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!!!