Card Set Information

2012-10-30 12:01:59
DO Direct Opthalmoscopy optometry

Show Answers:

  1. What is the slit used for?
    to see elevations and depressions
  2. What is the mag, FOV of DO?
    15X 6-10 deg
  3. What do cataracts appear like with a DO?
    milky appearance
  4. How would you identify a floater with DO?
    casts a shadow on the retina
  5. What happens when there is a very thick neural rim?
    no to little cupping
  6. What happens when there is a very thin neural rim?
    very deep and large cup
  7. What is the usual C/D ratio?
  8. What is the reason for the pallour of the OD?
    absence of axons
  9. How is the mirroring in both eyes useful?
    can use for differential diagnosis by comparing the two eyes
  10. What is the lamina cribosa and what does it look like?
    • mesh like structure make from collagen fibres which the nerve fibres exit the optic nerve from
    • looks liek grey dots in the cup
  11. Rule of vein/artery density of neural rim?
  12. What is shelving?
    • when the rim acts as a shelf for the bvs to run along it then disappear under it
    • reappears in the cup
  13. What is notching?
    • when GCs are damaged- becomes malnourished
    • donut of rim isnt round anymore
    • ISNT becomes INST
  14. What is a temporal fundus ectasia?
    bvs travel to temporal
  15. What is a nasal fundus extasia?
    • tilted disc
    • bvs travel nasally
  16. What is superior dysversion?
    • tilted disc
    • bvs travel superiorly
  17. What is inferior dysversion
    • tilted disc
    • bvs travel inferiorly
  18. How does the ILM look like through a DO?
    • retina looks shiny/wet in young px
    • not so much with aging
  19. What gives the retina its colour?
    the pigmentation in the RPE
  20. What happens when there is little pigmentation?
    can see other structures like choroidal vessels and vertex veins
  21. What is a tesselated/tigroid fundus?
    as you increase in age, pigmentations becomes patchy and appears tesselated
  22. What is a RPE crescent?
    • termination of pigment
    • looks like it fades outwards from the disc edge
    • sometimes terminates earlier than choroid
  23. What is a choroidal crescent?
    • narrow ring of pigmentation- sharp edges
    • no RPE or little ontop of it
    • or where retinal tissue has been pulled away to reveal bare choroid
  24. What is a scleral crescent?
    • white crescent at disc edge
    • bare sclera
  25. What is the difference bw and artery and a vein?
    • vein more blue-red and larger
    • artery more warm-red and smaller
  26. What is a cilioretinal artery?
    • independent blood flow system deriving form the the choriocapillaries rather than the central retinal artery- just incase of a blockages
    • appears temporally and heads towards the macula
  27. What happens if you see a pulse in the artery?
  28. What can be used on a DO to see the NFL?
    red free filter: green light
  29. What are white dots on the fundus?
    muller foot plate cells
  30. What does the macula look like through the DO?
    • yellow brown pigmented- highly variable form person to person
    • bright reflex at foveola in young px: light reflected from foveal pit
    • age: depigmentation or pigment clumping
  31. What is a bergmeister papilla?
    • embryonic structure which is a remnant of a hyaliod artery
    • appears as a small tuft of fibrous tissue at the centre of the OD
  32. What is a mittendorf dot?
    small dot on posterior lens: remnant of hyaloid artery
  33. What is a vascular loop in the vitreous?
    the cilioretinal artery grows into the retina, realised it is growing the wrong way and turns back leaving a loop of vascularture
  34. What are white fluffy bunny tail spots in the fundus?
    myelin sheathing of optic nerve fibres extending past the lamina cribosa
  35. What are creamy spots?
    soft hard exudates
  36. What are some red spots on the fundus?