Unit 1 Flashcards

(49 cards)

1
Q

Types of advanced contact lenses

A

-high astigmatism toric
-high powered plus or minus
-multifocal
-extended wear
-cosmetic tint
-costume, theatrical and prosthetic
-RGP, sclera, hybrid
-myopia control and ortho k

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2
Q

when were glass contact lenses made and how they feel and who created it?

A
  • late 1880s
    -Adolf gaston eugene fick
    -low comfort and high rates of hypoxia due to lack of oxygen
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3
Q

What did Dr Feinbloom introduce

A

Patented plastic lenses in 1936
PMMA introduced later that year (greater comfort but still had issues w/ hypoxis)

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4
Q

PMMA (polymethyl methacrylate) when were they made and by who?

A

-designed in 1948 by kevin tuohy
-New plastics after the war
-Plexiglass
-Single curve design
-11.00mm diameter
Change to a bicurve in the 1950s

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5
Q

PMMA corneal lens ADVANTAGES

A

Durable
Good wettability
Good optical clarity
Can be sterilized

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6
Q

PMMA disadvantages

A

low oxygen transmission

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7
Q

When was silicone rubber developed?

A

1965

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8
Q

Advantages of silicone rubber

A

1000x more oxygen transmission than PMMA
can be moulded

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9
Q

disadvantage of Silicone rubber

A

hydrophobic
elastictiy can grab cornea
disrupts tear layer

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10
Q

What is silicone rubber used for

A

babies with congenital cataracts

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11
Q

When was RGP lenses developed

A

1974

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12
Q

RGP material : Silicone acrylate when was in developed

A

1970s

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13
Q

RGP lens materials?

A

-Silicone acrylate
-Siloxy-methacrylate monomsers
-Flourocarobs

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14
Q

Menicon O2

A

first RGP lens
Launnched in Japan in 1979

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15
Q

Polycon lens

A

“hard” lens launched in 1980 in USA
-Not an RGP lens because it was not oxygen permeable

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16
Q

excel 02

A

rgp with improved wetability in britian in 1980s

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17
Q

boston II matieral

A

-available in 1982 in USA
-future generations still used today

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18
Q

tinted RGPS

A

available in 1983 - only handling tint - did not change eye colour

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19
Q

extended wear RGPS

A

menicon EX

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20
Q

menicon EX

A

launched in 1986 in Japan
5x more oxygen permeable than menicon O2

21
Q

Flurosilicates

A

increased oxygen permeability and strength in 1990s
menicon super EX

22
Q

bicurve

A

2 radius of curvature on back side of lens
-can be used with smaller diameter lenses
-central radius and flatter peripheral curve

23
Q

tricurve

A

3 radius of curvatures
-most commonly used design
-central radius and 2 or more periphral curves

24
Q

tetracurve

A

4 radius of curvature on the back of the lens
-can be used with larger diameter lenses

25
multicurve
multiple back surface curves
26
fenestration
small hole -prevent lens adherence -increase tear movement -increase oxygen transmisibilty
27
william feinbloom
bifocal sclearal lens patent in 1936
28
john de carle
-corneal bifocal contact lens in 1957 -2 curves ground on the posterior surface -small centre distance ; surrounding near power -Simultaenous vision (most comonly lens design now)
29
constant axial edge left (CAEL)
-same peripheral edge lift regardless of central curve
30
poor candidate for RGP
lenticular astig px that are happy w soft pxs with very loose upper eyelids -dusty work enviroment
31
piggyback lenses when did it come out and what is it
1970s -soft CL under an RGP lens
32
advantages of piggyback lenses
improved comfort
33
disadvantages of piggyback lenses
2 lenses to manage/ care for lack of oxygen to cornea due to two lenses
34
saturn II - when did it come out
1977
35
what is saturn II lens
GP lens woven to a soft material Low Dk materials and very few fitting paramenters
36
when did softperm come out
1989
37
what is softperm
more parameters low Dk, tight lenses, flexure of GP portion, lens seperation at junctions
38
synergeyes - when did it come out
early 2000
39
what is synergeyes
hyperbond - prevented separation improved wetability
40
synergeyes A
astigmatism / mild kerataconus
41
synergeyes KC
kerataconus
42
synergeyes PS
penetrating keratoplasty
43
what is clearkone for
kerataconous
44
what is duette for
general myopia/hyperopia/astigmatism
45
what is ultrahealth for
kerataconous
46
what does duette progressive do
presbyopia
47
what is synergeyes ID for
SV and MF custom designed
48
candidates for hybrid lenses
1. vision fluctuation 2. pxs like the vision with GP lens but want better comfort 3. require a MF lens but vision is not adequate with a soft contact lens 4. pxs with irregular corneas 5. pxs need to correct both astig and presbyopia
49
poor candidate for hybrid
1. pxs with extremeley dry eyes (better w. scleral) 2. do not correct for astigmatism that is within the lens (correct cornea astig not lenticular)