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Flashcards in diagnostic stains Deck (41):
1

name 3 diagnostic staines

- fluorescein sodium
- rose bengal
- lissamine green

2

which stain will you use to see things on the cornea

flourescein

3

which stain will you use to see things on the conjunctiva

rose bengal and lissamine green

4

which 2 ways can flourescein be used

- topically
or
- injected systemically for flourescein angiography

5

what is always at hand when doing flourescein angiography and why

defibrillator because it can cause a cardiac arrest

6

explain why flourescein is not a true stain

- it colours the tear film
- the tear film does not invade intact corneal epithelium (i.e. it can't pass through the cornea unless it has an abrasion and thats when flourescein enters it)
- lipid membrane impermeable to water soluble polar water molecules
- epithelial damage means flourescein can gain access to deeper layers

7

what spectrum of absorbed energy maximally excites flourescein molecules

light thats absorbed maximally between 485 - 500nm (blue)

8

what nm of light does flourescein emit

between 525 - 530nm (green)

9

what wavelength of light does the burton lamp emit

305 - 410nm

10

what wavelengths do some RGPs absorb light between

315 - 400nm

11

what wavelength of light does the blue filter on the slit lamp emit

390 - 410nm

12

list 6 uses of flourescein

- assessment of corneal integrity (trauma, disease, contact lens a/c)
- rigid contact lens fitting
- contact tonometry
- TBUT
- lacrimal patency
- lacrimal drainage

13

how is lacrimal drainage assessed with flourescein

- px to blow nose and check if tissue is orange
- if not orange then means theres a blockage in the puncta
- can also monitor the amount of flourescein that is still in the eye so can check if conjunctiva still has flourescein which means it still hasn't drained away

14

what are the 2 contraindications of flourescein sodium

- known sensitivity
- dont put in with soft cl's

15

what is the caution of the multi dose bottles of flourescein

- contamination problems in hospitals in the 1950's
- flourescein is used on damaged cornea
- pseudomonas has an affinity for flourescein
- this progresses rapidly and can cause corneal perforation within 48 hours

16

how rapidly can pseudomonas progress and cause corneal perforation/ulcers

within 48 hours

17

what 2 forms of packaging is flourescein available in, what are the doses and what is the storage requirement

- minims 1% and 2%
- flourescein impregnated strip 1mg
- store below 25 degrees celsius

18

what 4 properties are thee about flourescein minims

- orange-yellow
- slightly alkaline
- contains buffer to stabilise solution
- may be combined with anaesthetic

19

what is rose bengal a derivative of

flourescein

20

what structures does rose bengal stain

- devitalised epithelial cells of cornea and conjunctiva
- stains mucous strands

21

what type of effect does rose bengal have

anti viral

22

rose bengal _________ on instillation, especially in ______ ______ conditions

rose bengal stings on instillation, especially in dry eye conditions

23

rose bengal may cause _____________ staining

rose bengal may cause punctate staining

24

rose bengal has a _________ effect on human _________ epithelial cells, enhanced by ____________ ___________

rose bengal has a toxic effect on human corneal epithelial cells, enhanced by light exposure

25

what forms of packaging and dosage has rose bengal been available in

- 1% minims (not commercially available)
- ophthalmic strips 1.3mg

26

list 5 conditions where rose bengal is useful

- keratoconjunctivitis sicca
- dendritic keratitis
- neuroparalytic keratitis
- exophthalmos
- pressure areas due to contact lens wear

27

what form of packaging and dose is lissamine green available in

ophthalmic strips 1.5mg

28

what are the actions of lissamine green similar to

rose bengal

29

list 5 ways in which lissamine green differs from rose bengal

- stings less
- less toxic
- no anti viral effects
- staining effect lasts longer than rose bengal
- it does not stain healthy cells like rose bengal does

30

how are the actions of lissamine green similar to rose bengal

like rose bengal it binds to severely damaged cells and is easier to view against lighter irises

31

when should you observe your staining after instilling lissamine green and why

1-4 minutes
- if observe too soon, staining pattern won't have developed
- if observe too late, some of the staining pattern may have faded away

32

what illumination must you begin with when observing lissamine green and why

start off with low illumination as high illumination will bleach out the appearance of some staining

33

what can be used when observing staining with lissamine green that will help

red filter wratten no. 25

34

there is some evidence to suggest that early signs of ______ ______ disease is more ____________ with lissamine green compared to ______________

there is some evidence to suggest that early signs of dry eye disease is more visible with lissamine green compared to flourescein

35

for the evaluation of staining, can use charts e.g. __________ grading scheme, but _____________ may be poor

for the evaluation of staining, can use charts e.g. oxford grading scheme, but repeatability may be poor

36

list 5 other stains which are not used commercially

- alcian blue
- trypan blue
- bromothymol blue
- methylene blue
- tetrazolium and iodonitrotetrazolium

37

what does aclian blue stain

mucus

38

what does trepan blue stain

mucus and dead cells which have undergone structural changes

39

what does bromothymol blue stain

degenerate and dead cells, mucus used to investigate damage by chemical agents

40

what does methylene blue stain

bacterial stain that will also stain nerve tissue

41

what does tetrazolium and iodonitrotetrazolium stain

tetrazolium stains degenerate cells (not living or dead), staining of tumours and assessing corneal grafts