CL (Solutions) Flashcards
CL Care: Why?
- Minimize infections & other ocular complications (Giant Papillary Conjunctivitis, Superior Limbic Keratoconjunctivitis, Sensitivity reactions, Corneal infiltrates & ulcers)
- Maintain good comfort & vision
- Maintain diagnostic lenses
What are infections ocular complications
- Giant papillary conjunctivitis
- Superior Limbic Keratoconjunctivitis
- Sensitivity reactions
- Corneal infiltrates & ulcers
All CL care products, including solutions, disinfection units, & CL cases are required to undergo review by _________ before they can be sold to the public
Food & Drug Administration (FDA)
Solution undergo testing in following areas
Chemistry
Microbiology
Toxicity
Clinical evaluation
Chemistry: Solution stability
- pH, salinity, viscosity, etc
- Breakdown of chemical components
- Sterility
- Shelf life
Chemistry: Interaction with CL materials
- Affect lens parameters
- Discoloration
- Absorption
kills rates for bacteria & fungi
Microbiology
kill organisms by simply placing the lens in solution
Disinfecting solutions
require a regimen including cleaning & rinsing to kill sufficient organism
Disinfection systems
Disinfecting solutions must be effective against what bacteria
- Pseudomonas aeruginosa
- Staphylococcus areus
- Serratia macescens
Disinfecting solutions must be effective against what fungi
- Candida albicans
- Fusarium solani
Reduction of inoculum of bacteria
At least 3.0 log units within recommended disinfection time
Reduction of inoculum of fungi
- At least 1.0 log unit within recommended disinfection time
- No increase at 4 times the minimum recommended disinfection time
Disinfection system must have the following efficacy
- 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
Disinfection systems: Microbial growth rates during solution storage
- 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
interaction with living tissues (Animals, In vitro), human testing
Toxicity
clinical research trial using groups of real patients
Clinical evaluation
at least 60 subjects for 3 months for new products
Clinical evaluation
at least 30 subjects for 1 month for roughly equivalent products
Clinical evaluation
FDA Approval
- Product
- Marketing claims
- Labeling
- Advertising
Components of Lens Care
- Hand washing
- Cleaning
- Disinfection
- Conditioning
- Rewetting
- Protein removal
- Lens case care
best way to prevent spread of infectious diseases
Wash hands
before and after handling lenses & examining px
Wash hands
most bacterial contamination of lenses is from the _____
hands
Wash hands: With soap
- Special soaps formulated for CL wearers
digital rub removes microogranims, proteins, oils, debris on the lens
Cleaning
Use of surfactant, solvent, and abrasive cleaners
Cleaning
Cleaning: ______ is an important step - removes up to 90% of surface debris
Rinsing
Cleaning: Even “_____” solutions require rinsing
“No-rub”
Reduction of microogranisms as described above
Disinfection
Disinfection: _______ is the time required to kill 90% of an organism
D-value
reduces risk of ocular infections
Disinfection
not the same as sterilization
Disinfection
soaking solutions and some cleaners
Disinfection
RGP lens surface require ______ to maintain adequate tear layer
Conditioning
Wetting agents & viscosity agents
Conditioning
Usually performed by disinfecting solutions
Conditioning
In eye drops that hydrate soft lenses & recondition RGP lenses
Rewetting
help reduce dry eye symptoms
Rewetting
helps remove surface debris
Rewetting
_____ causes blurry vision, discomfort, ocular complications
Protein
All lenses still require periodic replacement
Protein removal
separate step or during disinfection
Protein removal
Enzymes, Ionic compunds
Protein removal
Lens case: Case is an often overlooked source of contamination called
Biofilms
Clean & rinse case after lens insertion
Lens case
______ is an often overlooked source of contamination
Case
Allow case to air dry each day
Lens case
Lens case: replace case every _____months
3-6 months
What are the Solution Properties (POV)
- Osmolarity
- pH (Hydrogen ion concentration)
- Viscosity
Tonicity of the team film = 0.9% NaCl equivalent
Osmolarity
Osmolarity: Tonicity of tear film
0.9% NaCl equivalent
Solution must be within a range of 0.7 to 2.0% to prevent stinging
Osmolarity
Osmolarity: Solution must be within range of ______ to prevent stinging
0.7% to 2.0%
pH of tear film
7.4
Solution pH must be between
6.6 and 7.8