CL Care and Maintenance

Question 1

FDA Group 1

Answer 1

Low water content, non-ionic

Question 2

FDA Group 2

Answer 2

High water content, non-ionic

Question 3

FDA Group 3

Answer 3

Low water content, ionic

Question 4

FDA Group 4

Answer 4

High water content, ionic

Question 5

why do we have silicon in lenses?

Answer 5

great affinity for oxygen; increases transmissibility of oxygen to our eyes

Question 6

con of silicon

Answer 6

hydrophobic (repels charged particles and attracts uncharged particles)?

Question 7

what lens does not belong into any of the FDA groups?

Answer 7

Dailies Total 1

Question 8

ionic lenses

Answer 8

charged and attracts oppositely charged particles

Question 9

1234
LHLH
NNII

Answer 9

fda group mneumonic

Question 10

Fluorine advantage to lenses

Answer 10

attracts water and keeps lens moist; reason why we choose lenses with Fluorine

Question 11

What filter makes staining easier to visualize?

Answer 11

wratten filter

Question 12

why do we need to rub the lens?

Answer 12

! Rinsing alone does not detach adherent/penetrating fungi
! Micro-organisms are not the only ‘concern’
! other lens contaminants also require removal
! finger-borne contaminants (←lens handling)
! inevitable surface deposition needs to be contained
! a clean lens is usually more comfortable
! Lens wettability is enhanced


Question 13

is unpreserved normal saline ok to use for lens care?

Answer 13

no

Question 14

Any process that kills or eliminates transmissible agents

Answer 14

sterilization

Question 15

The killing and/or the removal of some or all resident pathogenic organisms

Answer 15

disinfection

Question 16

The killing, and/or the inhibition of growth, of selected micro-organisms

Answer 16

preservation

Question 17

WHAT IS A CLEANING SOLUTION?

Answer 17

Contains cleaners which are ionic or nonionic surfactants.
EDTA may be used to enhance microbial activity of the preservatives and soften the water by removing ions which also enhances the cleaning activity.
Mild abrasives may be added Opti-Free.* Usually not meant for use in the eye. Visibly tinted e.g., Boston Advance

Question 18

daily cleaner function action

Answer 18

Emulsify or solubilize contaminants and/or loose foreign matter on lens surfaces

Question 19

WHAT IS A SURFACTANT?

Answer 19

A surfactant cleaner lowers surface tension and emulsifies lipids, oils and other materials.
Prophylactic daily use to prevent deposits.
Rub vs No Rub (Mechanical cleaning vs Rinse only)

Question 20

uncharged molecule

Answer 20

lipids anchor onto hydrophobic lens or epithelium and consequently brings water with them

Question 21

WHAT IS AN ENZYMATIC CLEANER?

Answer 21

• Effective in removing proteinaceous coatings.
• Proteolytic enzymes (breaks down protein bonds)
• Papain (papaya-based enzyme/meat tenderizer)
• Pancreatin (hog pancreas derived enzymes protease,lipase & amylase)
• Subtilisin (extracellular enzyme produced by B. licheniformis)

Question 22

ENZYMATIC PROTEIN REMOVERS PANCREATIN

Answer 22

! Protease (protein), lipase (lipid) and amylase (polysaccharides)
! Pig pancreas derivative
! Cleaning efficacy similar to papain

Question 23

ENZYMATIC PROTEIN REMOVERS

SUBTILISIN A & B

Answer 23

! Proteases
! Derived from Bacillus bacteria 
! Low toxicity; used in food products
 ! Less specific binding characteristics 
! May be more effective than papain

Question 24

WHAT IS A SOAKING SOLUTION?

Answer 24

Maintains hydration, prevents contamination from microorganisms, helps maintain a clean surface by solubilizing debris
Usually not meant for use in the eye

Question 25

WHAT IS A PRESERVATIVE?

Answer 25

Inhibit all microbial growth Maintain the number of micro-organisms below a certain (safe) level Act as a LCP ‘defence system’ Must be: compatible with ingredients, CLs, & container non-toxic & non-irritating stable over time effective against a broad spectrum of organisms Preservative free vs disappearing preservatives