Deposits on contact lenses - causes and prevention of occurrence. Dirt and germs have no place near the eyes! How to use lens cleaning solutions and tablets

Illustration / Photo: open source

Deposits on contact lenses bring irritation and discomfort to the eyes

There are over 140 million contact lens wearers worldwide today. One would expect that the introduction of the first disposable contact lenses in 1995 put an end to the problem of deposits on the contact lenses. Despite this, the number of objectors who stop wearing lenses every year continues to be a major concern for the industry, and discomfort associated with the use of SCLs is cited as the main reason for this.

Materials for contact lenses

Different contact lens materials attract different amounts of proteins.

1. Etafilcon A is a material with a high moisture content that attracts a relatively small amount of proteins. Most of the proteins deposited on the lens retain their active form.
2. Lotrafilcon B is a material with a low moisture content, despite the deposition of a smaller amount of protein, only a small part of them retained their activity.

Deposits on contact lenses bring irritation and discomfort to the eyes. To avoid them, it is recommended to reduce the period of wearing contact lenses. Ideal lenses and always clean are one-day lenses, but this is an expensive pleasure.

As ophthalmologists recommend, it is recommended to use the so-called monthly lenses, as on this page http://glazok.net.ua/kontaktnye-linzy/1-mesyac/. Lenses for a month - practical, cheap and safe in terms of eye health.

Structure and types of deposits

It has been proven that the quality of lysozyme affects the feeling of comfort when using contact lenses. Or rather, its active form or denatured, and not its total. The reduced content of active lysozyme is accompanied by a decrease in the level of comfort.

Protein denaturation is affected by a number of factors. The period of use of the lens, external factors, lens care solutions, or contact with certain lens materials can all cause lysozyme to lose its active state and ultimately lead to discomfort.

The denatured protein can act as an antigen and trigger an immunological response in the papillary conjunctiva, causing contact lens-induced papillary conjunctivitis.

When using traditional lenses, visual acuity is reduced due to deposits on the lenses. This problem was solved by using lenses made of modern materials frequent scheduled replacement, since when using them, the level of deposits does not reach the value at which it turns out Negative influence on visual acuity.

The nature of the deposits when using hydrogels and silicone hydrogels is completely different. Hydrogels attract more protein deposits, but the protein remains active in most cases. Silicone hydrogel materials attract more lipid deposits and significantly less proteins, most of which denature, especially at 3 or 4 weeks of SCL wear.

The introduction of a rinsing and mechanical cleaning step into the lens care regimen will significantly reduce the amount of visible protein deposits, but the mechanical friction of the lenses itself does little to remove lipids.

It would be useful to develop such care products and contact lenses themselves that would support the deposited proteins in an active state and then would not have such a negative effect on the conjunctiva.

No matter how high-quality and expensive they are, the risk of developing complications during their use is not excluded. main reason unpleasant consequences is the patient's non-compliance with the rules for using an ophthalmic product: improper storage, ignoring asepsis conditions, incorrectly selected or poor-quality solutions. In more rare cases, a complication from wearing lenses can cause a doctor's mistake - the wrong selection of a corrective product. Next, consider the most common problems when using lenses.

Corneal edema

This is the most common complication. It develops during a lack of oxygen to tissues. Such a reaction occurs when wearing low-quality lenses or falling asleep in them. It is necessary to consult with an ophthalmologist about their replacement, and also to exclude sleep in lenses.

Protein type deposits

More often, such deposits accumulate on soft lenses and, unfortunately, avoid this phenomenon impossible. However, deposits on the lenses are the most harmless complications that do not lead to serious problems.

With the accumulation of protein and other deposits (lipid or calcium), clouding of the lens surface can be noticed. Deposits lead to the formation of various roughness, which can only be seen under a microscope.

If measures are not taken to eliminate this phenomenon, deposits can cause the development of an allergic reaction, dry eyes, conjunctiva. In addition, there is a significant deterioration specifications lenses, simply, the patient sees worse in them.

Large-pallar conjunctivitis

This complication often develops as a toxic allergic reaction for the use of lenses. During the examination, you can find a tubercle on the mucous membrane of the eye.

Accompanied by a complication of increased, redness, itching. The patient complains of a sensation of having a foreign object in the eye.

Sterile ulcers. In development pathogenic microorganisms do not participate, so antibiotic therapy not required. You will need to give up lenses for a while. A doctor may recommend a short, prophylactic course of antibiotic eye drops.

allergic conjunctivitis

Conjunctivitis is common inflammatory disease eyes. This is usually not dangerous and proper treatment it can be quickly neutralized. The conjunctiva is a layer of tissue that is located at the base and extends to (the white part of the eye). It protects the eyes from damage and the penetration of infectious microorganisms.

Sometimes an allergic reaction may occur due to the wrong lens material. There is such a reaction as a classic allergic conjunctivitis: redness, burning, feeling in the eyes.

When diagnosed by a doctor of this type complications, the treatment is to stop using the lenses. To eliminate the signs of the disease are prescribed antihistamines in the form of eye drops.

One of the reasons why people refuse to wear contact lenses over time is the occurrence of various deposits on the contact lens.

One of the reasons why people over time is the occurrence of various deposits that can cause discomfort or lead to serious complications, such as, for example, papillary conjunctivitis. In the field of prevention and control of deposits, accumulated great experience, and its use helps to reduce the number of refusals to wear. In this article, we publish a detailed classification of deposits, as well as methods for their prevention and elimination. The presence of a contact lens on the eye creates a situation in which the synthetic material is in the natural environment. One of the main tasks of biomedicine in this case is to achieve right level biocompatibility.

In the field of contact lenses, correct lens design has now been developed, and as a result of the development of new technologies, materials with good biocompatibility are emerging. Poor biocompatibility causes the formation of deposits on the object or a painful reaction of the tissues in contact with it; in the case of contact lenses, it may be papillary conjunctivitis. The formation of deposits on contact lenses leads to deterioration visual perception, discomfort, inflammation, shortening the period of wearing contact lenses. A synthetic object can be considered ideally biocompatible when it and the tissues and fluids surrounding it do not have a hostile and significant effect on each other. However, so far such an ideal can only be achieved in rare cases.

The presence of a contact lens on the eye is a unique situation compared to the presence of a foreign object in other parts of the body. In this case, we have a synthetic object immersed in tear fluid while being in contact with air. The blinking process different people occurs in different ways, the same can be said about the composition of the lacrimal fluid - the set of its components can vary widely. Although the eyelid is lubricated by tear fluid, it still has a forceful effect on the substances absorbed by the anterior surface of the contact lens. AT modern world the lacrimal system in humans is not always optimally tuned; tear fluid can be affected by factors such as air conditions, computer work, diets, and the use of various medications. This effect is usually negative, so that some percentage of the population has some degree of dry eye syndrome.

Deposits on a contact lens are a type of biological boundary processes. Some features of deposits are similar to those of processes such as blood clotting and tartar formation.

Surface deposits in the form of a film

Protein deposits in the form of films are usually the result of adsorption and/or absorption of proteins such as albumin, lysozyme and lactoferrin. It is very important to remember that when proteins are absorbed into the molecular structure of a contact lens, the more proteins accumulate, the less moisture remains in the contact lens. In addition to other factors that reduce the moisture content in a contact lens, such as temperature, dehydration, pH, the contact lens loses moisture due to the absorption of proteins. Obviously, the degree of absorption will depend on the size of the protein molecules and the size of the pores of the contact lens matrix. Immediately after placing a contact lens in the eye, the proteins begin to be absorbed very quickly (this is not a process that occurs after a week or a month). Normally proteins are attracted to ionic contact lenses - positively charged amino acids are attracted to the negatively charged surface of the contact lens. Protein absorption is a one-way process, and the situation only gets worse over time. The main proteins that make up the deposits are albumin, lysozyme, and immunoglobulins. The presence of proteins on the surface of a contact lens can lead to an immune response from the palpebral conjunctiva (conjunctiva of the eyelids). Antibodies are secreted, as a result of which the papilla (papillae) increases, papillary conjunctivitis occurs.

Surface deposits in the form of fatty films usually appear more "greasy", which is to be expected from the accumulation of fats and oils. characteristic feature- a fingerprint (or something similar to it) remaining on the surface of a contact lens after touching it. Fats come from several sources. External sources can be the face and hands, they contain oily substances. Sometimes the meibomian glands can produce malformed secretions, so they should be checked for infection or inflammation. It is possible that a person has a syndrome of "dry eye" or blinking is not done completely or not often enough. Certain medications, such as oral contraceptives and diuretics, can also affect the presence of fat in tears. Fats are attracted to non-ionic lenses. Can attract fats and silicone components of contact lenses. Grease deposits can sometimes appear on contact lenses when using furniture polish sprays that contain silicones.

Bacterial contamination of contact lenses is very dangerous, because if the antimicrobial activity of tears is lower than normal, infection may occur. Bacterial and mineral (inorganic salt) deposits in the form of films are not easily recognized, and they are less common than protein and fatty films. Suffice it to say that accumulations of bacteria (or other microbes) can be in a nutrient film, which itself contributes to their reproduction. Bacteria can also accumulate near discrete raised deposits, in pits and scratches on a contact lens. As a result, cleaning and disinfection do not lead to sufficient elimination. Toxins released by bacteria can cause hostile corneal reactions. Since bacteria are always present in the eye, natural processes are quite effective in preventing their reproduction. In the new ionic contact lenses, the negatively charged hydroxyl group repels negatively charged bacteria. However, the surface of a contact lens cannot remain in a "virgin" state forever, and the resulting "biofilms" can attract bacteria. Their reproduction is accelerated when the bacterium attaches to the surface of the contact lens. Environments with hyperacidity also promote the growth of bacteria. Therefore, an increase in the content of lactic acid and carbonic acid in the lacrimal fluid leads to a decrease in pH and may affect bacterial adhesion.

New materials that reduce hypoxia and hypercapnia should be safer in this respect. This is especially important in the case of soft contact lenses, when tear exchange behind the lens is difficult. Any material that reduces bacterial adhesion will help reduce the likelihood of adverse reactions eyes. Materials that both reduce bacterial adhesion and resist bacteria are a big step forward in the search for materials for extended wear contact lenses, and can also be used in daily wear contact lenses.

We should not forget about the existence of microbes such as protozoa, as well as viruses and fungi. Fungi can grow into the matrix of the contact lens and cause degradation of the polymer, and in addition, they can be a source of fungal infection on the damaged epithelium. Inorganic (mineral) deposits in the form of films along appearance similar to protein films and are composed of insoluble components such as calcium phosphate, etc., which have not taken a crystalline form. They can affect the surface and parameters of the contact lens.

Deposits in the form of individual (discrete) spots

The morphology and composition of such deposits are as follows:
1. Base adjacent to the contact lens polymer; consists of unsaturated fatty acids and calcium, which serves as a stabilizer.
2. The middle layer, occupying most deposits, similar to a dome; consists of cholesterol, cholesterol esters and mucins.
3. Third layer, transparent; is made up of proteins.

The etiology of the process can be different. Sometimes the cause is individual chemical composition tears, dry eye syndrome, low level pH, poor cleaning of contact lenses, polymer from which the lens is made.

Large complex spots are called jelly bumps and range in size from 200 to 800 micrometers. Such deposits are extremely difficult to remove, especially when they grow into the matrix, and not just on the surface of the contact lens. They can be eliminated with the use of intensive oxidative and enzymatic cleaners, but after the contact lens is worn again, deposits form in the same places.

Such deposits can cause different symptoms. Possible weakening of vision, mechanical irritation of the palpebral conjunctiva (with concomitant follicular and papillary conjunctivitis), very rarely - minor injuries of the epithelium (if the deposit occurred on reverse side contact lens).

Plaque plaques and deposits giving a geographical pattern

Organic plaques in the form of plaques in many cases consist of several layers. Often they the inner layer formed by unsaturated fatty acids(tear fats), the middle layer consists of mucin, and the outer layer is protein.

Inorganic deposits have white color, they have clearly defined boundaries. The form is right and wrong. These deposits are visible even to the naked eye; it is believed that they consist of calcium, however, in a much more intense content than in the films. Crystalline deposits may be covered with a translucent film. Calcium, phosphate and carbonate ions accumulate on the surface of the lens, become insoluble, resulting in the formation of crystalline deposits, sometimes taking the form of granules.

Particles

The most common form of such deposits is the so-called rust spots that occur on soft contact lenses. The typical color is orange-brown. Usually one or two spots appear, the occurrence of more of them is associated, in particular, with certain working conditions of the wearer of contact lenses - for example, if he works at a lathe and his eyes are not properly protected. Iron particles usually enter the eye from the air, in some cases they are brought in by hand. If the particle is small and indented into the contact lens, then usually the eye does not react to its presence; if its size is large and it rises above the surface of the contact lens, then a feeling of discomfort may arise. Over time, the particle may fly off the surface of the contact lens, but the rust stain will remain.

Color change

Disinfectant solutions are now largely free of traditional preservatives such as thimerosal and chlorhexidine, so contact lens discoloration is less common than it used to be. In most cases, the stain covers the entire contact lens and is evenly distributed over it, only in rare cases the color is not uniform.

Brown and tan spots are usually caused by the presence of melanin and tyrosine. Nicotine can contribute to the appearance of melanin-like substances, as well as direct influence through cigarette smoke. Adrenaline and vasoconstrictors can also be the cause of this color.

Thimerosal preservatives contain mercury, which can stain the contact lens in grey colour- from light gray to dark gray. Chlorhexidine can cause yellow-green or gray-green discoloration of contact lenses, which, when exposed to ultraviolet light, begin to fluoresce.
Contact lens discoloration can be caused by medical preparations. For example, epinephrine, when oxidized, can form melanin pigments that are dark brown in color.

Mixed deposits

Earlier we discussed the individual types of deposits. However, it should be noted that not in all cases specific deposits appear on the contact lens. So, mixed fat and protein deposits can occur, and it is quite difficult to determine whether this deposit is specific or mixed.

Removal of deposits

Fortunately, a person's symptoms help to understand that deposits have appeared on the contact lens. People may complain about a reduction in contact lens wearing time, deterioration in visual perception, and a feeling of discomfort. Deposits either on the lens or inside it can reduce oxygen permeability, which leads to an exacerbation of possible hypoxia. Large deposits sometimes lead to reddening of the eye - due to mechanical irritation and/or inflammatory reaction.

Cleaning the surface of a contact lens using surfactants is mandatory operation for lenses that are not disposable contact lenses. If a contact lens is to be reused, it must be cleaned and disinfected. Some users omit the cleaning procedure, especially people using care systems that use hydrogen peroxide.

Cleaning a contact lens with your fingers using a surfactant cleaner is designed to remove loosely attached deposits - mucin, bacteria, waste products, and other substances such as undenatured proteins - from the surface of the contact lens. The accompanying removal a large number microbes contributes to more effective disinfection. Wiping a contact lens with a surfactant cleaner and then rinsing thoroughly afterward plays a huge role in contact lens hygiene. Some cleaners are alcohol based and therefore more successful at dissolving organic materials. Enzymes have been used for many years, and there are cleaners that claim to remove proteins and fats. However, not all types of proteins and fats are equally affected by them. We also note that deposits such as jelly-like bubbles are rare in our time, due to the popularity of contact lenses for frequent planned replacement.

If it was possible to determine the type of deposit, it is worth choosing contact lenses made from a different material. For example, if the deposit is proteinaceous and the contact lens is made of an ionic material, then a non-ionic lens should be tried. Conversely, if the deposit is fatty, then perhaps the best option there will be a replacement of non-ionic material with ionic. If the contact lens has changed color, then this problem can be solved in several ways - for example, by placing the contact lens in a 3% hydrogen peroxide solution for several hours. If a protein is involved in the stain, then removing it can weaken the stain. In some cases, nothing helps at all, it remains only to replace contact lenses and prescribe a care system that does not use traditional preservatives.

While it's impossible to completely reduce the chance of deposits, following the tips above will help reduce contact lens refusals caused by deposits.

Prepared by Vadim Davydov based on the article "Contact Lens Surface: Properties and Interactions" (Optometry Today. 1999. July 30); the online version of the article is available at www.optometry.co.uk; the illustrations from the press releases of the company "Ciba Vision" were used in the design; Eyelid #8(52)

Eyes - the most important body feelings. Their health determines a person's ability to receive information from the outside world.

Decreased visual acuity - actual question, which is successfully solved with correct selection medical optics.

The use of contact lenses and glasses significantly improves the quality of life. BUT proper hygiene - the key to maintaining eye health.

Can contact lenses be cleaned at home?

Exist the following types cleaners for contact optics:

Cleansing with Enzyme Tablets

Principle of operation: during the operation of contact lenses (CL) on their surface protein deposits are formed, which are poorly cleaned even good solution for lenses. In this case, you should use special enzyme tablets. The basis of the tablet is subtilisin A and mucin-plus.

When dissolved, these substances attack lipids, proteins and calcium deposits. The use of such tablets is recommended once a month.

Instructions for use:

• Take case for lenses a couple of tablets, tweezers, solution.
• Rinse container and fill it with fresh fluid.
• Place with tweezers 1 tablet in each cell container and wait for their complete dissolution.
• Put your lenses in the container screw on the lids tightly and leave for the period indicated on the package.
• After the time has elapsed, remove the lenses, clean them like daily wear.
• Discard the used solution out of the container, rinse it and fill in new. Put lenses in there. few hours.

Peroxide cleaning system

Peroxide systems are solutions containing 3% hydrogen peroxide essence, acting as an oxidizing agent, stabilizers-phosphates and sodium chloride, as well as a neutralizer that allows the use of such a system no harm for eyes.

Photo 1. One Step peroxide cleaning system in a 360 ml bottle, Sauflon.

Solution affects bacteria, fungi, viruses, microorganisms, which makes it indispensable for people who use lenses for a long time, as well as for owners of sensitive eyes. According to the method of neutralization of hydrogen peroxide, one- and two-stage purification systems are distinguished.

One-step and two-step enzymatic methods

Neutralizer at one-stage speaks titanium disc placed in a special container (sold with the solution).

Place the lenses in the appropriately labeled compartments of the container. Pour the solution to the circle line and screw the cap on tightly. Leave a minimum of 6 hours.

After the time has elapsed, remove the products, pour out the contents of the container and rinse his.

Put it on in a warm and dry place to dry.

Important! Do not leave liquid in the container.

two stage the method is intended for deeper purification of CL. The neutralizer is not only a titanium disk, but also enzyme tablet. The instruction is identical to that of the one-step method.

Pros and cons of the tool

Advantages:

• Impact on pathogenic microflora, fungi, viruses.
• The system is hypoallergenic, as it does not contain preservatives.
• Provides deep cleaning.
• Effectively disinfects the material.

Flaws:

• The system is not suitable for lenses with high rate hydrophilicity.
• After a day, the solution becomes a breeding ground for bacteria and microorganisms, which contributes to the development of eye infections. Therefore, if the residence time of contact optics in solution exceeds 1 day, additional cleaning is required.
• Additional treatment with conventional multifunctional solution may be required.
• High price.
• If the container is lost or damaged, processing is not possible.

How to clean CL correctly

The use of any optic obliges a person take better care of hygiene visual organs. To avoid unpleasant consequences from wearing CL, you should remember the list simple rules:

1. Before eye contact hands should be well washed and dried under a stream of air, or wiped with a lint-free towel.
2. It is forbidden rinse neither container nor lenses running and distilled water.
3. Wearing time CL is limited by the manufacturer. Expired or damaged products should not be worn.
4. Use fresh every time multipurpose solution. Repeated use may lead to infectious diseases.
5. Not recommended to wearin acute respiratory diseases.
6. If there is an infection visual organs, wearing contact optics is strictly prohibited.
7. Apply makeup after putting on lenses, and wash off makeup after removing them.
8. Can't swim or dive in open water and pools.

Important! The presence of any adverse reactions(feeling foreign body and dryness) reason to see an ophthalmologist for other lenses.

Ophthalmologists note that the most common reason for patients to refuse to use contact lenses is the risk of various deposits forming on their surface. It is known that they can cause discomfort and even provoke various diseases. What types of deposits exist and why are they dangerous?

The ability to correct vision with lenses has become a real salvation for many people. However, it is important to understand that these optical products are foreign object for visual organs. Manifested defensive reaction — increased secretion tear fluid, the structure of which is often disturbed under the influence of various circumstances, for example, prolonged work at a computer or exposure to the cornea elevated temperatures. In addition, during blinking, an additional load is placed on the lenses, which contributes to the accumulation of certain particles on their surface. What types of deposits can accumulate and what harm can they do to the original structure of the lenses and our visual organs?

Protein deposits

The first variety, which we will talk about in this article, is protein, or, as they are also called, protein. As a rule, the main substances of this group that form deposits are lysozyme, albumin and immunoglobulins. Accumulating on the surface of contact lenses, they form a kind of thin film. It is important to understand that the more proteins are involved in its formation and the denser it is, the lower the initial level of hydrophilicity of the optical product becomes. The lenses most susceptible to protein deposits are those formulated with ionic polymers and FDA Groups III and IV. The accumulation of protein on the surface of optical products can lead to the development of papillary conjunctivitis, an inflammatory pathology of the mucous membrane of the eye.

lipid deposits

The next category of deposits that form on contact lenses are lipid or fatty deposits. They got their name due to the fact that, accumulating on the surface of optical products, they resemble a fatty-oily layer. A prime example This type of deposits can be called a fingerprint that remains on the lens after you rub your eyes inaccurately. In addition, lipid deposits can also form under other circumstances, for example, if you do not blink often enough or suffer from a violation of the secretion of the eye glands. AT increased amount lipids begin to build up on lenses if the wearer has dry eye syndrome. To provoke an increased formation of lipids can also be taken by some medicines such as diuretics or oral contraceptives. If we talk about the varieties of contact lenses that are most prone to the accumulation of fatty deposits, then these are optical products made of non-ionic polymers, as well as optics containing silicone in their composition.

Bacterial deposits

The most dangerous, according to experts, types of deposits that can accumulate on the surface of contact lenses are bacterial. In most cases, they "accompany" protein and lipid deposits, as they provide a nutrient medium for reproduction. Bacteria can accumulate in places where lenses are damaged, for example, in the thinnest scratches that are invisible to our eyes. In addition, toxins that negatively affect the condition of the cornea can also contribute to this. That is why it is very important to ensure timely care of ophthalmic products with the help of special disinfectants. The accumulation of bacteria while wearing contact lenses can cause various infectious diseases visual organs. The most common types of bacteria today are gonococci and staphylococci. Their presence on the surface of the lenses, as a rule, causes conjunctivitis or amoebic keratitis.