immunology of the eye Flashcards
what are the 2 types of immunity?
innate and adaptive
what are the features of innate immunity?
first line response
born with it
fast
non-specific
no memory
physical barrier
commensal bacteria
chemical agents
various cell types
what are the features of adaptive immunity?
acquired
slow
specific
memory T and B cells
learned
transferable
tolerance
what are the physical barriers of the innate immune system?
blinking
tears
what are the chemical agents of the innate immune system?
tears (lysozymes, lactoferrin, transferrin and IgA)
what are the cells involved in the innate immune system?
neutrophils
macrophages
mast cells
what are the antigen presenting cells involved in the adaptive immune system?
dendritic cells
Langerhans cells
B cells
macrophages
what is involved in lymphatic drainage of the adaptive immune system?
conjunctiva
lids to lymph nodes
what are the effector cells involved in adaptive immune system?
CD4+ T cells
CD8+ T cells
B cells
what type of hypersensitivity reaction is allergic conjunctivitis?
type 1
what are the features of allergic conjunctivitis?
bilateral
itchy
watery
red
vision unaffected
seasonal/trigger
what type of hypersensitivity reaction is thyroid eye disease?
type 2
what is the mnemonic to remember features of thyroid eye disease?
NO SPECS
what are the features of thyroid eye disease?
No signs/symptoms
Only symptoms
Soft tissue involvement
Proptosis
Extraocular muscles
Corneal involvement
Sight loss
what are examples of type 3 and 4 hypersensitivity eye diseases?
episcleritis
scleritis
uveitis
retinitis/vasculitis
what are the features of episcleritis?
normal vision
no pain
minimal discomfort
self-limiting
red
what are the features of scleritis?
painful (wakes them up at night)
pain on eye movement
vision could be affected
potentially blinding
what are the features of uveitis?
common
varied
blinding
think systemic
what is immune privilege?
where certain parts of the body e.g. eye have protection from usual immune defence actions
immune system kept in check to avoid unnecessary attacks
how does immune privilege help maintain clear vision?
stops immune system attacking the eyes - if the immune system were to attack then there would be damage, inflammation or scarring of the eyes which would affect how clearly we can see
by limiting the immune system’s activity in the eye what does it ensure?
eyes can function without interference, keeping vision clear and protecting from harm
what type of reaction if a corneal graft injection?
type 4 hypersensitivity
