Card Set Information

2014-11-11 02:14:14
Show Answers:

  1. FOV in BIO is __ DD, __mm or ___deg and depends on the ___
    • 8DD
    • 12mm
    • 40-75deg
    • condenser lens
  2. what is scleral indentation used for?
    name one example
    • For further evaluation of periphery
    • ora serrata
  3. BIO allows a clear view despite ____, ____ or ____
    • high ametropia
    • hazy ocular media
    • lenticular opcities
  4. Advantages of BIO (x5)
    • 1 quick assessment of entire fundus periphery + vit
    • 2 depth perception
    • 3 larger FOVĀ 
    • 4 allows clear view despite high ametropia, hazy ocular media or lenticular opacities
    • 5 scleral indentation
  5. Disadvantages of BIO (x4)
    • 1 image is reversed and inverted = initially challenging with interpretation and recording
    • 2 mydriasis is required
    • 3 lower mag required
    • 4 light toxicity with prolonged exposure
  6. FOV in DO is __ DD, __mm or __deg
    • 2 DD
    • 3mm
    • ~8deg
  7. The two types of BIO are:
    • headmounted
    • specs mounted
  8. BIO accessories (x4)
    • flip down mag
    • vid camera attachment
    • teaching mirror
    • coloured covers
  9. BIO has an _____ and an _____ system
    illumination and observation
  10. Image seen on BIO is (x5)
    real, magnified, aerial, reversed and inverted
  11. In the illumination system, the light source is ____ and a _____ is used too focus the light
    • offset
    • condensing lens
  12. To keep the image in focus with the observation system, we need to _______ but BIO's have a ____ in it and so _____ will have no trouble using BIO's
    • accomodate
    • +2D lens
    • presbyopes
  13. the image formed from the observation system is ____
  14. how does BIO work?
    light directed into px eye is reflected back from the retina thru the CL
  15. how is the stereoscopic image possible?
    • prisms in BIO decreases PD of the optom such that both pupils of the optom are imaged within the px's pupil
    • dilation assists with this
  16. FOV and mag relo
    FOV inversely proportional to the mag of the CL
  17. the mag to FOV of image dependent on ________
    the choice of CL
  18. For a standard 20D lens, the mag is __ and the FOV is ___
    • 3x
    • 35 deg
  19. Lenses of lower power offers ____ mag but ____ FOV
    greater mag but smaller FOV
  20. lenses of greater power offers ____ mag but _____ FOV
    less mag but greater FOV
  21. Which surface of the CL faces the optom?
    convex surface
  22. Why is yellow light better tolerated by the px?
    yellow light blocks blue light
  23. Condensing lenses are typically _________
  24. How does yellow light affect the view of the fundus?
    • the fundus is red-orange, so is minimally affected
    • pale discs may appear yellow-ish
  25. What does a multi-layered anti-reflection do on a CL?
    • decreases reflection
    • increases light transmission
  26. Condensing lens features
    • multi-layered anti-reflection coating
    • some CL available in yellow glass
  27. Light and damage
    • light from BIO is exceedingly bright - warn px beforehand
    • no more than 40sec to look at one area of the fundus
    • small eye mvts = unlikely
  28. axial misalignment of the CL =
    • too close/far from light source
    • 2 effects which dim the image
    • 1 image of light source on pupil is defocused = less light into pupil
    • 2 width of emergent ray at sighthole is too large = cannot view full image
  29. transverse mvt of CL
    • too high/low CL
    • light may not focus through the pupil
  30. needs for scleral indentation
    • allows us to obtain a dynamic view of the retina
    • when viewing ant aspect of fundus, we look across surface of retina, making it difficult to detect some surface features, esp depth
  31. Scleral indentation procedure
    • 1 use thumb + forefinger to hold CL with one hand, resting on px forehead if necessary
    • 2 hold scleral depressor vertically with other hand, and press tip on eyelid, applying gentle pressure to the sclera
    • 3 have px look in opp direction, apply pressure, then direct px gaze towards depressor
  32. Indications of scleral indentation
    • suspected retinal tear/detachment cases when BIO alone cannot determine if a hole is in qn
    • e.g. peripheral retinal hole vs pigment spot/haemorrhage
    • holes may look larger/reveal a surrounding 'white cuff'/ring or oedema vs fixed spot being elevated only
  33. contraindications for scleral indentation
    • 1 recent intraocular surgery e.g. cataracts
    • 2 anterior or iris-attached IOLs
    • 2 traumatic hyphaema (pooling of blood in the ant. ch)
  34. what is hyphaema
    pooling of blood in the ant ch
  35. what not to do with scleral indentation
    • 1 do not indent too close to limbus (puts pressure on CB)
    • 2 avoid pressure on tarsal plate --> 2ndary inflammation of MG
    • 3 avoid conj even with anaesthtic
    • 4 avoid if px has ant or iris attached IOLs
    • 5 procedure may be quite painful if IOP is high
  36. BIO landmarks
    • 1 vortex-vein ampullae
    • 2 long ciliary nerves
    • 3 short ciliary nerves
    • 4 ora serrata
  37. How many vortex vein ampullae may been seen in each eye?
    • 1 or more per quadrant
    • 4-15 per eye
  38. Vortex vein ampullae will be found darker in?
    causcasians when px looks on a diagonal
  39. Vortex-vein ampullae features
    • 1 red-octopus-like structure in mid-periphery
    • 2 appearance dependent on overall fundus pigmentation (more likely seen in caucasian pxs)
    • 3 post border lies on the equator of the globe
  40. Where are long ciliary nerves typically seen?
    when the px looks right or left
  41. long ciliary nerves features
    • yellow orange lines may have parallel pigmented borders
    • seen at 3 and 9 o'clock along the horz meridian of the choroid, separating sup and inf fundus
  42. how many short ciliary nerves are typically seen in each eye?
  43. short ciliary nerves can be found when the px looks
    11, 1, 5 or 7 o'clock
  44. where are short ciliary nerves located?
    on either side of the vertical meridian within the choroid
  45. what do short ciliary nerves look like?
    fine light coloured branching structures
  46. the ora serrata is more scalloped on the _________ half
  47. when we see increased pigmentation around the ora serrata, we are looking at the ___
    vitreous base
  48. the vitreous base is indicated by the
    increased pigmentation around the ora serrata
  49. the orange tissue at the ora serrata is the _____
    pars plana (ciliary epi)
  50. the pars plana (ciliary epi) is indicated by the ___________
    orange tissue at the ora serrata
  51. ora serrata is
    the peripheral termination of the sensory retina
  52. optom moves in _____________ to the px's gaze
    the opposite direction
  53. the direction the px looks = __________ we observe
    • the same part of retina
    • e.g. px looks up, we observe sup fundus
  54. how many views of CL to cover whole fundus?
    at least 25
  55. easiest way to record is to
    • pick the point on the card where the drawing needs to go
    • invert and record, draw exactly what you see in the CL
  56. on the clinic forms, anatomical landmarks are used to orientate ourselves
    • from inner to outer ring
    • equator
    • ora serrata
    • pars plana
  57. procedure for BIO
    • 1 habitual VA
    • 2 corneal integrity check
    • 3 measure IOP - to detect for post-dilation IOP increase
    • 4 check px allergies to drops or anaesthetics
    • 5 seat px at eye level or higher
    • 6 adjust BIO: head straps, oculars (tilt and PD), position of light, intensity of light (start with low-medium intensity)
    • 7 CL (silver ring to px) held b/t thumb and index; rest 4th and 5th on px forehead
    • 8 direct px's gaze straight ahead
    • 9 fully outstretch arm and direct light into px's pupil; look for red reflex
    • 10 initially see px's pupil and eyeball; pull CL out until red reflex fills image and is clear
    • 11 may need to tilt lens slightly/fine adj to vertex distance to maintain clarity and reflection free viewing
    • 12 the shape of pupil and image seen changes as px gaze changes = image will not totally fill the CL in extreme directions of gaze
  58. ora serrata is ________ nasally and _______ temporally
    • narrowest
    • widest
  59. ora serrata is narrowest ___ and widest ____
    • nasally
    • temporally
  60. pars plana is
    • where th choroid and retina meet at the ora serrata
    • it looks like normal retina