CDCA OSCE STUDY GUIDE WITH COMPLETE
ANSWERS
◉ What's brought you in today?
Have you worn xl before?
What do you want them for ?
How many day and hours ?
Ever been told not to wear contact lenses?
GH,OH,medication
Vdu
Occupation and hobbies
Smoke
Lee?
Answer: History and symptoms new fit
◉ HVID, VPA, pupils size, HVID IS LIMBUS TO LINBUS - TD lens
needs to be 2mm bigger . Lens needs to be 1.5mm bigger than max
pupil size
Answer: What lens paramaters do you need for soft lens?
◉ BOZR, TD and power
Answer: What lens parameters do you need for RGP
, ◉ Work out the difference in Ks, to work out corneal astig using 0.05
diff is 0.25 dc. Then determine how much steeper the BOZR needs to
be from the flattest k
Answer: How do you work out the BOZR
◉ Ocular astig = corneal + lenticular astig
Answer: How do you calculate the power
◉ Regular = 90 deg apart, irregular = not 90 deg apart, WTR IS
FLATTEST ON H, ATR is flattest on v, oblique is flattest 30 deg out
Answer: Diff types of astig
◉ Ocular - cornea . Spec dc - corneal via 0.05k diff = 0.25dc
Answer: How do you work out the residual astig
◉ Assess va, cover le start with + side
Answer: How to preform an over refraction
◉ Increase bc
Answer: If lens fits steep?
ANSWERS
◉ What's brought you in today?
Have you worn xl before?
What do you want them for ?
How many day and hours ?
Ever been told not to wear contact lenses?
GH,OH,medication
Vdu
Occupation and hobbies
Smoke
Lee?
Answer: History and symptoms new fit
◉ HVID, VPA, pupils size, HVID IS LIMBUS TO LINBUS - TD lens
needs to be 2mm bigger . Lens needs to be 1.5mm bigger than max
pupil size
Answer: What lens paramaters do you need for soft lens?
◉ BOZR, TD and power
Answer: What lens parameters do you need for RGP
, ◉ Work out the difference in Ks, to work out corneal astig using 0.05
diff is 0.25 dc. Then determine how much steeper the BOZR needs to
be from the flattest k
Answer: How do you work out the BOZR
◉ Ocular astig = corneal + lenticular astig
Answer: How do you calculate the power
◉ Regular = 90 deg apart, irregular = not 90 deg apart, WTR IS
FLATTEST ON H, ATR is flattest on v, oblique is flattest 30 deg out
Answer: Diff types of astig
◉ Ocular - cornea . Spec dc - corneal via 0.05k diff = 0.25dc
Answer: How do you work out the residual astig
◉ Assess va, cover le start with + side
Answer: How to preform an over refraction
◉ Increase bc
Answer: If lens fits steep?
