Cataract: it's waiting for you personally

If you live, of course

Ophthalmology Clinic of Dr. Shilova, Geektimes

This is the model of an intraocular multifocal lens from Carl Zeiss.
The real size of such a lens is 11 mm, the diameter of the optical zone is 6 mm.

Cataract is, simplifying, age–related clouding and compaction of the lens. According to the classical definition, we are talking about opacities of any type. First, something gets in the way in the field of vision, a general "fog" appears, you want to wipe dirty glasses, then you don't see the letters in the book, then you want to turn on the light brighter or, conversely, hide from the bright light, and then wake up one fine morning and realize that you can't find slippers. And you don't see anything at all– just shadows. This process sometimes stretches for many years, but the slippers will still be lost. Mentions of opacity developing in the eyeball are found thousands of years before our era. 

The treatment procedure has historically been very peculiar – reclination of a cloudy lens. The doctor saw a patient with a very dense lens – to the point that the patient is already blind. During the excavations of the settlements of Ancient Greece and Rome, tools were found that doctors used to remove cataracts – sharp needles that pierced the eye and lens, destroying its supporting apparatus. The lens could come off and, due to its gravity, also fall down from a blow to the back of the head with a heavy stick several times. Sometimes the patient died in the process of emergency ophthalmological care, sometimes he received a concussion, and sometimes the lens broke off from the ligaments and flew deep into the eye. The patient began to see again – he had a huge bump and vision of about +10 +15 diopters. 

Now two pieces of news. The bad news is that people are increasingly living up to cataracts, and it is inevitable. The good news is we have something better than sharp needles and a heavy stick. 

What happens to the lens with age

The cornea (cornea) is the first most powerful refractive lens of the eye, it is formed around the age of 16-18 and changes slightly during life. Then we have the second "group of lenses" – lenses (lens is a natural lens in English terminology). And already behind him, through the vitreous body – the sensor, that is, the retina (retina). 

The lens is responsible for refraction of light (about +20 diopters at rest and about +30 diopters at tension) and focusing of the eye. When we look at a book, the muscles tense up and form it so that the focus falls on the letters. When we look at an airplane in the sky, the muscles relax, and the lens forms almost parallel rays. The muscles are not located in the lens itself, but in the area of the so-called ciliary body, the ligaments of the lens are attached to them, which, in turn, allows you to achieve accommodation, that is, this fine-tuning to the desired focal length by changing the shape of the lens. If you get the lens at all, you will see with glasses somewhere at the level of +10 to +15 diopters. 

With age, the lens gradually becomes dense and becomes cloudy. A young person usually has only 60-65% of the water in the tissues in the lens. In old age, the amount of fluid decreases. Although the lens "floats" in the liquid, it is relatively dry. On the other hand, there are no tumor or inflammatory processes in the lens itself due to its structure and the absence of vessels. The lens does not hurt, because there are no nerve endings in it.

Often, cataracts, as they develop, cause a weakening of presbyopia and the appearance of the ability to read without glasses, that is, two age-related pathologies suddenly correct each other. But this is an imaginary improvement in vision, while the image quality is poor – this is an iconic symptom of the development of cataracts. 

At about 60-70 years of age, the lens completely loses its ability to accommodate, that is, it becomes rigid, large and inelastic. The lens also turns yellow with age. 

Yes, I must say that cataracts are not necessarily an age–related phenomenon. There are congenital cataracts (if a woman suffers from some infectious, systemic or genetic diseases during pregnancy). 

There are complicated types of cataracts that appear with concomitant diseases of the eyes or the body as a whole, for example, diabetes, arthritis, etc. Taking some medications also causes the appearance of cataracts. 

And, of course, any injury to the eye can cause the appearance of cataracts, even if there was no direct contact with the lens. It is now known that cataracts are caused by strong infrared radiation, as well as various radiation factors, and not immediately, but years later. This, in particular, calls into question the use of powerful lidars of unmanned vehicles operating in the IR spectrum - so far their effect on the eyes has not been studied in the future for several years. It is also known that the ultra-high frequency current also leads to the development of cataracts. Cataract can also be caused by poisoning, in particular (very characteristic) with nitrocolor. In animals, cataracts have learned to be predictably obtained with naphthalene and specific diets. 

But let's return to the usual age-related cataract. A very characteristic symptom of the process that has begun is that the patient feels that he has "dirty" glasses, and there is a constant desire to wipe them. If you suddenly notice this for an elderly relative, then it's definitely time to change the lens. 

Sometimes patients misinterpret the symptoms that have appeared. Very often, a cataract matures by compacting the lens – along the sclerotic pathway. In this case, a cataract patient who was reading with glasses suddenly begins to notice with surprise that it is now hard to see in them and there is an opportunity, even in a "fog", but to read the text without glasses. The patient feels joy and thinks that he has become better at seeing. Alas, this is a bad symptom! He says that it is necessary to plan a visit to an ophthalmologist.

Often cataracts lead to the fact that myopia, which has been stable for years, suddenly begins to intensify. Sometimes up to huge values – -20 diopters or more. In general, frequent change of glasses is an early sign of the appearance of cataracts.

The second variant of cataract maturation is no better – hydropic, when the lens begins to increase in volume, becomes hydrated, swells and leads to increased intraocular pressure and rapid loss of vision.

There are also a number of symptoms: at dusk it becomes better to see than during the day, rainbows and double vision bother, astigmatism appears or increases. In general, cataracts are very diverse in their manifestations, it is impossible to make a diagnosis on your own, for this you need a visit to an ophthalmologist.

When is the lens removed?

There are three types of indications for lens replacement: optical, refractive and medical. 

Optical indications are when the aging and compaction of the "bulb" in layers has reached its logical end and the lens darkens. When a cataract begins to reduce vision qualitatively or quantitatively. It feels like a smoked glass has been inserted into the eye or as if you are looking at the world through glass splattered with semolina porridge. Even the initial cataract, which is the cause of vision loss, requires removal. 

The old term "immature" is not a reason to wait for maturation. The diagnosis of "cataract" is a reason to replace the lens. 

When a person no longer sees objects and only light perception remains, this is the last stage of mature cataract. It is better not to bring it to it, in particular because a change in the lens causes numerous disturbances in the normal operation of the eye. In mature and overripe forms, the lens capsule, ligamentous apparatus suffers, removal requires a large amount of ultrasonic energy, which, in turn, destroys the cornea, its delicate endothelial layer. In general, if you are delaying the replacement of the lens, then you should be prepared for the fact that the operation will be longer and traumatic, with a long recovery period.

Refractive indications – changes in the optics of the eye. By replacing the lens and correct calculations of the optical strength of the implanted artificial one, we can change the refraction of the eye to the desired value – to save the patient from a large "minus" or "plus", correct astigmatism, get rid of age-related hyperopia. In this case, the cataract does not develop, and the optics of the eye remains stable forever.

More often this method is used for patients older than 40-45 years, when the first symptoms of presbyopia appear. 

Medical indications are when one's own lens is the cause of concomitant changes in the eye, for example, when there is a subluxation after injury and there is a risk of dislocation, when it is a reason for the formation of glaucoma (dangerous increase in intraocular pressure and death of the optic nerve), etc. That is, again, simplifying, the lens will change sooner or later anyway, but because of the risk of pathologies, sometimes it needs to be changed a little earlier than it will develop a resource. 

Is it necessary to wait until the patient is completely blind?

Patients often use this logic: while the eye sees something, it is not necessary to operate the lens. In fact, today, on the contrary, the lens is operated on as early as possible, when it is already clear that the irreversible process has begun. The reason – in addition to protecting against the risks caused by changes in the metabolism in the eye, is that the softer the lens is at the time of surgery, the less invasive the method will be applied, and the lower the risk of complications. 

The generalized global risk of severe and serious complications of lensectomy ranges about 6%. In the case of late stages, it can reach 20-30%. In the early stages, it is 1-2%. In the case of using modern access equipment, very accurate selection of the implant lens itself and more than 5 years of surgical experience - less than 1%.

Another important point is that you yourself will never be able to independently determine what state your lens is in. There are a number of factors that make surgeons recommend surgery at an earlier date: weak ligamentous apparatus of the lens, short or, conversely, long eyes, eyes with a small anterior chamber, the condition of the corneal endothelium and other things that only a specialist who performs operations of this type can evaluate. Quite often, polyclinic doctors act as an adviser, who are not always well versed in the technique of surgery and in the indications for lens replacement. Calming the patient with the words "you have an immature cataract, it's too early to operate", they do the patient a "disservice" – inaction leads to when the optimal timing is missed. 

In general, cataract surgery in ophthalmology is like appendicitis surgery in general surgery. It is considered the most basic and the most predictable in the standard case, the most creative in the non–standard case. If everything goes according to the script, even an inexperienced surgeon will get a good result. If something goes wrong (and this cannot always be predicted in advance), then only an experienced surgeon will be able to find a way out of an unusual situation. I have to do reconstructive surgeries very often, almost weekly, after unsuccessfully performed surgeries in other clinics. Sometimes the volume of such surgery is huge – operations lasting not 10-15 minutes (as with a standard cataract), but 1-2 hours of "creativity". 

An important point in cataract surgery is the choice of the lens. And the main factor is taking into account the individual characteristics of a particular patient. Models of IOL (intraocular lenses) differ in the material of manufacture, the shape and number of supporting elements, the structure of optics (spherical, aspherical, astigmatic), the method of attachment. Therefore, it is better to choose not an American or German one, "like a neighbor", but the one that your surgeon considers the most suitable for your eye.

And the most important thing. Replacing the lens restores the transparency of optical media and can improve the optics of the eye, but it will not create a new eye. If there are concomitant problems with the retina, optic nerve, cornea or brain, i.e. other problems to reduce vision, then they will ultimately determine how you will see after surgery. That is, the postoperative visual acuity will be the same as your visual analyzer as a whole. 

Where is it better to do the operation?

The following is important: the "planned" replacement of the lens is included in the CHI package. The patient always has the right to choose whether to apply to the nearest territorial polyclinic for a referral to a budget institution or to come to a paid clinic for diagnosis and surgery. To the question "where is better?" there is no single answer. Everyone chooses based on their life experience, advice from friends, financial situation, mobility and much more.

There is one piece of advice when choosing a CHI option: if you were offered to buy a lens or all the "consumables", motivating by the fact that the hospital does not have lenses or something else, then you know - you are being deceived. The CHI system does not involve co-financing, that is, if you receive a service under the CHI policy, then everything should be free for the patient, including a lens, solutions, etc., or everything is paid. Two options. Partially – impossible. The amount that is transferred to the hospital for this service includes payment for everything that is needed for this technology. And if you bought from a certain company (as a rule, on the advice of your doctor in a particular company "Horns and Hooves"), then where did it go and who will get the lens that will be written off for your operation? This practice is rare in the regions, and very frequent in large cities. 

For the rest, you need to know that cataract operations do not require hospitalization and are performed on an outpatient basis. When using modern high-tech techniques, they last only 10-15 minutes, are completely painless, have no age restrictions. After the operation, the patient almost immediately leads a normal lifestyle, for a month burying drops in a familiar home environment. 

Will the implant accommodate?

The term "accommodation" is applicable only to the natural lens. But if we expand the question to "will the artificial monofocal lens focus at different distances without additional correction with glasses", then the answer is no. It is adjusted to a certain focal length, the choice of which is always discussed with the patient. If a person has always seen into the distance without glasses, and he needed reading glasses only after 45-50 years, then, as a rule, the calculation of the lens is done for distant vision and for nearness in this case, additional correction with glasses with plus glasses will be required. If the patient was nearsighted and read without glasses, then you can stop at the residual myopia of -2 -2.5 diopters and glasses for distance.

For greater independence from glasses, in some cases, the principle of "monovision" is used, when the optics in the leading eye are calculated for long-range focus, and in the ignorant eye a calculation is made for nearness. This choice is always discussed with the patient and tested in advance.

There is a concept of the so-called "accommodation of the pseudofakic eye", that is, eyes with an artificial lens. This process involves not only the ligamentous apparatus, but also the vitreous body and the entire posterior pole of the eye, as well as the cornea. This process is hardly predictable, and during the first year after the operation it significantly weakens.

There is another type of lenses that have multifocal optics that can create focusing at different distances without additional correction with glasses. 

These are lenses that refract light with several foci, allowing you to see objects at different distances. Thanks to these lenses, patients get the maximum dependence on glasses in their daily life.

Along with age-related hyperopia, artificial multifocal lenses allow correcting myopia, hyperopia, as well as astigmatism.

The trifocal lens is an advanced multifocal lens with an additional focus. It allows you to clearly see objects both near and far, and at an average distance. And the patient can work on the computer without any problems.

Since after implantation of an artificial lens, the refractive range of the eye will no longer change, so the patient can get rid of glasses for life. The great advantage of living without glasses is associated with a slight decrease in the quality of vision in some areas. This is due to the physical principle underlying the design of multifocal and trifocal lenses, which constantly divide light into near, far and intermediate. 

However, due to the high degree of light transmission of trifocal lenses, undesirable light scattering or light effects practically do not occur. Even in poor light conditions, very good refractive results can be achieved.

After implantation of such lenses, adult family members often see better than their children, grandmothers – better than grandchildren. Very often after that they begin to complain that before the operation their own face and the faces of relatives were "younger", complain that they have aged, and rejoice in the long-forgotten colors of the world. Choosing a lens is always an individual task that you can solve only together with your surgeon. Because the replacement of the lens is done once and for all, you do not need to change the lens during your life.

Portal "Eternal youth" http://vechnayamolodost.ru  21.04.2017