CARE AND MAINTENANCE OF CONTACT LENSES

MANOJ ARYAL B. Optometry

IOM,Maharajgunj Medical Campus

PRESENTATION LAYOUT

• Introduction• Overview of care and maintenance Care and maintenance of soft contact lenses Care and maintenance of RGP contact lenses Lens deposits Patient education and compliance: use and care of

contact lenses Discussion

Introduction

Most crucial aspect of contact lens wear Influence the success of contact lens wear and

patient’s satisfaction with their lenses

Overview Of Care And Maintenance

Purpose:Clean lensGood comfortGood visionSafe lens wear

Components: Cleaner

Daily cleaner

Weekly/protein cleaner

Rinsing solution Disinfecting solution Lubricating/Re-wetting solution Lens storage cases

CleanersMost common components

Surfactants(surface active agents)

Non-ionic Ionic

AnionicCationicAmphoteri

c

Buffers Osmolality

adjusting agents

Preservatives Chelating

agents water

Cationic surfactants are not normally used with SCLs bcz. They may be bind with lens particles

Preservatives are primarily used to protect the cleaning solutions from microbial contaminations after opening

Surfactant cleaners:

Normally used in conjunction with finger rubbing Rubbing step is always followed by rinsing step Rubbing: dislodges the contaminants Rinsing: removes the displaced contaminants

Daily Cleaner

Function To remove:

Loosely bound foreign matter

Cell debris Mucus,lipid, protein Cosmetics or other

surface contamination

Dailey cleanersContains friction enhancing agents/polymeric beads

These are the small solid particles that behave as a mild abrasive but which do not affect lens surface

Eg. Allergan LC 65&B&L sensitive eye daily cleaners

Extra strength daily cleaner Alcon Opti-clean,

Polycleans ii B&L Concentrated

cleaner CIBA Miraflow

General procedure: Wash hands Place lens in palm of hand Place 2-3 drop of cleaner on each lens Rub with forefinger for about 15 seconds per side

using a to and fro and fro action. Rolling the forefinger in both directions cleans the lens periphery

Weekly cleaners:Usually formulated for protein removalSometimes called enzymatic cleaners bcz.

most contains one or more proteolytic enzymes

Rinsing Solutions

Function: Removal of loosened lens contaminants Removal of residual cleaners Rehydrate lens Resolve enzyme tabs

Most common and most economical rinsing solution is saline

Saline: Isotonic saline can also be used: As a medium for enzyme treatment in some

regimens To elute unbound adsorbed or absorbed lens

contaminants To rehydrate lens

DisinfectionFunctions:

Kill or deactivate potentially pathogenic organisms includes Bacteria Fungi Virus Amoebas

Maintain lens hydration

Types Thermal Chemical

Conventional Polymeric Tablet

Hydrogen peroxide

Thermal Disinfection

High temperature kill micro-organism by:

Denaturation of cell components

Disruption of plasma membranes

DNA damage

2 methods of applying heat to lenses in a lens storage case

Wet: immersing the lens case in water at or near its

boiling point or Placing the lens case above boiling water

Dry: direct heating of lens case by a matching, snug

fitting, electrically heated device After heating cycle allow lens to cool before use

Advantages

Short disinfection cycle times(10-30)

Very effective in destroying microorganisms

Low risk of toxic or allergic reactions

Disadvantages

Incompatible with some lenses(usually SCLs)

Suitable electrical power for heat units may not always be available

Can cause lens discoloration

Increased protein deposition

Chemical Disinfection

Conventional Chemicals: Thimerosal Chlorhexidine Sorbic acid Benzalconium chloride Iso-propyl alcohol

Thimerosal: Effective as anti-fungal agent

Reduced effect when combined with EDTA

Cytotoxic to corneal epithelium

Chlorhexidine gluconate: Antibacterial agent

Leaches from Group 1 to Group 4

Benzalkonium chloride Antibacterial agent

Cytotoxic

Sorbic acid Anti bacterial with limited

antifungal activity

Not cytotoxic

Causes discolouration of lenses

Alcohol: Cleaners: isopropyl alcohol and ethanol Disinfection : isopropyl alcohol

E.g.CIBA Miraflow used in disinfecting solutions Both disinfectants and cleaners contain large

conc. of alcohol Cleaner 20% Disinfectant 17%

Chemical Disinfection: Disinfectant Sensitivity

Symptoms

Sudden decrease in ocular tolerance

Decreased wearing time(2-4 hour)

Burning, grittiness, dry sensation

Signs

Conjunctival redness

Epithelial damage

Corneal inflammation

diffuse corneal staining resultingfrom a reaction to a disinfectant or a preservative.

A mild red eye (conjunctival hyperaemia) due tosensitivity to a solution component, usually thedisinfectant.

Disinfectant sensitivity depends upon: Preservative type Preservative concentration Lens material Soaking time

Lens age Patient susceptibility

Polymeric Disinfection

Relatively recent class of disinfection Most common examples are

PHMB Polyquaternium-1

Used in multipurpose solution

E.g B&l Mps ReNu,Alcon Opti-Free,

Allergan Complete ,CIBA Solo care soft

Disadvantages

Reduced disinfecting power

Rub/rinse still required

Compliance is more important

Tablet Based System

Chlorine tablet system Halane(sodium dichloroisocyanurate) Halazone(poly(dichlorosulphanoyl)be

nzoic acid) E.g Alcon Softab, Sauflon Aerotab

Chlorhexidine E.g Optim eyes

Hydrogen Peroxide Disinfection

Along with thermal disinfection is one of the earliest SCLs disinfection method

Hydrogen peroxide: Produces free oxygen radicals which are very reactive and quickly bind to many cell

components

Decomposes to water and oxygen

Requires neutralization

Can be formulated preservative free

Can be supplied in one-step form

Must be stabilized

Hydrogen peroxide: neutralizationNon selective anti-microbial agentMinimum 3 hr in 3%h2o2 recommended

Bacteria 10-15 minFungi 60 min Acanthomoeba 3-6 hour

Neutralization:2-step peroxide disinfection1-step peroxide disinfection

Neutralizers: Sodium pyruvate:

Na2C3H3O3+H2O2=NaC2H3O2+H2O+CO2

Sodium sulphite:

Na2SO3+H2O2=Na2SO4+H2O

Sodium thiosulphate:

2Na2S2O3+H2O2=Na2S4O6+2NaOH

Sodium tetrathionate

Highly deleterious to cornea

2-step peroxide neutralization: stoichiometric(reactive) Neutralization

2-Step H2O2 Systems: Catalytic Neutralization

Have longer neutralization time

In either tablet or solution form, neutralization and equilibrium time of 10-15 minutes are generally adequate for low water content lenses

Higher water SCLs require longer times of up to 1 hour

Neutralizers:

Catalytic disc in second lens case

Catalase solution or tablet

2- Step Peroxide Disinfection

Advantages

Can vary time of disinfection

Concurrent protein removal possible

Suited to occasional wear

Disadvantages

Less convenient

Some have preserved neutralization solution

Potential for irritation

expensive

1-step neutralization system

Formulated so that the peroxide disinfection and neutralization are performed during the recommended time

With tablet using system a delay is applied to the neutralization phase

With disc-based systems, no delay is applied to the neutralization phase

When neutralization is performed as separate step, the system is called atwo-step neutralization

Disadvantages: Inflexible neutralization time

H2o2 concentration decreases rapidly(3%-1%in less than 10 min)

Not effective against fungi and acanthamoeba species

Catalytic disc needs regular replacement

Potential for irritation

Possible recontamination

In systems using catalytic disc, whenever H2O2 is in contact with the disc, the concentration is decreasing

User of disc based 1- step systems should be instructed to place their lenses in lens baskets before pouring peroxide solution into the case

If not, much of the peroxide is neutralized by exposure to the disc before lenses are immersed

H2O2: Effect On Lens Parameters

May cause reversible parameters changes in high water lenses

HWC requires longer soaking time to reverse Caution:

Discomfort and irritation follow lens insertion if residual peroxide present

No permanent damage to normal ocular tissues

Corneal staining might be observed

Protein Removers

Most protein removers are based on enzymes Enzymes cleaners work by leaving substrate specific

enzymes break down their target molecules, thereby facilitating their removal

Protease target proteins

Lipase target lipids

While amylase targets polysaccharides

Enzymes can also remove other types of deposits if they are incorporated in the protein deposits

Enzymes may also break bonds between the lens materials and proteins

Enzymatic cleaning does not replace the disinfection system

Procedure: Used regularly, after the daily cleaner and rinsing

step

Lenses should be soaked in enzyme dissolved in solution/saline for 15 min to overnight, depending upon manufacturer

Lenses should be thoroughly rubbed and rinsed again afterwards

Enzymatic protein removers

Contain one of the following Papain Pancreatin Subtilisin A &B

Papain: protease i.e. enzyme that act as protein specifically

Derived from papaya plant

Usually have a slightly unpleasant odour due to the inclusion of cysteine

Binds to contact lens material and can cause sensitivity reaction

Short 15 min soaking time possible

E.g. Allergans Soflens enzymatic cleaner or Profree

Subtilisin A&B: Proteases

Subtilisin A formulated specifically for use in hydrogen peroxide lens care systems

Subtilisin B is formulated for use in conventional chemical and thermal systems

Re-wetting/ Lubricating Drops

Used for: Promote comfort

Reduce deposit induced friction b/w eyelids and corneal surface

Rehydrates the lens

Lubricating and re-wetting eye drops are formulated with viscosity-enhancing agents(commonly polyvinyl alcohol, methylcellulose etc)

Lens Storage And Cases

To avoid contamination, lens cases should be rinsed after every use and the lenses stored in fresh solution

Acanthamoeba and other free living protozoans are especially prevalent among those using tap water for rinsinf their lens cases, using home made saline as a rinsing solution for contact lenses, or swimming with contact lenses.

Biofilm or glycocalyx formation on the surface of contact lens storage cases can horbour pseudomonas aeruginosa and serratia marcesens

Care of lens cases: Discard used solutions

Scrub with a toothbrush and detergent weekly.oil free soaps or detergents are recommended

Rinse with hot water and rub thoroughly with a clean, dry tissue

Lens replacement schedule and care regimen

Daily disposable: Does not require use of surfactant cleaner, disinfecting solution or weekly enzyme

If needed the patient can use in eye re wetting drops or sterile saline for rinsing prior to insertion

Regular disposables

Suitable care includes multi-purpose solutions

No weekly protein removal is needed

Other options: Surfactant cleaners

1-step hydrogen peroxide disinfection

Lubricating/re-wetting solutions

Care regimen guidelines for frequently replaced lenses,conventional lens wearers

In-office diagnostic(trial set) lenses SCL use heat if possible otherwise peroxide

RGP use peroxide or store lens dry

Re-disinfect non disposable inventory trial lenses at least once a month

In-office procedures Oxidising agents

Standing waves

Ultrasound

Ultraviolet

Microwave

Common oxidizing agents used are LiprofinTM, 6 or 9% peroxide

Care and maintenance

Important steps for patients

Wash hand prior to handling lenses

Rub each side of each lens for 10-15 seconds using a surfactant cleaner

Rinse each lens thoroughly in normal saline

Disinfect contact lenses in fresh disinfecting solution in a clean storage case Remember

Do not mix solution type and brands Assess patients compliance Repeat instructions and assess demonstration to patient Remind patient to clean lens case weekly

The Message

C lean

R inse

A nd

D isinfect

L enses

E very time

RGP Care And Maintenance

Purpose: Minimize deposit accumulation

Increase lens wettability

Facilitate comfort and vision during lens wear

Deposits:

RGP material containing

Siloxane are more prone to protein deposits

Fluorine are more susceptible to lipid coating

Practitioner choose low Dk over high Dk RGP material despite the benefits of higher oxygen permeability

The high Dk RGP lenses are more susceptible to lens surface deposits than their low to moderate Dk counterparts

Cleaner :

daily surfactants

Protein removers

Disinfecting or soaking solution

Wetting solution

lubricants

Daily surfactant: Similar to their SCL counterpart

An alcohol based cleaner is well suited to fluorosiloxane lenses which tend to acquire lipid deposits

Patient should be cautioned against soaking RGP lenses in alcohol based cleaner

Further, they should be adjusted to rinse their lenses thoroughly immediately after using such cleaners bcz. they have been shown to alter lens parameters if allowed to remain in contact with the lenses

Enzyme: recommended for protein removal in deposit prone wearers

Polish: may be necessary for lenses over 12-18 months old Cleaning pad; may be effective in removing some

deposits from RGP lenses Avoid:

Vigorous rubbing

Excessive pressure on lens

Prolonged cleaning with mildly abrasive cleaners

Recommended technique: Place the lens in the palm of hand Rub lens with finger for minimum of 10 seconds Rinse with saline or tap water approved for

drinking

Disinfection Although microorganisms can not readily attach to

RGP lens surfaces , they can attach to deposits RGP lens should not be thermally disinfected

As this can cause warpage Soaking time (4hour to overnight or as

recommended)

Preservatives used includes: Thimerosal Phenyl mercuric nitrate Benzalkonium chloride Chlorhexidine Poly(amino propyl bigunide) And polyquaternium-1

H2O2 IS NOT NORMALLY USED GOR RGP LENSES

Wetting and soaking: It is better for RGP lens wearer to wet-store their lenses If RGP lens are stored dry, parameters such as BOZR

will invariably flatten and the lens surfaces may not wet properly

Wet storage also improves initial on eye comfort and greatly assists microbial control of lens storage conditions

RGP wetting and soaking solution contains: Antimicrobial agents to disinfect the lenses and to

preserve the solution after initial opening

Wetting agent to improve lens wettability

Viscosity-enhancing agent to thicken the formulation

Buffer system to adjust and maintain solution pH

Salts to adjust solution osmolality

Wetting agents: Better wetting result in better vision and greater comfort Improve the wetting characteristics of the lens surface: Convert hydrophobic surface to hydrophilic Assist tear film to spread more easily and evenly on lens

surface Increase comfort on insertion

E.g. Poly vinyl alcohol, Polyvinyl pyrolidone, Polysorbate

RGP lens non-wetting areas due to: Deposits

Manufacturing process

Polishing compounds

Surface combinations

Rinsing solutions RGP lens can be inserted directly into the eye after soaking in

appropriate wetting/soaking solutions

Burning on insertion: change to a less viscous solutions

Stinging on insertion: change solution

RGP-MPS

One bottle system(OBS)

Combination of cleaning, disinfecting, and soaking functions

E.g. Allergan Total, Boston Simplicity, CIBA SOLO-care-hard

Lubricating drops:

Used during lens wear to:

Improve comfort

Clean lens surface

Maintain lens wettability

Trial Set Disinfection/Storage

RGP trial lens disinfection: the method recommended is:

Clean with alcohol-based cleaner immediately after use

Place in a clean container

Wet storage in a soaking solution when lens is not being used

Clean the storage solution periodically(monthly)

Clean lens again immediately before next use

Summery

Because of their non-absorbent nature, surface properties, rigidity and durability RGP lenses are easier to care for

Clean ,rinse and disinfect lens every time(CRADLE) RGP lens kept in use longer than SCLs

Therefore efficacious lens care area more important Consider a programmed replacement scheme

Contact Lens Deposits

Definition:

Any lens surface coating or lens matrix formation which is not flushed or rinsed from the lens by the tears during blinking. In effect, anything that remains on the surface despite blinking is a deposit

Deposit formation:

Tear protein(lysozyme) are attached to the lens

Tear evaporates and leave residue on the lens

After protein are deposited, other components of the tear film (such as mucin) may adhere to protein

Over time. Layers build up and structural changes take place(e.g. Denaturation)

Factors influencing lens deposition:

Individual difference in tears

Lens materials Care system Wearing schedule

EW might induce more deposits than DW

Environment Patient hygiene

Types Of Deposits

Teal related Protein Lipid Jelly bumps Inorganic

deposits

Non-tear related Fungi

Lens discoloration

Mercurial deposits

Cigarette residues

Surface combination

Rust spots

Protein deposits:

Are a semi-opaque or translucent film usually thin whitish and superficial

Have a frosted glass appearance

may cover lens surface partially or full

Cause the lens surface to become hydrophobic

Can crack and peel if thick

Factors favouring a build up of protein on a contact lens:

short BUT

Ionic binding capacity

Inadequate cleaning especially of the lens periphery

Altered blinking

Heat disinfection

Tear deficiency or altered tear composition

Chronic allergies and GPC

Lipid Deposits

Appears as greasy, smooth, and shiny adherent films on both RGP and soft contact lenses

Best observed between blinks Appears as a thick ,oily coating Lipids involved includes: phospholipids, neutral

fats, triglyceride, cholesterol, cholesterol esters, and fatty acids

Origin: mainly from meibomian gland

Predisposing factors: Tear film quality Slow blink pattern Poor lens compliance Careless use of inappropriate cosmetics/lotions

Jelly Bumps

Appear as a clumps of raised transluscent mulberry like deposits

Typically form in inferior, exposed portion of lens

Occur more frequently in high water, ionic, EW lenses

Predisposing factors

Quality of tear film Poor blinking Lens surface

contamination HWC>LWC Aphakia cleaning

consequences

Large and numerous jelly bumps lead to wearer discomfort

Large deposits can cause the lens to attach to the upper lid so that each blink causes excessive lens movement

When located within pupil zone-visual acuity can fluctuating

Maya also cause mechanical irritation of tarsal conjunctiva

In extreme case, may cause CLPC

Inorganic Deposits

Calcium carbonate deposits Calcium phosphate deposits Appearance: White crystalline specks Can be small or large Rough surface Penetrate lens surface if severs

Fungal Deposits

Appearance:

Filamentary growth on and into lens

Usually white, brown or black

Fungal formation

Spores on lens surface from eye or environment

Proliferates to large visible growth

Penetrate lens matrix

Contact lens good medium for fungal gruwth

Lens Discoloration

Can result from: Natural lens ageing Surface contamination Mercurial deposits

Mercurial deposits:

Appear as a greyish to black discoloration

Reuse of thimerosal containing solution is one cause

To prevent avoid mercury based preservatives

Ageing

Polymer breakdown Chemical absorption Handling Stress and strain deposition

Surface contamination Make up Moisturizing lotions Hairspray Chemical fumes

Management Advice patient on good hygiene Proper care and maintenance Do not reuse solutions Smokers should be warned

Lens Deposition :Rust spots Appearance: Small superficial

raised spots Colored orange to

black Can be few to

numerous

DISCUSSION

Importance of rub and rinse in use of multipurpose contact lens solution.

Optom Vis Sci. 2011 Aug

PURPOSE : The introduction of contact lens multipurpose disinfection solution (MPDS) that can be used in conjunction with a "no-rub" regimen has simplified lens care requirements. Once adhered to a surface, microorganisms can become less susceptible to disinfection. The aim of the study was to evaluate the effect of various regimen steps on the efficacy of MPDS when used with silicone hydrogel and conventional lenses.

RESULTS: Overall, the greatest efficacy of MPDSs was observed when "rub and rinse" was performed before disinfection with each of the microorganisms tested, regardless of lens type. "No rub and no rinse" steps resulted in a greater load of microorganisms remaining on lenses compared with the other regimens (p < 0.05). When "rinse-only" was performed before disinfection, the MPDS containing polyquad performed generally better (p < 0.05) than MPDSs containing polyhexamethylene biguanide against bacteria. Significantly, less microorganisms were recovered from galyfilcon A than from other lenses (p < 0.05) when MPDSs were used with "rinse-only" step.

CONCLUSIONS:

This study has demonstrated that "rub and rinse" is the most effective regimen and should be recommended in conjunction with all multipurpose lens care solutions and all contact lens types, particularly with silicone hydrogel lenses.

Comparative antimicrobial efficacy of multi-purpose lens care solutions using the FDA's guidelines

PURPOSE: evaluated six single-bottle, multi-purpose lens care solutions and a two component lens care system for disinfection efficacy according to the stand-alone primary criteria within the recently published U.S FDA Guidelines.

RESULTS:

ReNu and ReNu MultiPlus met the FDA's acceptance criteria for stand-alone disinfectants against all challenge organisms: Staphylococcus aureus, Serratia marcescens, Pseudomonas aeruginosa, Candida albicans, and Fusarium solani. Opti-Free Express failed to meet the FDA's stand-alone disinfectant acceptance criteria for S. aureus, S. marcescens and C. albicans and Opti-Free Express with Opti-Free Supraclens failed to meet the acceptance criteria for either S. aureus and C. albicans. Opti-One failed to meet the FDA's stand-alone disinfectant acceptance criteria for C. albicans and F. solani. Both Complete and Solo-Care failed to meet the FDA's acceptance criteria for C. albicans.

CLAO J. 2001 Jan;27(1):16-22.

Disinfection efficacy of contact lens care solutions against ocular pathogens 

PURPOSE:

Three commercially available products labeled as multi-purpose contact lens solutions, one multi-purpose disinfecting solution, and a hydrogen peroxide system were evaluated for antimicrobial activity according to the current International Organization for Standardization (ISO) and the U.S. Food and Drug Administration (FDA) stand-alone procedure for disinfecting products. One multi-purpose solution was selected to assess its antimicrobial activity against two human corneal isolates of Pseudomonas aeruginosa.

RESULTS:

ReNu MultiPlus (Bausch & Lomb, Rochester, NY), AOSEPT (CIBA Vision Corporation, Duluth, GA), and Opti-Free Express with Aldox (Alcon Laboratories, Ft. Worth, TX) were the only lens care products that met the stand-alone criteria for all required microorganisms within their minimum recommended disinfection time. Of these, ReNu MultiPlus provided the greatest overall antimicrobial activity. ReNu MultiPlus demonstrated a significantly higher mean log reduction of Staphylococcus aureus and Serratia marcescens than Opti-Free Express. ReNu MultiPlus also gave a higher mean log reduction of S. aureus and S. marcescens than AOSEPT, and a higher mean log reduction of Candida albicans and Fusarium solani than AOSEPT, Complete Comfort Plus (Allergan, Irivine, CA), and Solo-Care (CIBA Vision Corp.) (at 4 hours). Both Complete Comfort Plus and Solo-Care (at 4 hours) met the primary acceptance criteria for bacteria; however, neither product possessed enough antimicrobial activity to meet the minimum criteria for yeast or mold. ReNu Multiplus was effective against corneal isolates of P. aeruginosa.

CONCLUSION:

ReNu MultiPlus, AOSEPT, and Opti-Free Express met the requirements of the stand-alone primary criteria for disinfecting solutions. ReNu MultiPlus demonstrated the greatest overall disinfection efficacy, as well as excellent activity against clinical strains of P. aeruginosa

Contact lens care products effect on corneal sensitivity and patient comfort 

PURPOSE: To evaluate the possible effect of two leading soft

contact lens care products on corneal sensitivity, relative comfort, and superficial corneal staining in adapted disposable soft contact lens wearers.

RESULTS:

Patients habitually using OPTI-FREE Express reported higher comfort ratings than did patients using ReNu MultiPlus. On crossover, patients who initially used ReNu MultiPlus experienced similar comfort when using OPTI-FREE Express, but OPTI-FREE Express users experienced a substantial decrease in comfort when switched to ReNu MultiPlus. Esthesiometry showed significant differences in average sensitivity in favor of OPTI-FREE Express (P=0.0041). Statistical trends supported observed increases in corneal sensitivity when switching to OPTI-FREE Express and decreased corneal sensitivity when switching to ReNu MultiPlus. ReNu MultiPlus was also associated with slightly more corneal staining.

CONCLUSIONS:

ReNu MultiPlus, a biguanide-based contact lens care product, was associated with decreased comfort during midday and end-of-day periods. ReNu MultiPlus was also associated with significant reduction in relative corneal sensitivity compared to Polyquad-based OPTI-FREE Express. Disturbance to normal corneal sensitivity may play a role in contact lens-related dry eye and discomfort. Further investigation is warranted

Care and maintenance of SCLs

SCLs are susceptible to deposits due to: Lenses are covered by pre-lens film all the

times

The tear film undergoes hydration and dehydration cycle as a result of blinking and evaporation b\w blinks

Lens is a subject to atmospheric changes and pollutants

Decreased surface wettability is likely to accelerate deposition

Deposits: Complications

Irritation and reduced comfort

Reduced visual acuity

Shortened lens life

Increased potential for infection

Increased incidence of GPC