CSC - Opthalmology practical Flashcards
What colour are filters usually?
blue and green, sometimes yellow
Use - slit lamp
use for contour of surface structures and inner structures an gauge depth of corneal ulcers. Lamp is binocular so better depth of vision.
How do you differentiate blood from pigment in eye (especially if chronic and has degenerated a bit)?
change from white to green filtered light – blood will change colour from red to brown, pigment will not change at all.
Where is a lesion at a focus of +12?
lens
Where is a lesion at a focus of +20
cornea
Use - DDO
you can observe both pupils in the same beam of light and you can use this to check for isochoria (i.e. pupils of different sizes).
Method - CDO
– turn light beam intensity down so as not to hurt the eye. Scan eye up and down, medially and laterally. Remember it is a magnified view so many scans are necessary.
Which surface should face towards you on CDO?
convex surface facing towards you
Why use saline for a fluorescein strip rather than tap water?
irritation of chloride on eye with tap water.
T/F: fluorescein is excited by blue light
True
Time for proxymetacaine to work
20 seconds
Normal eye IOP pressure = ?
12-22/24 mmgHg
What does increase in IOP suggest?
retina pressures (possibly glaucoma)
What does decreased IOP suggest?
inflammation
T/F: it is good to apply a viscous tear to the eye after tanometry
True
