CL materials

Question 1

what classifies AIDS

Answer 1

HIV + CD4 count <200

HIV+ 1 AIDS defining illness (CMV, Kaposi Sarcoma, HSK, non healing ulcer for 1 month)

Question 2

PMMA lenses

Answer 2

Dk of 0, hydrophobic, less wettable, excellent optics

Question 3

what is an advantage of PMMA lenses compared to SCL materials?

Answer 3

clearer optics

Question 4

what does a red cap on a CL solution mean

Answer 4

it should not be put directly into the eye

Question 5

what cn be measured with a radiuscope

Answer 5

BC

Question 6

hydrogel SCL

Answer 6

primarily made of HEMA. Hydopgilic lenses with adequate oxygen permeability

Question 7

siHy

Answer 7

made of silicone and water (newest technology) and are more permeable to oxygen than traditional hydrogel SCL

Question 8

conventional RGP

Answer 8

were composed of PMMA, which is hydrophobic, light weight, excellent optics, but not oxygen permeability. Rarely used today

Question 9

current RGP lenses

Answer 9

made of fluoro-silicone-acrylate. wettable, have minimal protein deposits, and have adequate oxygen permeability. Should be replaced more frequently as the Dk increases. examples of GP CLs include Boston, Fluoroperm, and Paragon

Question 10

Group 1 hydrogels

Answer 10

low water, nonionic

Question 11

group 2 hydrogels

Answer 11

hi water, nonionic

Question 12

group 3 hydrogels

Answer 12

Ionic, low water

Question 13

group 4 hydrogels

Answer 13

ionic, high water

Question 14

group 5 SCL

Answer 14

siHy

Question 15

how to remember the different FDA classifications for hydrogels

Answer 15

NNII, low high low high

Question 16

low water SCLs

Answer 16

dailies

Question 17

high water SCLs

Answer 17

extended wear

Question 18

which group of CLs gets more deposits

Answer 18

group 4

Question 19

rigidity

Answer 19

additional property of SCL that describes the stiffness of the material. it depends on the thickness and the modulus of elasticity of the CL (primarily applies to SiHy). in general, as water content increases, the modulus of elasticity decreases (SiHY becomes less rigid)

Question 20

when going from PMMA to RGP

Answer 20

stay in low Dk and then work up

-low Dk more sturdy and what they are used to

Question 21

high modulus

Answer 21

less water, stiffer

Question 22

benefits of high modulus

Answer 22

better handling

easier application and removal

Question 23

cons of high modulus

Answer 23

GPC
SEALS
Limbal epithelial hypertrophy 
mucin balls
edge fluting

Question 24

spin cast

Answer 24

the SCL is made by a rotating mold

Question 25

lathe cut

Answer 25

the SCL is made by cutting and is then ground with a lathe (diamond or laser)

Question 26

molded

Answer 26

SCL material is in a liquid state and is injected into a mold

Question 27

relative and absolute contraindications for CL wear

Answer 27

``` AIDS or any immunocompromised state corneal infection or inflammation hx of CL overwear anterior seg disease excessive dry eye irresponsible patient young children systemic conditions with poor wound healing decreased immune response monocular patients filtering bleb incomplete blinkers ```

Question 28

therapeutic CLs indications

Answer 28

``` keratoconnus or ectasia corneal abrasions/erosions (BCL) corneal distortions (GP) aniridia, occlusion to eliminate diplopia, or cosmoses (tinted or opaque CLs) reduce myopia progression (orthoK) aphakia Tx od DED (sclerale) ```

Question 29

orthoK

Answer 29

reverse geometry design that may be helpful to reduce myopia progression

Question 30

keratoconnus and CL

Answer 30

Rose K CL, GP CL, with a soft skirt GP lens piggy back on SCL

Question 31

presbyopia and CL

Answer 31

monovision, MFSCL, bifocal GP

Question 32

dry eye and CLs

Answer 32

thick traditional hydrogel lenses or siHy CL

Question 33

children and CL

Answer 33

dailies to minimize the effect of inadequate CL maintenance and cleaning

Question 34

To minimize GPC

Answer 34

dailies, clear care

Question 35

SJS and CL

Answer 35

scleral oir haptic GPCL

Question 36

extended wear CL

Answer 36

FDA approved contact lens material

Question 37

enzymatic cleaners

Answer 37

remove accumulated deposits from the surface of the CL heavy deposited, complaints of protein deposits

Question 38

instrument to measure power

Answer 38

lensometer

Question 39

instrument to measure BC

Answer 39

radiuscope or keratometer

Question 40

instrument to measure CT

Answer 40

thickness gauge

Question 41

instrument to measure OAD, OZD, peripheral curve widths

Answer 41

measuring magnifier, reticule