Lab final Flashcards
what is a clinical trial?
A research of human volunteers to answer health questions
Institutional Review Board
All clinical trials in the US are monitored.
Sensitivity
How many the test correctly identifies as having a dz in a given population
Specificity
How many healthy people the test identifies as healthy.
What two types of questions are using during case history
- open ended
2. deductive
Open ended questions
Allow pt. to diverge any information they think are pertinent. EX: what brings you in today
Deductive question
Allow clinician to deduce a possible cause of patient’s complaints. EX: is it one or both eyes?
What questions should you use to cover case history?
D-uration O-onset F-requency D-describe A-associated R-eleif S-everity
Ways to describe onset
- Acute-less then 6 weeks
2. chornic-more then 6 weeks
Cultures
Help with bacteria ID as well and microorganism sensitivity to specific AB
Cytology
Studies help to ID bacteria, virus, fungi, and allergins.
Culture studies
Center around the growth of the microorganism from an eye on a plate. The plates are examined to find out what is growing
Sensitivity Studies
Grow the culture and put on different AB to see what will kill it. Will get report back on type of meds to take orally. Does not apply to topical meds.
Anesthetic consideration
Cultures should be taken before applying anesthetic because they can inhibit growth of some organisms.
Types of culture
Aerobic, anerobic, fungal, myocbacterial, viral, parasites.
What plates are requested for all eye cultures?
Blood and chocolate agar
Blood agar
Most commonly used. This medium grows most bacterial organisms. (not neisseria or Haemophilus)
Chocolate agar
Good for neisseria and haemophilus
Thioglycolate Broth
Used as a transport medium. Grows both facultative anaerobic organisms and aerobes. Grows fungi
Tryptic Soy broth
Grows anaerobic bacteria
Viral media
Has AB to kill bacteria and kick out competition for virus.
Culturette
Prepared transport container used for cultures.
Which eyes should you culture?
Both eyes to compare the culture!
Old culture method
Each culture plate divided into 4 quads so you can place left eye’s lids and conj. on the same side of the plate and right conj. and lid on right side of plate.
New culture method
Each culture plate divided into 3 sections. A separate media plate is used for each new culture location.
Where is the usual site for obtaining conj. specimens for culture?
The inferior palpebral conj.
What should you label each culture with.
Patients name, doctors name, date, time, test order, specimen source (which eye and which part of eye) if anything is suspected.
How to obtain a culture from a corneal ulcer?
- A kimura platinum spatula (must heat and cool to serialize)
- Sterile calcium alginate swab dipped in TSB (fungi or bacteria culture)
- Sterile Dacron/polyester swab (viral culture)
Ways to plate corneal swabs?
- Two rows of C with each C representing a different sample area
- entire plate reserved for one sample
Smears and scrapings
cytology. Used when an ocular infection needs culturing to ID organisms and get diagnosis.
Staining with smears and scraping
- Gram stains: differ between pos and neg
2. Giemsa stain: used when etiology of organism is unknown and info is needed regarding cytological response.
Culturing with smears and scraping
Plate them on a clean glass slide (not a plate) and then fix the slide.
Positive staining
When there is a pooling of the stain in epithelial defects
Negative staining
When there is elevated epithelium that causes fluorescein to collected at the base of the heaped area
No staining
Occurs when there is intact epithelium
Sodium fluoroscene
Used with a cobalt filter to evaluate the integrity of the cornea and tear film
What does Lissamine green stain
Stain devitalized cell, mucus and keratin. Can view with white light.
What does Rose Bengal Stain
Stains devitalized cells as well. View with white light. Different from lissamine green as it stings upon instillation.
Line of Marx
Check for staining at line of marx. This is area from lid margin to meiobomian glands. The thicker the line, the more severe the dry eye. A line of marx from the margin to the meiobomian glands is considered severe.
Schirmer test
Use to measure the volume of aqueous in the eye. Put the strip along the later 1/3 eyelid. Have patient relax with eyes closed. After five minutes take the reading.
Values for schirmer
A normal eye will wet between 10-30 mm in schirmer 1 and 2. Measurments between 5-10 are borderline and those below 5 are suggestive of dry eye
Schirmer 1
performing the schemer without anesthetic. Test of reflexive tearing and basic tear levels
Schirmer 2
Using anesthetic. Measure the basic secretory tear level.
Phenol red test
Does not require anesthetic. Put curved portion over the temporal aspect of the lower lid. Leave for 15 seconds and remove and measure amount of moisture on the thread.
Phenol red readings
20 mm or greater is normal
11-19mm is borderline
0-10 mm is dry eye.
TBUT times
10-15 seconds is normal. Less then 10 seconds is indicative of dryness.
tear meniscus values
A normal tear meniscus will be about .20 mm +/- .04 mm. .15 mm is a borderline measure. .10 +/-.04 may be a sign of dry eye.
Jones Dye Test
Determines if the lacrimal drainage system is working.
Jones Dye Test 1
Put 4 sodium fluoroscene strips in the eye. After five minute have patient occlude one nostril and blow into kleenex. If NaFl present test is positive. If not wait five more minutes and blow again. If still none hold a cotton tip applicator in the nose and rub for dye. If still none massage the lacrimal sac and ask patient to blow. If NaFl is now evident it indicates narrowing or a partial obstruction. If no NaFl a blockage is possible and jones 2 is performed
Jones 2
Irrigate the nasolacrimal system with saline solution through inferior punctum after applying NaFl. Recover some of the saline by having patient lean forewarned and expectorate into a basin or blow nose into a white tissue. Inspect for NaFL. positive=system has a functional blockage. Negative=functional blockage exists that is nearer to the punctum then canaliculus.
Indirect Illumination
The microscope is focused on an area immediately adjacent to the illuminated tissue.
Retroillumination
Light is reflected off the anterior surface of the iris as the cornea is focused. Lesion will be backlighted and appear black due to absorption of reflected light. Can also perform this will illumination of fundus.
Oscillating
Use the illumination arm or rotate the mirror back and forth while viewing the point of interest.
Specular reflection
60 degrees for endo. Optic section for endothelium.
Sclerotic Scatter
Put light on temporal limbus and see how much of a limbal glow you get.
Slit lamp reticule technique for lesion measurement
Focus slit lamp on lesion. Reduce the length of the beam to coincide with the lesion and record measurement in mm. Rotate the reticle to the horizontal position and repeat.
PD rule technique for measuring
Focus the slit lamp on the lesion and center the beam along the longest height of the lesion. Reduce the height of the beam to the size of the lesion while staying in focus. Have patient sit back and hold the pd ruler to the beam and make sure it is in flu focus and measure the height of the light in mm.
Why do we do double lid eversion
To gain access to the superior fornix.
Meiobomian gland transillumination
Place the transilluminator under the exterior of the everted eyelid and turn up to high. Unhealthy truncated glands or absent glands will appear dark
Heat therapy/warm compress for meiobomian gland disfunction
Heat eye masks according to package and apply to closed eyelids 2-3x daily for 10-15 minutes.
meiobomian gland expression
Cold requires 20-30lbs of P. Heating only requires 10 lbs.
How to get plug into punctum?
Must pull the eye laterally!
What acid do you use for lesion destruction?
Dicholoracetic acid.
RPS MMP-9
Will indicate if the tear film has elevated levels of mmp-9 (an inflammation marker)
Signifigant values for tear lab
Noted for dry eye if osmolarity greater then 308 or greater then 8 difference between the two.
Lipiview signifigant values
Tear layer less then 60 nm thick or incomplete blink of greater then 40%
Korb Meiobomian GLand Expressor
Signifigant for dry eyes if less then 6 glands are excreting.
Currette
Tool used to dig stuff out of chalazion after it has been clamped by the chalazion clamp
