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Flashcards in CL Care and Maintenance Deck (25):
1

FDA Group 1

Low water content, non-ionic

2

FDA Group 2

High water content, non-ionic

3

FDA Group 3

Low water content, ionic

4

FDA Group 4

High water content, ionic

5

why do we have silicon in lenses?

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

6

con of silicon

hydrophobic (repels charged particles and attracts uncharged particles)?

7

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

Dailies Total 1

8

ionic lenses

charged and attracts oppositely charged particles

9

1234
LHLH
NNII

fda group mneumonic

10

Fluorine advantage to lenses

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

11

What filter makes staining easier to visualize?

wratten filter

12

why do we need to rub the lens?

! 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

13

is unpreserved normal saline ok to use for lens care?

no

14

Any process that kills or eliminates transmissible agents

sterilization

15

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

disinfection

16

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

preservation

17

WHAT IS A CLEANING SOLUTION?

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

18

daily cleaner function action

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

19

WHAT IS A SURFACTANT?

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)

20

uncharged molecule

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

21

WHAT IS AN ENZYMATIC CLEANER?

• 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)

22

ENZYMATIC PROTEIN REMOVERS PANCREATIN

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

23

ENZYMATIC PROTEIN REMOVERS
SUBTILISIN A & B

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

24

WHAT IS A SOAKING SOLUTION?

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

25

WHAT IS A PRESERVATIVE?

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