Artificial intraocular lens: species, producers, reviews

The lens plays the role of the lens in the eye. He is able to focus light in the retina. Before the advent of the artificial lens patients after the removal of cataracts wore glasses with very massive plus glasses or contact lenses.

For today, the choice of artificial lenses is very wide. Not even any surgeon understands the variety of models. The main types of the lens will be described in this review article.

In what cases is an implantation of an artificial lens required?

The intraocular lens is implanted in the natural lens area, provided that it has lost its natural functions. For example, during an operation to remove cataracts, when the natural lens loses its transparency, the IOL makes it possible to correct myopia, hyperopia, and astigmatism of a high degree.

The lens placed inside the eye can act as a natural lens and provide all the necessary vision functions.

The invention of the phakic intraocular lens has become a true solution to the problem for patients with a high degree of myopia, hyperopia and astigmatism. Also, such models are established for patients who, due to various reasons, are not allowed to perform vision correction with a laser.

An alternative to laser vision correction is the method of refractive lens replacement with an artificial IOL model. The visual apparatus at the same time loses the ability of accommodation (the vision of objects located at different distances). After such an operation, the patient is required to wear glasses for reading and seeing objects near. This method is indicated in the event that natural accommodation is lost, which usually applies to patients older than 45-50 years of age

Implantation of the phakic intraocular lens has proved itself from the very best side if natural accommodation has not yet been lost and there is the possibility of implantation of the lens without removing the natural lens. Phakic lenses enable the patient to see objects both near and at a distance.

IOL device

Usually the intraocular lens includes two elements: the optical and the supporting.

The optical component is a lens made of a transparent material. It is combined with the living tissues of the eye. On the surface of the optical part there is a diffraction zone, which makes it possible to obtain a clear vision. The supporting part is responsible for the reliable fixation of the lens in the capsule of the eye.

Implanted artificial intraocular lens does not have a shelf life. It provides a person with full vision for many years.

Main advantages of phakic models

• Do not touch the iris and cornea, which prevents the development of dystrophic changes.
• Biologically combined with the eye of a person.
• They have special protection for the retina from the negative effects of ultraviolet radiation.
• Provide early recovery of vision.
• Preserve the structure of the cornea.

Hard and soft modifications

Lenses are divided into two main types: hard and soft. In the practice of ophthalmologists around the world, the golden rule was the operation without seams - phacoemulsification.

The phacoemulsification of cataracts by implantation of the intraocular lens suggests a 2.5 mm long incision. The lens must be soft. This allows you to roll it into the tube through a specially designed injector for these purposes. Inside the eye, he straightens and performs the role of the lens.

The outdated technique assumed the execution of a 12 mm long incision and suturing for six months. So the rigid model was implanted.

Spherical and aspheric type of IOL

Aspheric intraocular lens provides minimal glare from light sources day and night. This means that no matter where it hits the light, it will everywhere be subjected to refraction, both in the center and along its edges. This is a very important indicator for the dark time of the day, when the pupil of the eye is maximally expanded.

For example, there is no glare from the headlights of cars. This property is very important for drivers. Also, the aspherical type of the lens has an optimal color transfer and a high contrast level.

The spherical type involves refraction of different intensities in different regions of the lens. This contributes to the dispersion of light, which adversely affects the quality of the visual function. This type of lens can trigger the appearance of highlights and highlights.

Multifocal and monofocal model

Monofocal lens is designed to provide high-quality visual perception of objects located in the distance. For reading after surgery, you need plus points.

The device of intraocular lens (IOL) of multifocal type is the most advanced. This determines its high cost. It allows the patient to see objects at all distances. This function is provided by a complex configuration of its optics. For vision near, in the middle and in the distance three different zones answer. The patient does not need to wear glasses. That's why the cost of such devices is extremely high.

Toric models

Toric models are designed to solve the problem of astigmatism. Astigmatism is the wrong shape of the cornea, which distorts the image. If such a patient is to remove the cataract and put the lens of the standard modification, the pathology will not disappear. Hence, after the operation, he will again be shown wearing cylindrical glasses.

When the toric lens model is implanted, the patient can be compensated for astigmatism and obtain a contrast vision of objects. The required cylinders are already built in the toric lens. Having installed such a lens into the eye by means of special marks on the lens, the patient can achieve a clear image.

Installation of such models requires clear calculations before surgery. For each patient, they are held individually.

Reviews of patients suffering from astigmatism indicate that implantation of toric models brings the best result. Many patients after the operation note that their vision has become so clear that it was not even in their young years.

Multifocal toric lens

A series of IOLs is completed by a multifocal toric model. If the patient suffers from astigmatism and wants to see equally well both near and at a distance, then this implantation is indicated to him. This lens allows you to restore your eyesight. The patient's glasses will never be needed. This is the most expensive form of the lens.

Ultraviolet IOL filters in yellow and blue

The natural ocular lens has a unique protective ability that blocks harmful radiation from the sun. This prevents damage to the retina. Modern ophthalmology involves the release of all types of IOLs with a filter from ultraviolet.

Special models of lenses are colored with yellow pigments in order to achieve the maximum resemblance to the natural lens. These filters screen out harmful blue light that is in the invisible part of the spectrum.

AcrySof IQ

Intelligent lens AcrySof IQ serves to correct spherical aberrations (the presence of glare, halos, light) in bright light. This model is able to give beautiful eyesight under any conditions of illumination. This is an ultrathin lens (twice as thin as usual).

In the central part, the usual lens is thinner than on the sides. It is because of this that the light rays that pass through its peripheral region are focused to the retina, and the central rays are on it. So the rays of light do not focus at one point. As a result, the image on the retina is not clear.

Intraocular lens AcrySof IQ eliminates this problem. Its back surface is designed in such a way that it makes it possible for all light beams to gather at a single point. The image provided by this model is distinguished by a high level of quality, contrast and clarity at any time of the day.

Replacement of the lens with cataracts in an operative way

To date, implantation of the intraocular lens by ultrasonic phacoemulsification is a manipulation with a small fraction of the risk for patients. It has a high level of efficiency. Almost 95% of cataracts in Europe, the US and our country are removed in this way.

The World Health Organization recognized the operation as the only one among all surgical interventions, which is characterized by complete rehabilitation.

What is the essence of surgical intervention?

The basis of the operation to remove cataracts is the removal of the clouded lens, which prevents the full flow of light to the retina. An artificial intraocular lens replaces a damaged natural lens.

The main stages of implantation

The vast majority of phacoemulsification is performed in private clinics on an outpatient basis. The stages of preparation for the operation are almost the same everywhere:

• An hour before the operation begins, the patient must report to the clinic.
• To enlarge the pupil, he injects drops containing anesthetic.
• The patient is placed on the operating table. Anesthesiologist makes anesthesia.
• The surgeon removes the cataract and implants the lens.
• The operation does not require suturing.
• After the operation, the patient is redirected to the ward.
• An hour after the operation, the patient is sent home.
• The next day the patient should come to the doctor for an examination.

How is surgery performed?

To obtain access to the cornea, a microscopic incision of 1.8 mm is made. The turbid lens is softened by ultrasound and transformed into an emulsion that is removed from the eye. Intraocular flexible lens is inserted into the capsule by means of an injector. It falls into the eye in the form of a tube, where it itself is turned and securely fixed.

The microscopic incision is subsequently sealed without external interference. Therefore, suturing is not necessary in this case. Vision to the patient returns, as a rule, already in the operating room.

The duration of the operation is 10-15 minutes. In this case, drip anesthesia, which is easily tolerated by the body and does not affect the heart and blood vessels. After surgery, the patient quickly joins the normal rhythm of life. Restrictions are minimal. Basically they concern hygiene.

Rehabilitation period

After the end of the operation, the doctor prescribes the patient special drops for the eyes and determines the frequency of their use. Also, dates for additional examinations with a preventive purpose are appointed. The patient is allowed to lead a habitual way of life for him: reading, writing, working at a computer, watching television programs, taking baths, sitting and lying in a comfortable position. Restrictions on the diet also does not exist.

What is the complexity of the operation?

Implantation of the intraocular lens has a certain complexity, which lies in high requirements for the accuracy of calculation and selection of the lens model, as well as the professional work of the ophthalmologist. That is why the most important condition before the operation is a complete diagnosis. Only a detailed examination, conducted through a whole complex of modern equipment, makes it possible to obtain an objective state of view of the patient.

Benefits

Ultrasonic phacoemulsification of cataracts is distinguished by the perfection of technology worked out over many years. The operation is conducted in a short time. The patient feels comfortable and safe. However, behind such a notion of manipulation is the high skill of the operator and the utmost clarity of the organization of the process.

The main advantages of such a surgical intervention include:

• Absolute relief from cataracts;
• Achievement of high visual characteristics;
• Rapid recovery of the patient;
• Absence of restrictions for physical and visual loads due to the seamless method;
• No pain, since the lens does not have nerve endings;
• The passage of rapid rehabilitation, a week later you can go to work;
• Compliance with restrictions for a month;
• Perfect transmission of lenses in color and contrast.

Indications for operation

Indications for surgical intervention can be cataract at any stage. The optimal option is to perform surgical intervention with an immature form of cataract, which allows to carry out the operation without risk.

For the patient this is also a big plus: do not wait for the moment of complete blindness of the eye, as it was before. Removal of turbidity at the initial stages of the development of the disease minimizes complications both during and after surgery.

Possible complications after surgery

In the vast majority of phacoemulsification, the implantation of the intraocular lens, which is carried out by professional surgeons, has a favorable outcome. If the surgeon is a beginner, then in 10-15% of cases complications are noted.

They can be caused by:

• Weakness of ligaments of the lens;
• Combination of cataract with diabetes mellitus, glaucoma or myopia;
• Presence of common eye diseases.

Complications after surgery include:

• Corneal damage by ultrasound;
• Violation of the integrity of the ligaments of the lens;
• Rupture of the capsule of the lens, causing the loss of vitreous body;
• Displacement of the artificial lens, etc.

It should be noted that all complications that have arisen after surgical intervention can lead to serious problems. Treatment in this case will be of a lengthy nature, and the result may not be very positive.

Removing the lens

Sometimes, with the inflammatory process or pathological processes in the retina, removal of the intraocular lens is required. In such cases, a total vitrectomy of the IOL is performed. The lens is gripped by tweezers and moves forward. The sclerostoma for the endo-illuminator is closed with a cap. The surgeon performs an incision in the cornea by means of scissors with diamond spraying. The IOL can be intercepted by a doctor from 25G tweezers to another, for example, 20G diamond-plated tweezers.

After removing the lens, the incision is sewn with a solid or X-shaped seam from the nylon No. 10-0. Using a thin material for the seam causes a lesser manifestation of astigmatism, but requires extreme caution, since the risk of leakage through the seam during manipulation is high.

Sometimes the intraocular lens is removed in the presence of a fibrovascular membrane, which is the result of fibrovascular proliferation on the anterior base of the vitreous humor due to trauma or uveitis. Such a process can be caused by diabetes mellitus.

In this case, the haptics are intersected by scissors, and in order to maintain the depth of the anterior chamber, apply viscoelastic.

Haptic elements can be left in the eye cavity if they are surrounded by a fibrous capsule and can not be removed by tweezers. To increase the level of tightness on the wounds, several X-shaped seams are applied. A mono-flemic string No. 9-0 or 10-0 is used.

Which IOL manufacturers are preferred?

How to choose intraocular lenses? Manufacturers represent a wide range of models with different characteristics. To date, widely used modifications of phakic lenses ICL (STAAR, CIBA Vision) with a back camera.

These models are subject to implantation behind the iris in front of the lens and provide high optical characteristics. If desired, such lenses can be removed from the eye without disturbing its anatomy.

Reviews

Intraocular lenses, reviews of which are the most positive, have become for many people the only and correct way to restore lost vision.

According to the patients' feedback, ultrasonic phacoemulsification of cataract with IOL implantation is a highly effective, reliable and painless method that can cataract forever and provide excellent vision. The intraocular lens has become a real breakthrough in the field of cataract treatment.