CL (Solutions) Flashcards
1
Q
CL Care: Why?
A
- Minimize infections & other ocular complications (Giant Papillary Conjunctivitis, Superior Limbic Keratoconjunctivitis, Sensitivity reactions, Corneal infiltrates & ulcers)
- Maintain good comfort & vision
- Maintain diagnostic lenses
2
Q
What are infections ocular complications
A
- Giant papillary conjunctivitis
- Superior Limbic Keratoconjunctivitis
- Sensitivity reactions
- Corneal infiltrates & ulcers
3
Q
All CL care products, including solutions, disinfection units, & CL cases are required to undergo review by _________ before they can be sold to the public
A
Food & Drug Administration (FDA)
4
Q
Solution undergo testing in following areas
A
Chemistry
Microbiology
Toxicity
Clinical evaluation
5
Q
Chemistry: Solution stability
A
- pH, salinity, viscosity, etc
- Breakdown of chemical components
- Sterility
- Shelf life
6
Q
Chemistry: Interaction with CL materials
A
- Affect lens parameters
- Discoloration
- Absorption
7
Q
kills rates for bacteria & fungi
A
Microbiology
8
Q
kill organisms by simply placing the lens in solution
A
Disinfecting solutions
9
Q
require a regimen including cleaning & rinsing to kill sufficient organism
A
Disinfection systems
10
Q
Disinfecting solutions must be effective against what bacteria
A
- Pseudomonas aeruginosa
- Staphylococcus areus
- Serratia macescens
11
Q
Disinfecting solutions must be effective against what fungi
A
- Candida albicans
- Fusarium solani
12
Q
Reduction of inoculum of bacteria
A
At least 3.0 log units within recommended disinfection time
13
Q
Reduction of inoculum of fungi
A
- At least 1.0 log unit within recommended disinfection time
- No increase at 4 times the minimum recommended disinfection time
14
Q
Disinfection system must have the following efficacy
A
- Reduction in all bacteria by at least 5 log units
- Reduction of each bacteria species by at least 1 log unit
- Hold fungi at stasis level throughout recommended disinfection period
- After putting inoculated lenses through the recommended disinfection regimen, the lens should not grow more than 10 colonies microogranisms on laboratory plates
15
Q
Disinfection systems: Microbial growth rates during solution storage
A
- Reduction of inoculated bacteria by 3 log units at 14 days, and of rechallenge by 3 long units at 28 days
- Maintain molds & yeasts at initial levels throughout storage time
16
Q
interaction with living tissues (Animals, In vitro), human testing
A
Toxicity
17
Q
clinical research trial using groups of real patients
A
Clinical evaluation
18
Q
at least 60 subjects for 3 months for new products
A
Clinical evaluation
19
Q
at least 30 subjects for 1 month for roughly equivalent products
A
Clinical evaluation
20
Q
FDA Approval
A
- Product
- Marketing claims
- Labeling
- Advertising
21
Q
Components of Lens Care
A
- Hand washing
- Cleaning
- Disinfection
- Conditioning
- Rewetting
- Protein removal
- Lens case care
22
Q
best way to prevent spread of infectious diseases
A
Wash hands
23
Q
before and after handling lenses & examining px
A
Wash hands
24
Q
most bacterial contamination of lenses is from the _____
A
hands
25
Wash hands: With soap
- Special soaps formulated for CL wearers
26
digital rub removes microogranims, proteins, oils, debris on the lens
Cleaning
27
Use of surfactant, solvent, and abrasive cleaners
Cleaning
28
Cleaning: ______ is an important step - removes up to 90% of surface debris
Rinsing
29
Cleaning: Even "_____" solutions require rinsing
"No-rub"
30
Reduction of microogranisms as described above
Disinfection
31
Disinfection: _______ is the time required to kill 90% of an organism
D-value
32
reduces risk of ocular infections
Disinfection
33
not the same as sterilization
Disinfection
34
soaking solutions and some cleaners
Disinfection
35
RGP lens surface require ______ to maintain adequate tear layer
Conditioning
36
Wetting agents & viscosity agents
Conditioning
37
Usually performed by disinfecting solutions
Conditioning
38
In eye drops that hydrate soft lenses & recondition RGP lenses
Rewetting
39
help reduce dry eye symptoms
Rewetting
40
helps remove surface debris
Rewetting
41
_____ causes blurry vision, discomfort, ocular complications
Protein
42
All lenses still require periodic replacement
Protein removal
43
separate step or during disinfection
Protein removal
44
Enzymes, Ionic compunds
Protein removal
45
Lens case: Case is an often overlooked source of contamination called
Biofilms
46
Clean & rinse case after lens insertion
Lens case
47
______ is an often overlooked source of contamination
Case
48
Allow case to air dry each day
Lens case
49
Lens case: replace case every _____months
3-6 months
50
What are the Solution Properties (POV)
- Osmolarity
- pH (Hydrogen ion concentration)
- Viscosity
51
Tonicity of the team film = 0.9% NaCl equivalent
Osmolarity
52
Osmolarity: Tonicity of tear film
0.9% NaCl equivalent
53
Solution must be within a range of 0.7 to 2.0% to prevent stinging
Osmolarity
54
Osmolarity: Solution must be within range of ______ to prevent stinging
0.7% to 2.0%
55
pH of tear film
7.4
56
Solution pH must be between
6.6 and 7.8
57
Solutions with pH outside this range will sting on instillation
pH (Hydrogen ion concentration
58
______help to maintain pH
Buffers
59
Solution properties: Borates, phosphates, nitrates, bicarbonates, citrates
pH (Hydrogen ion concentration)
60
thickness of a solution
Viscosity
61
Viscosity of Soft lens solutions:
low viscosity like saline solution
62
Viscosity of RGP solution
can be higher viscosity to increasing wetting & cushioning
63
Viscosity of rewetting agents
may be high viscosity
64
Solution components
- Preservatives
- Benzalkonium Chloride (BAK)
- Thimerosal
- Chlorhexidine Gluconate
- Sorbic Acid
- Polyquarternium-1 (Polyquad)
- Polyaminopropyl Viguanide (Drymed), Polyhexadine Hydrochloride (PHMB), Polyhexamethylene Biguanide (TrisChem)
- Myristamidopropyl Dimethylamine (Aldox)
- Ethylene Diamine Tetraacetic Acid (EDTA)
- Benzyl Alcohol
65
inhibit growth of microorganisms & keep solution bottles free from contaminants
Preservatives
66
also serves as CL disinfectant, present in cleaners, rinsers, & disinfectants
Preservatives
67
- quaternary ammonium
- antifungal & antibacterial
- bacteriocidal in combination w EDTA
Benzalkonium Chloride(BAK)
68
causes corneal SPK, conjunctival hyperemia & edema
Benzalkonium Chloride (BAK)
69
binding to the lens matrix can lead to toxic concentrations in the tears
Benzalkonium chloride (BAK)
70
- not used in soft lens solutions, do not use eye washes to soak or rinse soft lenses
- found in many ophthalmic drops
Benzalkonium chloride (BAK)
71
- organic mercurial
- bacteriostatic (slow acting)
- hypersensitivity reactions are common
Thimerosal
72
causes SPK, conjunctival hyperemia, irritation
Thimerosal
73
turns lenses grey
Thimerosal
74
still used in cheap saline solutions
Thimerosal
75
Biguamide antiseptic
Bactericidal
Disrupts bacteria cell membranes
Chlorhexidine gluconate
76
Toxic reaction similar to Thimerosal in soft lens wearers
Chlorhexidine gluconate
77
- binds to soft lenses
- turns lenses green
- used extensively in RGP solutions
Chlorhexidine gluconate
78
- Bacteriostatic
- Lower incidence of adverse reactions: low grade stinging
Sorbic acid
79
- Turns lenses yellow-brown
- Original "sensitive eyes" preservatives
Sorbic acid
80
- quaternary ammonium compound
- bactericidal
- large molecular weight
Polyquaternium-1 (Polyquad)
81
- not absorbed into SCL as much as others
- induces minimal tissue response
- higher incidence of subepithelial infiltrates
Polyquaternium-1 (Polyquad)
82
less likely to cause discoloration
Polyquaternium-1 (Polyquad)
83
derivatives of Chlorhexidine but more effective
Polyaminopropyl Biguadine (Dymed), Polyhexadine Hydrochloride (PHMB), Polyhexamethylene Biguadine (TrisChem)
84
- large molecules
- not absorbed into SCL as much as others
- induces minimal tissue response in low concentrations
- higher incidence of SPK
Polyaminopropyl Biguadine (Dymed), Polyhexadine Hydrochloride (PHMB), Polyhexamethylene Biguadine (TrisChem)
85
- anti-fungal & bacteria
- kills bacteria, fungi, and Acanthamoeba trophs & cysts
Myristamidopropyl Dimethylamine (Aldox)
86
penetrates cell walls, disrupts cell walls to cause cell death
Myristamidopropyl Dimethylamine (Aldox)
87
- indirect bacteriostatic agent
- chelates calcium
- ineffective when used alone
Ethylene Diamine Tetraacetic Acid (EDTA)
88
- calcium competes with preservative molecules for the active sites on the bacterial cell walls
Ethylene Diamine Tetraacetic Acid (EDTA)
89
- enhances efficacy of other preservatives, such as BAK
Ethylene Diamine Tetraacetic Acid (EDTA)
90
- bactericidal
- used in RGP solutions
- works well against biofilms, only when combined with a Surfactant
Benzyl Alcohol
91
Cleaning Agents (SASO)
- Surfactant
- Abrasives
- Solvents
- Oxidants
92
Cleaning agent: amphipathic compound (hydrophilic head, hydrophobic tail)
Surfactants
93
Cleaning agent:
- like soaps
- reduce surface tension of fluids
- facilitate removal of debris, especially lipoidal deposits
Surfactant
94
Cleaning agent: mostly nonionic bc few problems with toxicity
- Poloxamine, Poloxamer, Pluronic, Tetronic
Surfactants
95
Cleaning agent: polymer beads/other solid particles
Abrasive Elements
96
Cleaning agent: mechanically removes surface deposits, including bound protein films
Abrasive Elements
97
Cleaning agent: found in soft & rigid cleaners
- Suspension - must shake well
Abrasive Elements
98
Cleaning agent: solvent, capable of dissolving lipid deposits
Isopropyl Alcohol
99
Cleaning agent: hydrogen peroxide
- Slight cleaning action - primarily a disinfectant
Oxidants
100
increase surface wetting for better comfort, deposit resistance, and cleaning efficacy
Wetting Agents
101
What are Wetting Agents
- Polyvinyl alcohol
- Polyvinyl pyrrolidone
- Polysorbate 80
- Povidone
- Polyethylene glycol
102
increase contact time for greater wetting, disinfection efficacy
Viscosity Agents
103
Viscosity Agents: Cellulose derivatives
Hydroxypropylmethyl cellulose
104
remove surface bound denatured protein (lysozyme) deposits
Protein removers
105
- used with lenses replaced less often than once a month
- maintain clear, comfortable vision
Protein Removers
106
- enzymes cut proteins into small pieces
- available in tablet or liquid forms
Enzymatic Cleaners
107
dissolved in saline solution as a separate cleaning step or in disinfecting solution in a single step
Enzymatic Cleaners
108
Enzymatic Cleaners: Rinsing removes protein fragments
- Papain - derived from papaya
- Pancreatin - derived from hog pancreas
- Subtilisin - synthetic
109
Cleaning agent: - buffer in Alcon solutions
- negative charged
Citrate
110
ionically binds to charged protein molecules & pulls them away from lens surface
Citrate
111
- negatively charged two prolonged molecule
- found in ReNu Multi-Plus multipurpose solution (B&L)
Hydranate (Hydroxyalkyl phosphonate)
112
- competes with calcium ions that bond protein molecules together to disrupt protein films
- ionicallly carries protein molecules away from lens surface
Hydranate (Hydroxyalkyl phosphonate)
113
Allergan Complete uses the high ionic strength of potassium to ionically remove lysozyme from the lens surface
Potassium
114
Solution types
- Saline solution
- Disinfecting solution
- Multi-purpose solutions
- Conditioning solutions
- Daily cleaners
- Rewetting solutions
115
Types of Saline Solution
- Unpreserved Saline Solution
- Preserved Saline Solution
116
Saline solution: salt tablets mixxed with distilled water, no longer FDA approved
Unpreserved Saline Solution
117
Saline Solution: packages/bottles,
- Unisol: single use vials
- Unisol 4: 4 oz. bottle good for 14 days after opening
- Aerosol cans
- one way valve prevents contamination
Unpreserved Saline Solution
118
Saline Solution: preservatives included to maintain solution disinfection
Preserved Saline Solution
119
Saline Solution: shelf life once opened may be less than expiration date indicates
- important to examine expiration dates
Preserved Saline Solutions
120
Solution type: decrease bacterial & fungal load on lenses as described above
Disinfecting solution
121
Types of Disinfecting solutions
- Chemical
- Hydrogen peroxide
122
Disinfecting solutions: preserved solutions that are able to attain the disinfection efficacy defined by FDA for disinfecting solutions (not disinfection system)
Chemical
123
Disinfecting solutions: lenses must be stored in the solution for a minimum soak time (typically 4-6 hours) Solutions have maximum storage time (up to 30 days)
Chemical
124
Disinfecting solutions: some must be neutralized or rinsed away prior to lens insertion
Chemical
125
Disinfecting solutions: most current disinfecting solutions can be used in the eye
Chemical
126
Disinfecting solutions: oxidative solution that kills microorganisms, including bacteria, fungi & protozoa
Hydrogen peroxide
127
Disinfecting solutions: lenses must be soaked in solution for a minimum of 10 - 15 mins for maximum efficacy
Hydrogen peroxide
128
Disinfecting solutions: H2O2 must be neutralized before lenses are inserted
Hydrogen peroxide
129
Disinfecting solutions: H2O2 is neutralized to water & oxygen
Hydrogen peroxide
130
soft & rigid lens solution containing all necessary components for cleaning, disinfection & wetting
Multi-purpose (MPS)
131
- preservatives for disinfection
- Surfactants or other cleaners for cleaning efficacy
- wetting agents
Multi-purpose Solutions (MPS)
132
- safe to use in the eye
- may not require digital rubbing to attain sufficient cleaning efficacy
- not necessarily stand-alone disinfecting solution
Multi-purpose Solutions (MPS)
133
- rigid lens solutions containing
- preservatives for disinfection
- safe to use in the eye
Conditioning Solutions
134
- wetting agents to temporarily make the hydrophobic surfaces wettable
- usually need separate daily cleaner
Conditioning Solutions
135
solutions that facilitate removal of loose surface debris
Daily Cleaners
136
Daily cleaners removes these
- Microorganisms
- Protein
- Lipids
- Mucous
- Dirt & other environmental debris
137
contain surfactants, abrasive compounds, isopropyl alcohol, benzyl alcohol, other cleaning agents
Daily cleaners
138
- toxic to the eye
- must be rinsed prior to lens insertion
- usually performed after lens removal & before soaking
Daily cleaners
139
solutions that are used in the eye during lens wear to increase comfort
Rewetting Solutions/Drops
140
- rehydrate soft lenses
- flush debris
- contain wetting & viscosity agents
Rewetting Solutions/Drops
141
- may contain cleaning agents to help keep lenses cleaner while on the eye
- may not be packaged in bottles larger than 30 ml (sterility & handling)
Rewetting Solutions/Drops
