Download - Care and maintenance of soft contact lenses
CARE AND MAINTENANCE
OF SOFT CONTACT
LENSESAmrit Pokharel
Outline of the presentation Why care for contact lenses? Deposit and types Lens care regimen
Components of lens care solution Functions Steps in lens care and maintenance Types of disinfectants Do-s and Don’t-s
Purpose of Care and Maintenance Failure to prescribe proper lens care
regimen Failure of compliance
Reduced comfort Reduced vision Increased risk of contamination---
complications/ infections Dissatisfied patients
Coverging to Failure of CL wear
Outline of the presentation . Deposits and Types .
. . . . .
Deposits and Types “…Any lens surface coating or matrix
formation which is not flushed or rinsed from a lens by tears during blinking”
Types of deposits: External
Eye make-up, air pollutants, etc. Internal
Tear components-protein, lipid, mucin, etc
Contact lens Deposits How do deposits form on contact lens
surface? Interaction between lens and content of tears
Evaporation of tears leaves residue on lens
Lens chemistry attracts tear film constituents( proteins, lipids, mucin, calcium)
How do protein deposits get denatured?
Lipid deposits
Jelly Bumps
Purpose of Care and maintenance Clean lenses:
To prevent/minimize deposits
To maintain hydration and wettability
To provide comfort and clear vision
To prevent or reduce the risk of ocular infection/inflammation
Deposit complications Reduced visual acuity Lens dryness- proteins repel water and
the lens may dry up more easily Irritation and reduced comfort
shortened wear time Cause allergic response
Micro-organism’s attachment to deposits may cause eye infection
Outline of the presentation . . .Lens care regimen
Components of lens care solution Functions Steps in lens care and maintenance Types of disinfectants Do-s and Don’t-s
Components of Care and Maintenance Daily cleaner Rinsing solution Disinfecting solution Protein removers Lubricating/rewetting
solution Lens storage case
Compliance Vs Non-Compliance Simple system and Instruction
Better compliance Easy convenient
Complicated SystemConfusionNon-complianceLens wear complications
Essential Steps of Care and Maintenance Cleaning
Rinsing
Disinfecting
Extra Steps
Protein Removal Lubricating/Rewetting
Daily cleaning and/or rinsing removes majority of Micro-organisms
Essential Steps of Care and Maintenance Cleaning . . .
Daily cleaner- Functions To remove
Loosely bound foreign matter Cell debris Mucus, lipid , protein Cosmetic or other surface contamination
Majority of micro-organisms
Daily cleaner Composition Surfactants Buffers Osmolality adjusting agents Preservatives Water
Surfactant Cleaners Remove deposits by
Interacting with deposits Displacing deposits from lens surface
Emulsify oils and lipids
Destroy/dislodge micro-organisms
Prepare lens for rinsing and disinfection
Daily cleaner procedures Wash the hand Place the lens in the palm of the hand Place 2-3 drops of cleaner on each lens
surface Rub with forefinger for about 10-15 sec
per side using to and fro and circular action
Rolling the fore-finger in both directions Clean lens periphery Rinse well
Daily Lens Care Procedure
Hand washing Reduced bio-
burden
With water-based soaps
Often forgotten step
Rubbing the lens 10-15 sec on
each side To and fro action Removal of
environmental and protein deposits
Reduces risks of infection
Consumer’s perception of No Rub Simply put the lens into the case after
removal No digital cleaning, No rinsing Simple, carefree, convenient lens care Reduced usage of lens care solution
Essential steps of Care and Maintenance . Rinsing . .
Rinsing Wash off loosened
debris
Decrease risk of deposit related problems
Essential steps of Care and Maintenance . . Disinfecting .
Disinfecting system Kill or Deactivate potentially pathogenic
organisms including Bacteria Fungi Viruses Amoebae
Maintains lens hydration— stable parameters
Disinfection Store the lens for
at least 4 hours in FRESH solution
Decrease the risk of infections
Types of Disinfection Heat
Thermal UnitMicrowave
ChemicalOxidative
Hydrogen Peroxide Chlorine
Cold chemicals Various disinfectants
Thermal Disinfection Original form of disinfection-
discontinued in the market
Procedures Clean and rinse lenses Place lenses in fresh saline in lens case Heat to 70-80 deg for 10-12 min After heat cycle, allow lenses to cool before
use
Thermal disinfection Advantages
Short disinfection cycle times
Highly effective antimicrobial action
Low risk or allergic reactions
Disadvantages Incompatible with
some lenses, eg. High water content; may cause discolouration and deformation
Increased protein deposits( cook the protein) and causes allergy
Suitable power may not be always available
Chemical Disinfection
Chemical Disinfection Disinfection achieved by the presence of
preservatives Thimerosal, Chlorhexidine, Sorbic acid
Disinfection depends on the concentration and type of preservative
Preservatives are potential irritants though rare
Chemical Disinfection Actions vary in modes:
Cell membrane disruption- Benzalkonium chloride
Enzyme Inhibition-Thimerosal Protein Coagulation-EDTA
Cold chemicals Thimerosal, Chlorhexidine, Sorbic acid,
ATAC, Isopropyl alcohol, Polyquad, Dymed, Phenylmercuric nitrate
Modern Chemical Disinfectants Used in Mutipurpose (All-in-one )
solutions: Polyaminopropyl biguanide (PABA,
PHMB) Quaternary-ammonia (Poyquad) & Aldox
Multipurpose solutions Single bottle of solution for cleaning,
rinsing, disinfecting and removing protein
Advantages Simple, convenient, easy transport Enhanced safety due to lower toxicity and
complications Does not cause protein denaturation Improved compliance
Disadvantage Small incidence of mild sensitivity reactions
Hydrogen peroxide Advantages
Preservative free- theoretically less allergy
Effective disinfection
Disadvantages Inflexible
neutralisation time( lens must be fully neutralised before use)
H202 concentration decreased rapidly (3% to 1% in <10 min)- decreased anti-microbial efficacy
Not suitable for all lens types??
Hydrogen peroxide step systems
Hydrogen peroxide step systems
Antimicrobial efficacy A battery of tests is carried out to make
out the anti-microbial efficacy of disinfecting solutions: One million (6 log units or 106)
microorganisms (CFUs) permillilitre are added to the test solution)
The USP Preservative Effectiveness test requires a solution to decrease microorganisms by 3 log units ( or 1000) after 14 days and no subsequent regrowth for a further 14 days.
Antimicrobial efficacy A battery of tests is carried out to make
out the anti-microbial efficacy of disinfecting solutions: To pass as a disinfectant FDA’s Office of
Medical Devices imposes two additional requirements on an agent: At least 14 days, the original solution is
rechallenged by a 105 CFU/mL inoculum and the solution must again cause a 3-log reduction in micro-organisms over the following 14 days
The solution must be fungistatic to yeasts and fungi during the 28-day test.
Lens care regimen and deposit types Protein deposits
Chemical disinfection
Hydrogen peroxide is preferred
Proteolytic enzyme weekly
If thermal is necessary, low heat
Advise non-ionic and low water content material
Lipid deposits Thermal
disinfection Avoid
chlorhexidine-because it increases surface hydrophobicity and allows lipid adhesion
Enzyme cleaning with a lipase
Avoid FDA Group I and II materials
Lens care regimen and deposit types Calcium deposits
Thermal disinfection
Hydrogen peroxide( low pH dissolves calcium)
Proteolytic enzyme may help
Avoid tight fitting lenses
Prescribe glyceryl methyl methacrylate (CSI) material lenses.
Calculi Lipid solvent
cleaner Lipase-containing
enzyme In-eye lubricants
in EW lenses and clean more frequently
Tears with potassium deficiency worsen calculi problem so prescribe potassium sorbate solutions
Lens care regimen and deposit types Rust spots
Consider thermal disinfection
Hydrogen peroxide disinfection systems may make them less obvious
Discoloured lenses Discard the lens
as far as possible Smokers usually
get lenses discoloured due to nicotine interactions
Usually a/w protein deposits so consider the steps for the protein deposit management
Hyrogen peroxide
Lens care regimen and Dry eyes Dry-eyed patients
Dilute the saline by 20-50% with boiled distilled water. This temporarily increases the water content of the lens which is then slowly released onto the eyes.
Avoid thermal disinfection as far as possible
Dry-eyed patients Use in-eye
lubricants frequently
Re-soak the pair for 15-30 min during the day
Cosider protein removal frequently as protein deposits are usual.
Refit with low water, non-ionic materials.
Choice of Lens Care SystemSCL Heat MPS Hydrogen
Peroxide
Group I √√√
Group II
Group III
Group IV
Bleaches colour in cosmetic contact lenses
Recommendations Discard solution everyday Rub and rinse step is essential with
combination solution Keep nozzle closed Narrow openings Clean and rinse well Soak for recommended time
Essentials steps of Care and Maintenance . . . Extra steps- Protein Removal
Protein Removers Effectively remove protein deposits Have NO effect on most other deposits React by breaking protein molecules For heavy depositors
Protein removal procedure Use regularly after daily wear and rinsing
step
Lenses should be soaked in enzyme, dissolve in solution/saline for 15 min or overnight depending on the manufacturer
Lenses should be thoroughly rubbed and rinsed again afterwards
Essentials steps of Care and Maintenance . . . Extra steps - Lubricating/ Rewetting
Rewetting or Lubricating Drops Alleviating signs of dryness and
discomfort Flushing irritation particles from eye and
CL Rehydrating lens
Care for Lens Cases Scrub with tooth brush using cleaning
solution weekly Rinse with saline or disinfecting solution Air dry upside down Replace case regularly
Wash your hands before handling contact lenses
Check the position of lenses before insertion
Cosmetics/Make-ups
Put contact lenses in After applying
hair products like hairspray
Before applying cosmetics especially eye makeup
Instruction for makeup Insert the lenses before applying makeup
Remove the lenses before taking makeup off
Avoid harmful or Irritating Fumes while the Lenses Are On
Do Rinse the Lenses Always before inserting the lens and after
removing it from the eye
Rinse the lens with contact lens solutions suggested by contact lens practitioners/optometrists
Clean and change the solution in the case daily
Keep the contact lenses either in your eyes or in your lens case
Do not let hair spray or other cosmetic aerosols come in contact with the lenses
Avoid Long and Dirty Nails
Do not swim with contact lenses if yes with swimming goggles only
Don’t sleep with contact lenses Remove the lenses before going to sleep
Your cornea may not get the necessary oxygen* while asleep
*Continuous wear lenses or Extended wear lenses with High Dk can be used upon practitioner’s recommendations
The following have interactions potentially hazardous to CL wear: Tetracycline Rifampin Preserved products Aspirin Antihypertensives Tricyclic antidepressants Antihistamines Anticholinergics
Additional Tips for Hygienic CL Wear Do not mix solution types and brands Never soak/store lenses in saline or tap
water Don’t put solutions and lens case in the
toilet or refrigerator Don’t touch the tip of any contact lens
solution Don’t use any topical eye drops while
wearing.
Immediate contact with ECP If the eyes get red and irritated or if you
feel any pain remove the lenses and contact eye care practitioner
How to avoid infection Deposits can be avoided by maintaining
a good lens care regimen Cleaning Disinfection Following the instruction Shorter is better-Disposables, small
packs of solution (120 ml or 360 ml rather than 500 ml)
Why disposable? More comfortable Healthy More hygienic Convenience of spare pair at hand Longer wearing time Contact lenses related infection and
complication are on the low in disposables.
Methods Fifty consecutively presenting patients
form each of two teaching clinics who had presented for routine after-care examinations, and had undergone at least two previous after-care visits were surveyed in the study.
The contact lens teaching clinics were at the Queensland Institute of Technology and the University of Melbourne.
Carried out by the students under the supervision of optometrists.
Methods Patients in this survey had been wearing
contact lenses for an average of 2.6 years( range 0.25 to 8 years). Most wore lenses 7 days per week and 8 to 14 hours per day.
Only patients wearing daily wear lenses were included; 82% wore soft lenses and and 18 wore hard lenses
82%
18%
Lens Distributionsoft lenses Hard Lenses
Strategies to bolster compliance Strategies to improve patient
compliance must address these basic causes, and are usually considered in four classes:1) Education, so that the availability of
correct information is maximized.2) Improved communication techniques, so
that information is provided in a brief, clearly categorised and specific way( usually using more than one medium to emphasize the importance of key areas. Use of visuals is instrumental
Strategies to bolster compliance Strategies to improve patient
compliance must address these basic causes, and are usually considered in four classes:3) Organisational procedures, so that the
cost, complexity and nature of recommended care systems are tailored to the specific needs of individual patients. The example could be the use of an MPS which aims to promote patient compliance.
4) Behavioural modifications: The use of verbal or written commitments by contact lens patients.
How to enhance compliance? Educate staff and the patient
o Simple written and verbal instructionso Reinforce few key points many timeso Practical demonstration/visuals
Review lens care at every visit Keep patients coming back for more
o Compliance packs/offerso Recall systemo Regular contact through mailers
Summary Minimal adverse reactions achieved by:
Clean, well-fitted lenses Adequate physiological performance Appropriate choice of care system Regular monitoring of patients Patient compliances
References: F. Stapleton, A. J. Phillips and G. A.
Hopkins. Chapter 4 ‘ Drugs and solutions in contact lens practice and related microbiology’ in Contact Lenses, 4th Edition, Butterworth Heinemann, 1997
IACLE Contact Lens Course, Module 5, 1ST Edition, The International Association of Contact Lens Educators, 2000
References: Shovlin J: Systemic Medications and their
interaction with soft contact lenses. Int Contact Lens Clin 17: 250, 1990
Kristine D. OD, Lakshman N. Physical Properties of Soft Contact Lens Solutions.Optometry and Vision Science 2007;85:122-128
Edward S. Bennet and Barry A. Weismann, Clinical Contact Lens Practice text book, Chapters 25, 34 and 35
Thank You!!!