unit 6 Flashcards
what is in a GP fitting kit
-set of lenses
-single or multiple diameters
-same BVP for each lens
-BOZR in 0.1mm steps (change in 0.05mm results in 0.25D change)
how would you fit someone with smaller eyelids
smaller diameter and a steeper base curve
easy ways to take diameter?
take the HVID and subtract is by 2
how would we fit a px with lid attachement
we can fit them with an alignment fit based on their flat k
corneal astigmatism of 0.75 what would the suggested BOZR be?
fit on flat K
corneal astig of 0.75 to 1.00 , what would the suggested BOZR be
fit on flat K or 0.25D steeper than flat k
corneal asitg of 1 to 2.50 what would be the suggested BOZR
fit 0.25 to 0.50 steeper than flat k
corneal astig of more than 2.50 what would the suggested BOZR be
back surface toric recommended
WTR astigmatism
flatter curvature in horizontal meridian
no tears in horizontal meridian, verticle meridian has tear lens
ATR astigmatism
flatter curvature in verticle meridan
no tear lens in verticle meridian, horizontal meridian has tear lens
what to use on RGP before inserting
-boston simplus or conditioning solution
-wet lens thoroughly
-soack lens for 24 hours - new lenses
is digital imaging cost minimal or expensive
it is minimal once you have it set up.
digital imaging ? images are better then sketches in chart notes T OR F?
TRUE
7 exmaples of digital imaging?
- digital SLR camera slit lamp imaging system
- Smartphone digital imaging
- video slit lamp imaging system
- infared imaging (used for mibomian gland dysfunction)
- OCT anterior segment (good for scleral fitting)
- scanning slit beam tomography
- confocal microscopy
what is the average OAD/OZD
9.4 / 8.0 MM
when you increase the diameter by 0.5mm what do you do to BOZR
you will need to flatten BOZR by 0.25D
when you decrease the diameter by 0.05mm what do you do to BOZR?
You will need to steepen the BOZR by 0.25D
When you increase the diameter what does it increase?
it increases the sag depth
when increasing sag depth what fit does this result in?
a tighter fit
when you decrease the sag depth what does this do to the fit?
it will loosen the fit
T OR F - when you change the diameter of the lens it doesnt change the power of the lens but when you change the curvature of the lens this will change the power
TRUE
How to fix a continually high, not dropping after blink lens
-steepen periphery
-narrow periphery
-reduce TD
-reduce thickness
when lens is continually low/rapid drop after blink how do you fix
increase TD
reduce TC
add peripheral negative carrier
if lens is continually to one side how to fix it
increase TD
soft lens
steepen design
back surface toric design
if GP has poor comfort how do you fix it
tighten fit
reduce edge clearnece
thinner edge
remove and replace lens
modify fit
consider an aspheric or toric design
increase TD
change matieral
if you have poor vision with GP what do you do
refract and change power
asses fit and modify
toric lens
flatten fit
change material
clean lens
when you increase BOZR what does it do to the lens (mm)
flatten the lens
when decreasing BOZR what does it do to lens (mm)
will steepen lens
what is dimple veiling?
deformation of the corneal epithelium caused by trapped smalled air bubbled during CL wear // this does go away
how many mm of a ring do you want to see along an alignemnt GP lens
0.5mm ring
