In the surgical treatment of cataracts, the most important step is to replace the clouded lens with an artificial lens, the role of which is played byintraocular lens (IOL).
Many IOLs are currently being offered by manufacturers and, of course, the question arises for patients – which one to choose?
Any IOL is made of a polymer material and is a combination of the optical part and haptics (elements used for fixation in the lens capsule).
There are two types of lenses: tough and soft.
- Rigid lensesnow used less and less, they belong to the first generation of IOLs and are used for extracapsular extraction surgery. For their implantation into the lens capsule, it is necessary to make an incision on the cornea with a size6-7 mm.
- Soft IOLs
Currently, the gold standard for surgical treatment of cataracts is ultrasonic phacoemulsification, which usessoft IOLs.They are made of high quality biocompatible materials that are resistant to deformation and do not cause clouding of the posterior lens capsule - this prevents the development of secondary cataracts.
- Monoblock IOLs (Acrysof IQ Alcon, Medicontour, Acrysof Natural Alcon, Rayner C-Flex, Superflex).In them, the optical and reference elements are a single structure and are made of the same type of material. This helps to avoid various complications both during and after the operation and reduces the risk of developing secondary cataracts. And the use of a disposable injector minimizes the risk of infection.
The IOL itself has, as the name implies, a rigid structure made of bioinert plastic, and its optical part occupies about 5-6.5 mm. For modern eye microsurgery, these are very large dimensions, since the larger the IOL, the larger the incision on the cornea. And this structure of the eye does not have blood capillaries, as a result of which the tissues grow together very slowly. In addition, for such a large cutsutures are required.
Such a lens serves the patient for life and does not require replacement.
The flexible structure of the IOL allows the operating surgeon to limit himself to incisiononly 1.8-2.0mm and do not suture.
The improved soft IOL support system ensures a secure fixation in the lens capsule, which makes it possible to conductnormal lifestylealmost immediately after the operation.
There is another important advantage: soft lenses allow a person to see well up close, and, as a rule, he is moredoesn't need glasses.
They have the sameprotective properties,like the natural lens, and do not "pass" to the retina UV radiation and the short-wavelength part of the spectrum (the so-called "blue spectrum"). Of course, there are various subtleties that the doctor takes into account when choosing an IOL for each specific patient: material, size, diameter of the optical part, etc.
We list the most common types of soft lenses:
- IOL with "yellow" filter.They allow you to protect the retina from the damaging effects of UV rays and the "blue spectrum", preventing the pathology of the central zone of the retina. By the way, the natural lens of the human eye also turns yellow with age in order to protect the eye from dangerous radiation.
- Aspheric IOLs (Acrysof IQ Alcon).This is a new generation of lenses that form a sharper image due to the aspherical surface and the same refractive power in all parts of the optical part. Implantation of such an IOL leads to a qualitative improvement in normal and twilight vision.
- Toric IOLs (Acrysof Toric Alcon (USA)).This type is used in patients with corneal astigmatism. They have a higher refractive power in certain areas, and the optical power is selected strictly in accordance with the parameters of the eye.
- Multifocal IOLs (Lentis Oculentis (Germany), Acrysof ReSTOR Alcon (USA)).They allow the patient to see equally well far and near after surgery due to the formation of not one, but several foci on the retina. The Acrysof ReSTOR (Alcon) lens has a unique diffractive-refractive optical part, allowing the patient to forego glasses.
The choice of an artificial lens in the surgical treatment of cataracts
always carried out individually.
If you want to be sure of an excellent result of the operation and receive treatment from highly qualified specialists, contact"First Eye Clinic".
We use only the best modelsintraocular lenses (IOL) best suited to the needs of each patient.
Book an appointment with us through our websiteget an extra discount.
An intraocular lens, or IOL for short, is an artificial lens in the form of an optical lens that is implanted inside the eye to replace the cloudy natural lens during cataract surgery.
In the eye, the lens acts as a lens, focusing light on the retina. Before the invention of artificial lenses, after cataract removal, patients could see well only in very thick glasses with plus glasses.
Today, the choice of modern artificial lenses is so great that not even every ophthalmologist surgeon knows about all existing models. That is why this review article is intended to help potential patients figure out which artificial lens should be chosen in a particular case.
Hard and soft intraocular lenses
The fundamental difference between IOLs is the material of the lens, due to which they are all divided into two types - hard and soft. All over the world, when removing cataracts, the seamless low-traumatic operation - phacoemulsification, which is performed through a micro-incision, has become the gold standard. In order for a fairly voluminous lens to be inserted through an incision of no more than 2.5 mm, its shape must change. Rigid lenses do not change shape, this is only available to soft lenses that can be rolled up into a tube and then injected into the eye using a special injector. Inside the eye, the IOL expands on its own and is securely fixed, thanks to the latest technology.
According to the outdated method, the cataract was removed through an incision several times larger - 12 mm. Such an incision actually occupied half the circumference of the cornea. The cloudy lens through it succeeded entirely, and a rigid lens was installed in its place. Then stitches were applied, which were removed only after six months.
Spherical and aspherical artificial lenses
The aspherical shape of the intraocular lens means that at any point on the surface of the IOL, the light falling on it will be refracted with the same force, both in the center and along the edges. This is especially important at dusk and darkness, when the pupil is maximally dilated. The advantage of these lenses is the minimization of glare (glare) in the dark from light sources. For example, from the headlights of oncoming cars, which is incredibly important for the safety of both motorists and pedestrians. Aspheric lenses also offer better contrast and color reproduction.
The spherical shape of the IOL implies different refraction of light in different parts of the lens surface - in the center of the lens, as well as along the edges. The resulting light scattering negatively affects the quality of vision - there is an effect of glare and light.
Multifocal and monofocal IOLs
If all your life, you have not had any special vision problems, you know how great it is to see equally well at any distance - reading a book, working at a computer or looking into the distance. Until a cataract developed, your lens was clear and elastic. He could easily tune (changing the curvature) to the desired distance. Upon reaching the age of forty, presbyopia set in, and the lens gradually lost its elasticity, which means it lost the ability to focus at close range.
Why these explanations? You probably guessed it - it's about artificial lenses. They are made of synthetic material and cannot change curvature by adjusting to different distances. This is the negative side of monofocal IOLs. Such lenses are designed for good vision at long distances, and for work at close range, after the operation, it is necessary to pick up plus glasses.
But there are also multifocal lenses. This is the most modern, and therefore the most expensive type of IOL. After implantation of such lenses, the patient can easily see at all distances - near, far and at medium distances without the use of other means of correction (glasses). For this, special complex optics is used in the design of the lens, in which different areas of the lens surface are responsible for vision at different distances. To achieve the optimal calculation of these zones is very costly and difficult. That is why the price of multifocal IOLs remains the highest so far.
Astigmatism correction with toric IOLs
If your vision has been less than ideal throughout your life due to astigmatism, then you have probably used special astigmatism glasses with cylinders. Do not be surprised, but modern lenses are perfectly able to correct this problem.
It is worth recalling that astigmatism is an anomaly in the shape of the cornea, as a result of which the image is distorted, like a curved mirror. When a cataract is removed from a person with astigmatism and a standard artificial lens is implanted, his astigmatism will remain unchanged. So after the operation, he will again need cylindrical glasses.
Today, fortunately, this no longer happens, because there are toric IOLs. The required cylinder is already built into these lenses, and by placing such a lens inside the eye, the patient receives an absolutely normal, without astigmatism, image. Toric IOLs require particularly complex preoperative calculations and are selected strictly individually for each patient. As you may have guessed, their cost is also slightly higher than conventional intraocular lenses. According to patients who have had astigmatism, toric IOLs give particularly good results. After the operation, people enthusiastically say that they have never had such excellent vision.
Multifocal toric intraocular lenses
The final in the line of models of modern IOLs are toric multifocal intraocular lenses. If a patient with astigmatism, after cataract surgery, wants to see far and near without glasses, then he needs just such an artificial lens.
It doesn't take much thought to realize that multifocal toric IOLs are the most expensive of all. When buying them, the patient pays for comfort, excellent quality of vision and the special complexity of individual lens optics calculations.
Light filters in the IOL
It is no secret that the natural lens of the eye has unique protective properties that can block harmful solar radiation, preventing it from damaging the retina. Today, almost all artificial lenses have an ultraviolet filter. Premium IOL models are stained with specific yellow pigments to achieve maximum resemblance to the natural human lens. Such filters cut off blue light that is harmful to the eye, which is in the invisible part of the light spectrum.
Prices for artificial lenses
The cost of intraocular lenses implanted during surgery to replace a clouded lens depends on a number of parameters:
- IOL manufacturer: domestic or foreign (USA, Germany, UK, etc.)
- Specific lens model: mono- or multi-focal, toric and other parameters.
- Prices, which are determined by a specific eye clinic (based on the pricing of the organization). Often, the cost of the operation is low, but the profit is included in the price of the IOL.
Thus, the patient can find out the final price for the IOL and its model only after a preoperative examination and an in-person consultation with an ophthalmologist who will perform the lens replacement surgery.
The cost of the most popular IOL models in Moscow
|
Lens model and manufacturer |
Prices (in rubles) |
| Hydro-Sense Aspheric (Rumex Ltd, UK) | 10 000 |
| Akreos Adapt AO (Bausch&Lomb, USA) | 15 000 |
| AcrySof IQ Natural (Alcon, USA) | 25 000 |
| AcrySof Restor (Alcon, USA) | 50 000 |
| AT LISA 809M (Carl Zeiss, Germany) | 55 000 |
| Acrysof Restor Toric (Alcon, USA) | 70 000 |
Now that you have got acquainted with most of the information that a patient with cataract needs to know about artificial lenses, it probably became clear why the cost of the operation is so affected by the type of lens chosen for implantation. "MNTK named after Svyatoslav Fedorov" - a large ophthalmological complex "with 10 branches in various cities of the Russian Federation, founded by Svyatoslav Nikolaevich Fedorov. Over the years of its work, more than 5 million people received assistance.
"Institute of Eye Diseases named after Helmholtz"- the oldest research and medical state institution of ophthalmology. It employs more than 600 people who provide assistance to people with a wide range of diseases.
The history of intraocular lenses began in the UK. It was there that the world's first operation to implant an artificial lens was performed, and it was there that the first IOL was invented. The author of the development is military surgeon Harold Ridley. Even during the Great Patriotic War, he noticed that glass fragments from the cockpit of military aircraft, falling into the eyes of pilots, behave quite stably: they do not cause rejection, they remain motionless for a long time. The material from which the glass was made - plexiglass - it was decided to use in the production of IOLs. The first lens was made by the British company Rayner, which is still operating on the market today.
However, technology has advanced, and Rayner is far from the only manufacturer of IOLs today. The market has expanded significantly. Ophthalmologists recognize the USA as the leader of the ophthalmic artificial lens market. It is there that production is most developed, there are a large number of companies, and it is from there that innovative solutions and developments come. Among US companies, Alcon stands out with its line of AcrySof IOLs (flexible lenses that can minimize aberrations, protect against UV rays and provide excellent near and far vision. According to statistics, more than 25 million of these lenses have been implanted in the last 12 years alone). Also known and recognized as quality leaders are Baush+Lomb (premium IOLs), Medennium Inc. California (premium-class IOLs, developers of so-called "gel" lenses that straighten out in the eyeball under the influence of temperature), Abbott Medical Optics (in production they focus on the accommodating properties of IOLs).
Do not lag behind American colleagues and European developers. The recognized European leader today is Germany. In this country, IOLs are produced by such giants of the ophthalmological market as Carl Zeiss (the LISA line deserves special attention: these lenses are suitable for almost any patient - the pupil size does not matter for the operation and adaptation of the implant), as well as Human Optics (the most popular model is ASPIRA, aspherical lens with a yellow filter in the middle price segment).
The British company Rayner is also considered one of the market leaders. A special invention of the company is the "improved rectangular edge" of the lens, which helps to avoid side effects after surgery, reduces the risk of secondary cataracts. This manufacturer also focuses on the IOL material: Rayner lenses contain 26% liquid and are suitable even for allergic patients with sensitive eyes.
In Europe, the Dutch manufacturer VSY Biotechnology (premium aspherical lenses) and the Swiss Staar (posterior chamber phakic lenses, the company is famous for its high-precision toric lenses) are also known.
Recently, developers from Japan have been “catching up” with Europe and the USA. Hoya Surgical Optics, for example, competes directly with US and EU manufacturers. She has been involved in ophthalmic development for over 25 years, with the first Hoya IOL introduced in 1987. Hoya Surgical Optics is distinguished by the fact that it uses the latest developments and materials in the production of IOLs, the company is included in the top 100 most high-tech in the world. The lenses of this manufacturer are distinguished by a special design - monoblock two-component. IOL support elements (their tips) are made of polymethyl methacrylate by simultaneous polymerization, which gives excellent opportunities for fixing and centering the IOL in the eyeball. This design also simplifies the process of implantation and "folding" and then "unfolding" the lens on the eyeball.
Russia also has IOL manufacturers. One of them is Latan. The company operates mainly in the domestic market, as well as in the neighboring countries (CIS). Production began in 1996. The company's line includes 40 modifications of intraocular lenses, while they are quite affordable.
Despite the fact that there are recognized market leaders, in each case, the choice of an intraocular lens should not depend on the brand or history of the manufacturing company, but on the indications. Only a specialist after a comprehensive examination can determine exactly which IOL is right for you. There are practically no identical IOLs from different manufacturers, but each of them has its own pros and cons, contraindications and risks of side effects.
The lens of our eye is a natural biconvex lens that is designed to focus light rays on the retina. One of the most common ophthalmic diseases is cataract - clouding of the lens. At the moment, the only effective way to treat cataracts is surgery, in which intraocular lenses are implanted.
Purpose of intraocular lenses
The natural lens serves as a lens that focuses light onto the retina. With a cataract, the masses of the lens begin to become cloudy, worsening the quality of vision. In the past, people with cataracts could only restore their vision with glasses with very thick plus lenses or uncomfortable contact lenses. At the moment, the clouded lens can be replaced with an intraocular lens without harm to the visual system.
Intraocular lenses (IOLs) are optical lenses that are implanted directly into the eye in place of the clouded lens or in front of it. IOLs are used not only to treat cataracts, but also to correct refractive errors. Fitting a lens helps correct high astigmatism, nearsightedness, and farsightedness.
Intraocular lenses were invented by the British optometrist Harold Ridley. At one time, this was a breakthrough in ophthalmology and made it possible to restore vision to patients with cataracts of varying degrees of maturity, relieving them of the need to wear glasses. The first IOLs weren't perfect, but over fifty years of research have made lenses that are safe, flexible, and reliable.
The success of surgical treatment largely depends on the selection of an artificial lens. Many patients ask questions: how safe is the operation, can the lens be rejected, how to choose lenses and what will be the result of the treatment. It must be understood that not all intraocular lenses are created equal. Only a qualified ophthalmic surgeon can choose lenses based on the individual parameters of a particular patient.
IOL classification
There are phakic and aphakic IOLs. Phakic lenses are designed to correct refractive errors, they are implanted without removing the "native" lens. Aphakic lenses are used in the treatment of cataracts to replace the clouded lens. Intraocular lenses can be spherical or aspherical. For spherical surfaces, the curvature of the surface is the same in all zones, while for aspherical ones, the radius of curvature varies from the center to the periphery, which reduces distortion and provides good contrast sensitivity.
Phakic and aphakic lenses are divided into anterior chamber and posterior chamber, but phakic anterior chamber lenses can only be spherical. Phakic posterior chambers are also toric, allowing you to correct myopia and astigmatism at the same time. In the treatment of cataracts, aphakic posterior chamber IOLs are usually used. Anterior chamber is considered only in difficult cases.
Aphakic lenses are divided into monofocal and multifocal, accommodative and toric. Aphakic monofocals provide good near or far vision. Toric IOLs are designed to correct astigmatism. Multifocal and accommodating, although they improve vision at all distances, are not suitable for everyone and not always. Multifocal, toric and accommodating models belong to the premium class. However, you need to understand that the premium class in this case speaks more about the complexity of manufacturing and cost than about quality and safety.
IOL manufacturing materials
Polymethyl methacrylate was the first material from which intraocular lenses were made. Today, different lenses are used: hydrophobic and hydrophilic acrylic, silicone and others. In Russia, acrylic is predominantly used, although when comparing different models, the result of the operation is the same in the vast majority of cases.
IOLs are made from polymeric materials that are strong, flexible, and durable. The lenses are biocompatible with the tissues of the eye and are hypoallergenic, so after implantation, the immune system will not reject the lens. IOLs do not require replacement during their lifetime, which allows patients to pay only once for the quality of vision.
The optical characteristics of IOLs made from different materials differ little, in contrast to the safety profile. It is believed that hydrophobic acrylic lenses are the most effective in all respects. Some time ago, ophthalmologists faced the problem of clouding and calcification of hydrophilic acrylic lenses, but new models from Bausch & Lomb, STAAR, Surgical and HumanOptics are of high quality.
Silicone lenses show stability, especially in patients who do not have comorbidities. Silicone IOLs are also recommended for children. When choosing intraocular lenses, it is necessary to take into account not only the material of manufacture, but also the features of production, delivery and storage. There is an opinion that silicone lenses can become cloudy if stored improperly. Leaving the IOL package in an antiseptic environment will change the surface of the lens.
Hard and soft intraocular lenses
Phacoemulsification is considered the gold standard for the treatment of lens opacities worldwide. This is a sutureless operation, which involves the implantation of an intraocular lens through a micro-incision. To insert a lens through a 2.5 mm incision, it must be rolled up, which only applies to soft lenses. The lens itself straightens in the eye and takes the place of the lens.
Previously, cataract removal was performed through an incision up to 12 mm, which occupied half the circumference of the cornea. Turbid masses of the lens were removed entirely by installing a rigid intraocular lens. After such an intervention, a suture was applied for 6 months.
Spherical and aspherical
The elderly are subject not only to cataracts, but also to spherical aberration. After the age of 45, many begin to experience visual discomfort when driving at night, and near vision is significantly reduced. Similar symptoms can appear even in the absence of cataracts, because they are caused by a decrease in the sensitivity of the eye due to a change in the shape of the lens. Normally, this element of the eye has a spherical shape.
An aspherical lens has such a shape that when light hits any point, it will be refracted with the same force. The optical power of the lens is the same in the center and at the edges, which is important for ensuring vision at night when the pupil expands. Aspherical lenses have an important advantage: minimal glare from bright light in the evening and at night. These lenses are recommended for drivers to protect their eyes from the headlights of oncoming traffic. In addition, aspherical intraocular lenses provide improved contrast and color reproduction.
The aspherical intraocular lens mimics almost all the characteristics of a young lens. The implantation of such a lens not only improves visual acuity, but also improves its quality in the presence of high contrast sensitivity. Aspherical lenses improve the sharpness and contrast of vision, allowing older people to see like they did when they were younger.
Aspherical lenses have not yet been tested in Russia, but they are widely used in microsurgery in Western countries. Spherical lenses refract light rays with different strengths in the center and at the edges, which creates light scattering. There may be glare and glare.
Monofocal and multifocal
Healthy people see the same well at all distances. In youth, the lens is transparent and elastic, which allows you to instantly adjust to any distance, but after 40 years, most people suffer from age-related farsightedness (presbyopia). This is a condition where the lens loses its elasticity and is unable to set up clear near vision.
Monofocal lenses provide good distance vision, but for near work a person needs glasses with plus lenses. This is due to the fact that monofocal lenses are made of a synthetic material that is not able to change its shape, as a natural lens does.
Monofocal lenses are most commonly used in cataract surgery. This lens provides good distance vision regardless of the amount of light, but when working with fine details, glasses with slight correction may be required. Monofocal lens implantation is the best option for people who don't mind wearing glasses from time to time.
They are more modern. They are divided into several zones responsible for vision at different distances, which allows a person to always see well. Multifocal lenses are considered cutting edge in cataract microsurgery. These IOLs provide equally good vision at near, far and medium distances.
The complex structure of lenses causes their high cost. This is the most modern and effective type of IOL. Multifocal lenses have ultra-precise optical characteristics, due to which they focus the image at several different points at the same time.
Toric IOLs for Astigmatism Correction
Astigmatism develops when the shape of the surface of the cornea or lens changes. Patients with this diagnosis are usually prescribed glasses with cylindrical lenses, but modern eye microsurgery makes it possible to correct refractive errors by implanting intraocular lenses. It is noteworthy that with the implantation of a standard artificial lens for the treatment of cataracts, astigmatism persists.
Installing a toric lens will correct both cataracts and astigmatism. Such a lens is installed strictly according to the marks to ensure good vision. Before implanting a toric intraocular lens, the doctor must make complex calculations. Lenses are chosen individually for each patient, so their price is usually higher than the prices for conventional IOLs.
Multifocal toric lenses are the most expensive type of intraocular lenses. Multifocal toric IOLs can correct astigmatism and cataracts, and provide excellent vision at any distance.
Accommodating lenses
These lenses provide equally good near and far vision, so additional optical correction is not required. The lens is able to change its position in the eye, maintaining the normal focusing of objects on the retina. In this way, accommodating monofocal lenses mimic natural accommodation.
The only model of accommodating lenses that has been tested is the CRISTALENS IOL, developed in the USA. These lenses are recommended for those who spend a lot of time reading and working at the computer.
Lenses with protective filters
The lens of the eye has protection that blocks the harmful spectrum of solar radiation and maintains the health of the retina. Most artificial lenses have an ultraviolet filter that mimics the protective functions of a natural lens. Some studies show that the use of lenses with a protective coating reduces the perception of shades of blue in low light.
The best models of intraocular lenses are also stained with yellow pigment to achieve maximum resemblance to the natural lens. This coating blocks blue light, which is part of the invisible part of the spectrum. However, the need to block the blue color of the spectrum remains controversial, because the main danger to the retina comes from the violet part. Meanwhile, without blue color, the circadian rhythm of the body can be disturbed and twilight vision worsens.
IOL manufacturers and popular models
Rayner, which manufactured the first IOLs, is still operating, but the Americans are recognized as the leader in this niche. Alcon lenses are considered the most popular, which has produced more than 25 million IOLs in 12 years of operation. You can also highlight the company Bauch + Lomb, which produces premium lenses. The leaders in production include Medennium Inc. California with their "gel" lenses and Abbott Medical Optics, which produce mainly accommodating models.
From European manufacturers, IOLs from German companies Carl Zeiss (universal LISA line) and Human Optics (available aspherical IOLs with a protective filter) are highly valued. The British manufacturer Rayner offers lenses with improved edges to reduce the risk of side effects. Rayner uses materials suitable for patients with very sensitive eyes.
Lenses VSY Biotechnologe (Netherlands), Staar (Switzerland), Hoya Surgical Optisc (Japan), Latan (Russia) are less popular. It should be understood that there are no identical IOLs, each has its own advantages and disadvantages, which must be considered on an individual basis.
Popular IOL Models
- IOL Acrysof Single-Piece (Alcon, USA). Monoblock lenses made of hydrophobic AcrySof acrylic. These safe and hypoallergenic IOLs have a short habituation period. The risk of lens rejection, secondary cataract development and infection is minimal because it is inserted through disposable instruments.
- AcrySof-Piece IOL (Alcon, USA). Three-piece lenses for maximum vision and stability. The model is made of hydrophobic acrylic (optics) and polymethyl methacrylate (support). Thanks to flexible acrylic, the operation to introduce such a lens is less traumatic.
- IOL Acrysof Natural IQ (Alcon, USA). Aspheric IOL model, which increases not only visual acuity, but also its quality (brightness, contrast, clarity). The manufacturer promises stable vision in any light. The lenses have an additional yellow filter that protects the retina and prevents the development of macular degeneration.
- AcrySof IQ Natural IOL (Alcon, USA). The best option in terms of quality, functionality and cost. With this IOL, corneal astigmatism can be reduced or even completely eliminated. Once the lenses are in place, the patient no longer needs to wear glasses for distance vision.
- IOL AcrySof RESTOR Natural IQ (Alcon, USA). A very popular model, which is recognized as one of the highest quality and most reliable. Multifocal IOLs are used to treat cataracts and age-related farsightedness. A person gets rid of the need to wear glasses and lenses, since the optics of the IOL has a diffractive structure.
- AcrySof IQ ART IOL (Alcon, USA). These IOLs provide excellent vision quality at all distances. The multifocal model makes it possible to cure not only cataracts, but also correct age-related farsightedness and corneal astigmatism.
- IOL LISA tri 839 MP (Carl Zeiss, Germany). An aspheric model that allows you to restore even very reduced vision (myopia within -20 diopters, hyperopia within +10 diopters, astigmatism up to 3-4 diopters). The lenses provide high quality vision with minimal flare and high contrast, while the unique surface design eliminates glare.
- IOL LISA tri toric 939 MP (Carl Zeiss, Germany). Model with a yellow filter that protects the retina from ultraviolet radiation. These IOLs are recommended for patients with a high degree of refractive error. Aspherical lenses provide normal image sharpness and contrast.
- Hydro-Sense Aspheric (Rumex, UK). Folding biconvex IOL with hydrophilic structure. This model is posterior chamber, so it is suitable for cataract treatment. Aspherical IOLs are made from acrylic.
- CT ASPHINA 603P (Carl Zeiss, Germany). Aspherical monofocal model made of hydrophilic acrylic. The lens has an ultraviolet filter. The aspherical design provides aberration neutrality and negative spherical aberration. The model has the same refractive power in any area, which helps to focus the light at one point and maintain good vision near or far.
- Aspira-aAy (Human Optic, Germany). Aspheric posterior capsule lens made of hydrophilic acrylic. The IOL has a yellow filter and a sharp edge to prevent opacification of the posterior capsule and secondary cataract. The structural features of the lens make it possible to minimize optical anomalies.
- Artisan (Ophtec, Canada). Anterior chamber IOLs, which are recommended in difficult cases (contraindications for laser correction, thinning or dystrophy of the cornea, a high degree of myopia or hyperopia). The lenses are made of polymethyl methacrylate and can be fitted to a child as each pair is made to order.
Outcome
After studying the different types of intraocular lenses, it becomes clear why the cost of cataract surgery varies so much. It is necessary to take into account concomitant visual impairments, the age of the patient, his professional activities, the presence of a driver's license, and much more. When choosing an IOL, first of all, attention is paid to stability, safety and biological reactivity.
The cost of an IOL depends on its features and brand. Before the operation, the doctor, together with the patient, chooses lenses depending on the individual anatomical and optical features of the eyes. The doctor also takes into account the wishes of the patient, his professional activities and lifestyle. Usually, specialists choose an IOL that provides good near vision, but there are cases when distance vision is important for the patient (drivers, hunters, fishermen). There are lenses that allow you to see equally well at any distance, but these are expensive IOLs.
The human lens naturally has natural protective functions that allow it to neutralize the harmful effects of sunlight, other harmful light radiation, and filters the harmful parts of the light spectrum. The retina of the eye is protected naturally, which is why over time the human lens acquires a yellowish tint.
According to scientific research, the most harmful rays of the light spectrum have a length within 500 nm. Moreover, the older the person, the more harmful radiation filters his lens. For example, the lens of a 50-year-old patient will miss about 70% of the wavelengths of 400-500 nm, and at 75 years this figure will reach 25%.
It is clear that if a patient has a cataract and is prescribed phacoemulsification, then the lens will be removed, and with it the person will lose his natural filter. With age, the artificial lens will no longer turn yellow, the degree of protection will not increase.
Today, all IOLs have a UV filter that blocks light wavelengths between 200 and 400 nm. However, about 25 years ago, lenses with colored filters were invented, and the most common of them is yellow. It gives an even higher degree of protection against the harmful effects of light.
However, ophthalmologists warn that the owners of such lenses may change twilight vision. Studies have confirmed that the degree of illumination affects the formation of the hormone melatonin in the human body. Interestingly, it is produced precisely when exposed to waves of 480 nm. Melatonin is responsible for sleep, so it can be disturbed.
However, IOLs with a yellow filter can significantly improve color reproduction and image contrast. According to studies, such lenses significantly increase the clarity of vision, reduce glare. Wearers of these IOLs have a reduced risk of photophobia and cyanopsia, which can be side effects of surgery. Ophthalmologists believe that filtering out "harmful" blue spectrum light waves improves the response of photoreceptors.
Yellow filter lenses are available in both economy and premium segments.
Below we will look at examples of IOLs with yellow filters that ophthalmologists can offer you.
Acriva UD ВВ, The Netherlands
This lens mimics the natural human lens to a high degree, which improves image contrast and color reproduction. Type - aspherical.
The yellow filter in this model deserves special attention: the lens has a lighter shade of yellow than other IOLs. This is due to the concentration of the chromophore at the level of 0.02%. The light yellow shade has a number of pluses and minuses, one of the advantages is increased contrast, excellent vision at night.
The yellow filter of this lens does not transmit blue light rays of 400-480 nm, ophthalmologists consider this range to be optimal. Thus, the retina is protected from UV rays, the macula from phototoxic effects.
Approximate cost: 25,000 rubles.
AcrySof IQ Natural - Alcon (USA)
Very popular and widespread model. It is often referred to as an "intelligent lens". It has an aspherical shape and virtually eliminates the risk of aberrations (image distortion, color reproduction).
Material - hydrophobic acrylic. The elastic yellow model is designed specifically to protect the eyes from ultraviolet radiation, the harmful blue rays of the spectrum.
The aspheric effect is achieved due to the special shape of the rear surface of the IOL, which focuses the light rays at one point and transmits them to the retina so that the image is high-quality, clear, and contrasting. Moreover, the effect does not depend on the illumination and time of day.
The yellow color of the lens allows you to filter out the harmful parts of the spectrum ("blue" rays), protect the eye from ultraviolet radiation. The color filter protects the cornea, because during the operation the natural filter is removed along with the natural lens. At the same time, the saturation of the yellow pigment in this artificial lens meets medical standards, so that color perception will not suffer.
Approximate cost: 19,500 rubles.
Hoya ISert 251 – Hoya Surgical Optics, Japan
This IOL is made in Japan. It has all the advantages of classic aspherical lenses, while it stands out with a special design - monoblock two-component. The supporting elements (their tips) are made of polymethyl methacrylate by simultaneous polymerization, in simple terms: this lens will be accurately and securely fixed in the capsular bag, taking a clearly central position. Such accuracy will help to avoid sticking of the haptics to the optical part of the lens. This design also simplifies the process of implantation and "folding" and then "unfolding" the lens on the eyeball.
The lens is made of an innovative material - hydrophobic acrylic, which eliminates the effect of "sparkle". At the same time, the model has a yellow filter that protects against ultraviolet and harmful blue rays of the spectrum.
The aspherical balanced profile of the optical part perfectly corrects corneal spherical aberrations. With this lens, vision will be stable, without flashes and halos.
Approximate cost: 32,000 rubles.
Diffractiva-aAY "Human Optics" (Germany)
The elastic model of hydrophobic acrylic, according to the manufacturer, has an optimal balance between far and near focus. If the lighting is poor or the patient's pupil is dilated, then the focus is on the focus in the distance, but the near one does not suffer.
In the central optical zone, the diffractive element is limited, and the step heights are gradually reduced, thus it is possible to almost completely avoid optical disturbances.
The size of the optics is 6.0 mm, the haptic part is 12.5 mm. For near vision corresponds to an increase of 3.5 diopters.
Approximate cost: 60,000 rubles.
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