Soft CL Care Flashcards
What is the aim of Soft CL Care?
· Reduce number of microorganisms that accumulate on lenses w/ wear
· Minimise risk of infection w/ CLs
· Cleaning solutions can also improve comfort by conditioning & wetting lens surface
What are the challenges for CL Solutions?
· CL solutions are subjected to extensive testing before being approved for use
· They are tested for their ability to protect against several organisms
o Pseudomonas aeruginosa (lens-associated keratitis)
o Serratia marcescens (non-ulcerating keratitis and endophthalmitis)
o Staphylococcus aureus (leading cause of microbial keratitis, about 25% of cases)
o Candida albicans (yeast infections, including corneal infections)
o Fusarium solani (common fungus in the developed world)
MRSA (methicillin-resistant Staphylcoccus aureus) – CL solutions have varying degrees of efficacy
· Acanthamoeba (amoeba) – found in tap water, very stubborn to kill in their cyst form.
o CL solutions have varying degrees of efficacy.
o Good compliance helps – not using tap water, not swimming in lenses especially when traveling
What must all solutions have in common?
· Sterile, stable at room temperature – don’t want something that needs to be stored in fridge
· Harmless (relatively) to eye if accidentally instilled
· Have no adverse effects on contact lens materials
· Compatible with any other solutions – e.g. work together with dry eye drops
· Self-sterilising – so solution in bottle while open remains sterile – need to look at sell by date & how long solution can be open for
What are the 3 steps to cleaning soft CLs?
- Cleaning
- Rinsing
- Disinfecting/storage
Describe the cleaning step in soft CL care?
· To clean debris from lens
· To reduce deposit build up
· Important to include lens ‘rub’ step in cleaning regime to mechanically remove debris & deposits (oils, proteins, ‘biofilm’)
o Take lens out, place in palm of hand w/ few drops of solution, w/ pointer finger rub lens in the solution
· Surfactant (surface-active agent) used to clean lens – think of this like the soap to clean the soap
· Composed of both hydrophilic & hydrophobic ends in molecule structure
· Hydrophobic ends cluster around debris to form micelles. The free hydrophilic ends are then able to react with water, & the micelle can then be whisked off the lens surface
· Effective against lipid & inorganic deposits, but have limited effect against bound or denatured proteins (use protein removers)
· Also enhance lens wettability
· Examples (think of this as the soup):
o Poloxamer
o Tyloxapol
o Propaline glycol
Describe the rinsing step in soft CL care?
· To clear debris away that has been dislodged by cleaning
· Prior to disinfection
· This can be done w/ MPS (multi-purpose solution) or sterile saline
Describe the disinfecting step in soft CL care?
· Not everything comes off in the cleaning & rinsing steps
· Step required to neutralise all microbes that may be present on the CL
· Different disinfectants take different lengths of time to disinfect – must check labelling on solution bottle (could be 6hrs or 8hrs)
· Typically, this is done overnight (or ideally once (one night) a week for extended wear)
· Also refers to keeping the solution in the bottle safe, not just the lenses
· 3 terms associated with antimicrobials:
1) Sterilisation – solution is sterile i.e. no organisms can survive, they have all been killed off. BUT solution does not sterilise lenses
2) Preservation – preservatives present in solution that prevent growth of micro-organisms in bottle – keeps it sterile
3) Disinfection (also refers to solution in bottle not just CLs) – reduction of level of micro-organisms to a level that is safe for ocular surface w/o damaging the CL. This occurs in the CL case à using a preserved sterile solution to achieve a disinfection
· Examples of biocides (destroy life) used in CL solutions:
1) PHMB (polyhexamethylene biguanide)
2) PAMB (polyaminopropyl biguanide)
3) PQ-1 (polyquaternium-1)
4) MAPD (myristamidopropyl dimethylamine)
5) alexidine dihydrochloride
Describe multi-purpose solutions (MPS)?
· Most convenient & common design of SCL solution i.e. all parts of care regime are in 1 bottle
· Used for cleaning, rinsing and disinfecting
· Research showed that except for some fungal isolates, MPSs performed adequately (99.9% viability reduction) on FDA test-panel organisms
· Most of CL companies have various MPS options available – often multiple, e.g. one for sensitive eyes etc
o So do some of the multiple high street companies
· Coopervision – ‘All in One Light’ – for sensitive eyes
· Alcon – ‘Opti-free’ à express, replenish, & pure-moist
· Bausch & Lomb – ‘Biotrue’-has pH balance to match tears so doesn’t cause irritation, ‘ReNu’
· J&J – ‘Acuvue RevitaLens’ – “effective for all wearers”
· Menicon – ‘MeniCare Soft’, ‘SoloCare’
Give an example description of how to use MPS?
· This is an e.g. from Bausch & Lomb. Be familiar with what is available in your practice & advise pxs appropriately:
· Place at least 3 drops of MPS on each side of lens surface & gently rub for 20 seconds (some solutions may advise 30 seconds)
· Thoroughly rinse each side of lens for 5 seconds w/ MPS
· Place cleaned CLs in lens case & fill w/ fresh MPS. Soak at least 4 hours. Remember to always use fresh solution – discard solution from lens case after each use.
· Your lenses are now ready to wear. If any debris remains on CLs, rinse w/ MPS prior to insertion.
· Storage: If not wearing CLs immediately, store them in a closed lens case. Do not store your lenses in simple saline in place of multi-purpose solution. Saline solution will not disinfect. Lenses may be stored in the unopened case until ready to wear, up to a maximum of 30 days (some are not as long as this – READ your solution
Describe hydrogen peroxide CL solution?
· Very different to MPS
· Hydrogen peroxide has broad antimicrobial activity (highly effective against all micro-organisms when used in a 3% conc)
· Destroys pathogens by oxidation, which results in protein denaturation, & damages microbial cell membranes
· Preservative free
· Requires a catalyst to neutralise the hydrogen peroxide (convert it to water) during disinfection (platinum disc or tablet)
· Disinfection normally takes at least 6hrs (overnight recommended) – to insure full neutralisation of hydrogen peroxide
· Possible improvement in CL comfort w/ this system
· Company
o Bausch + Lomb – EasySept
o Alcon – AOSept
o Coopervision – Refine One Step
o Oxysept
Describe the steps to Hydrogen Peroxide cleaning when removing lenses?
· Basket type lens case rather than flat case
· This is Coopervision’s guide to 1 step hydrogen peroxide system. Be familiar with what is available in your practice & advise pxs appropriately
· When removing lenses:
1. BEFORE handling your contact lenses wash and rinse your hands thoroughly, then dry
2. Remove lens from RE & place into right basket (marked: R) of open lens holder. Carefully close the basket. Remove lens from LE, place into left basket & close it carefully
3. Thoroughly rinse each lens while in lens holder for 5 seconds w/ fresh 1 step peroxide solution.
4. Fill lens case up to marked line w/ fresh 1 step peroxide solution. Do not underfill or overfill lens case.
5. Place lens holder inside lens case & close cap securely (do not overtighten). The solution will start to bubble. Ensure lens case is in an upright position & that your lenses are fully immersed.
6. Allow your lenses to soak for at least 6 hours or overnight prior to applying onto eyes. Do not shake lens case or turn it upside down during disinfection process
STORE HYDROGEN PEROXIDE SOLUTION AWAY FROM CHILDREN & OTHER CL WEARERS WHO DO NOT USE HYDREOGEN PEROXIDE
What are the steps to hydrogen peroxide cleaning when inseting lenses?
- When inserting lenses:
- BEFORE handling your CLs wash & rinse your hands thoroughly, then dry
- Only after a period of at least 6 hours of neutralization, open cap & take out lens holder
- Lenses can be rinsed w/ sterile saline prior to insertion
- After applying your lenses onto eyes, discard all used, remaining 1 step peroxide solution from lens case, & leave it open to air dry
If storing the lenses for more than 1 day, they must be disinfected again before wear
STORE HYDROGEN PEROXIDE SOLUTION AWAY FROM CHILDREN & OTHER CL WEARERS WHO DO NOT USE HYDREOGEN PEROXIDE
WHat are alternative hydrogen peroxide steps (i.e. using a tablet)?
- If neutralisation is w/ a tablet, not a disc e.g. Oxysept solution
- Fill Oxysept® Cup to fill line w/ Oxysept® Disinfecting Solution
- W/ dry hands, remove 1 Oxysept® Neutralizing Tablet (enzyme neutralising) from blister card, drop into solution & immediately place lens holder containing lenses into Oxysept® Cup.
- Tighten cap. Gently turn Oxysept® Cup upside down, then right side up 3 consecutive times to wet upper surfaces of cup & inside of cap. Make sure tablet is in the solution. Oxysept® Neutralizing Tablet will colour the solution pink
- You must still soak your lenses for a minimum of 6hrs after addition of Oxysept® Neutralizing Tablet.
o Will see a few bubbles or some light bubbling.
o If tablet immediately begins to bubble vigorously, causing foam to form on solution surface, the tablet is neutralizing the solution too quickly for disinfection to take place
What will happen if hydrogen peroxide is not left to neutralise?
- Stinging
- Burning
- Lacrimation
- Corneal damage
- NaFl staining:
o Widespread, toxic epithelial appearance, over entire cornea – uncountable no. of dots on cornea, usually confined to epithelium as pxs will usually know straight away that they did a step wrong & will take lens out - Advise pxs that if lens ever does sting when put lens in – take it out straight away & rinse eye with saline & come in and see you – take few days off lenses w/ lubricating drops to let everything heal
o USEFUL TO ASK PX TO EXPLAIN THE INSTRUCTIONS BACK TO YOU – to double check everything has been conveyed
Describe CL case care for MPS?
- Not just about the lenses
- When lenses are removed, case should be emptied of current solution (no topping up)
- Case should then be rinsed out w/ MPS solution or sterile saline (not water)
- Make sure no residual lens solution is allowed to dry on case, shake lens case after rinsing
- Then lens container & lids should be left to air dry face down on a clean tissue before lid is put back on (no towels)
- Lens case should be replaced ideally every month
