CONTACT LENS UNIT 2

Question 1

Indications for GP and hybrid lenses

Answer 1

-Needs excellent VA/shaprness
-Custom designed lenses
-Borderline and mild dry eyes
-Irregular corneal surface
-Poor VA w/ gls and soft lenses
-Vision fluctuation w/ soft toric lenses
-High myopia, hyperopia, astigmatism
-ortho k

Question 2

Contraindications for GP and hybrid

Answer 2

-Occular inflammation
-allergies
-pingecula/pterygium
-corneal hypothesia (loss of sensitivity)
-poor lens handling/cleaning/maintenance
-immunosuppresion
-dust/chemical vapors
-sensitive to foreign body sensations
-pregnanacy

Question 3

What are the main benefits that patients receive from RGP lenses

Answer 3

Can cover corneal astigmatism
better clarity
better for mild dry eyes
more oxygen to the eye

Question 4

What are some benefits for the practice that are associated with fitting RGP lenses

Answer 4

-less required storage space
-develop a strong raport with the px since they will need to come back often for folow ups

Question 5

Low dk - RGP

Answer 5

25 to 50 (Daily wear and myopes)

Question 6

high DK for RGP

Answer 6

51 TO 100 (daily wear and hyperopes)

Question 7

hyper Dk for RGP

Answer 7

100 (Extended wear)

Question 8

refractive index for flurosilicone acrylate

Answer 8

1.42 to 1.46

Question 9

8 material properties

Answer 9

-wettability
-friction
-oxygen permebility
-oxygen transmission
-refractive index
-modulus (Flexure of lens)
-luminance transmission
-surface hardness

Question 10

6 RGP physical parameters

Answer 10

-power
-diameter (large diameters are better comfort)
-base curve (radiuscope)
-centre thickness
-peripheral curves
-edge profile

Question 11

lens designs

Answer 11

-for regular corneas
-astigmatism
-kerataconus
-post surgical (oblate corneas)
-presbyopia

Question 12

characteristics of hybird lenses

Answer 12

-soft skirt
-gas permeable centre
-hyperbond junction (joins the gp centre and soft skirt together)
-tangible hydrapeg coating (makes it very slippery so hard to remove)
-overall diameter (14.5mm)

Question 13

modality for RGP

Answer 13

1-2 year replacement

Question 14

modality for hybrid lenses

Answer 14

6 month replacement (softer lens so more debris can get in there)

Question 15

how long can you wear a RGP lens?

Answer 15

start with 1-2 hours and increase over days
-MAX of 14-16 hours daily but depends on px (Ex, dry eye or allergies)

Question 16

hybrid wearing schedule

Answer 16

day 1; up to 6 hours
day 3-5; 8 hours
day 6+; as eye care professional reccomends