Soft contact lenses Flashcards
Powers of spherical CLs and increments
+6 to -6 are in 0.25D
Beyond +/-6 it is in 0.50D steps
When do we do spherical equivalence
When cyl is -0.75 and below
What powers do most manufactures produce for cylinder
From 0.75 to 2.25 in 0.50D steps
What if cyl is -1.00,-2.00,-2.50
ROUND DOWN
Axis increments ?
10 degree increments from 10-180
Characteristics of a good fit (SOFT CLS)
Corneal coverage
Lens centration
Alignment (not indenting conjuctival vessels)
Comfort and vision
How much corneal coverage for soft CL?
Extends 1mm past limbus
How much movement should be seen with blink ?
0.25 to 0.50 mm w/ blink
How to document push up test
Easy push up (smooth/easy)
Recenters easily
What to consider for lens selection
-Power (VERTEXTED)
-Base curve (relate k readings to CL BC)
-Diameter (Check HVID)
Questions to ask for contact lens follow up
-Problems, issues, concerns
-Max WT, WT today, days a week?
-Comfort and vision
-Solution / case replacement
-Lens replacement
-Sleep?
-Swim?
-Sauna?
How to clean soft CLs?
-Wash hands (moisutirzation free soap)
-CONCAVE UP / put solution on lens and rub for 5-10 seconds and then rinse with solution
-FILL CASE WITH FRESH SOLUTION
DO NOT TOP OFF SOLUTION
How often to change CL case?
Every three months / or when you finish your solution bottle (WHATEVER IS EARLIER)
How long to let CLs sit in clearcare
At least 6 hours
When checking the fit of soft CL in keratometer how does it appear if it is tight
BLURRY CLEAR BLURRY
When checking the fit of soft CL in keratometer how does it appear if it is LOOSE
CLEAR BLURRY CLEAR
is a 8.3 BC for a steep, avergae or flat cornea
steep
is a 8.5 BC for a steep, average or flat cornea
average
is an 8.7 BC for a steep, average or flat cornea
flat
How to imrpove a lens with inadequate limbal coverage
select a larger diamter contact lens
how to improve a lens w excessive movement
verify that the lens is not inverted
-select a steeper radius of curvature
-select a larger diameter
how to imrpove a lens with inadequate movement
-select a flatter radius of curvature
-select a smaller diameter
how to imrpove a lens with poor centration
-verify that the lens is not inverted
-select a steeper radius of curvature
-select a larger diameter
how to imrpove a lens that is uncomfortable for pt
asses the movement and adjust accordingly
-assess for edge fluting and change to a different brand of lenses if present
-select a lens with a lower modulus
Soft BC parameters
between 7.9 to 8.9
BEFORE INSERTING FOR SOFT CL WHAT DO U CHECK
IF IT IS THE CORRECT WAY
