type 3 hypersensitivity - mechanism

Combo of antigens and antibodies which form complexes when they join together

29

Type 4 hypersensitivity - definition

Delayed type hypersensitivity (cell mediated)

30

Type 4 hypersensitivity - eg

corneal graft rejection

31

Type 4 hypersensitivity - mechanism

Exaggerated immune response