BV 2 - EF

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BV 2 - EF
2014-11-30 23:14:09
eccentric fixation

eccentric fixation
Show Answers:

  1. What are key notes when diagnosis EF?
    • central/eccentric fixation
    • steady/unsteady
    • which eye
    • magnitude
    • direction
  2. What is EF?
    • incorrect visual direction
    • monocular
    • assoc with strabs amb>aniso
  3. What are some of the features of unstable fixation?
    • saccadic intrusions and increase in drifts
    • lots of over and undershoots
    • jerky pursuits
    • fixation is more steady if dark adapted
  4. What are some tests for EF?
    • Visuoscopy
    • Brock Givner after image
    • Haidinger brushes
  5. Haidinger brush viewed with OD - sees brush 1cm to the right standing 20cm away?
    5PD temporal EF OD steady
  6. How does the Haidinger brushes work?
    • Foveal tag procedure
    • Diffraction of Henle's Fibre Layer - see brush/propeller
  7. Disad of Haidinger's brushes?
    • Sometimes they arent able to see the brushes
    • subjective - patients need to be old enough to respond with answers
  8. When are EF tests indicated? Entopic?
    • ONLY when VA is decreased
    • entopic - only if px >7yo and visuoscopy failed - too unsteady
  9. Brock Givner - looking with OD (OS was zapped) sees vert line 1.6cm to the left of dot standing 40cm?
    4PD nasal EF of OD - steady