RU2542965C2 - Method for improvement of vision in phacoemulsification - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention refers to ophthalmology and can be applicable for treating cataract by performing an operation of phacoemulsification for the artificial intraocular lens implantation. A transparent and chemically neutral excipient that is PC-94 glycerol having a refraction index of more than one, or similar is introduced into the capsular sac through the same incision; that is followed by introducing cholesterol or lecithin eliminating the introduced excipient loss.

EFFECT: method enables reducing a risk of astigmatism.

2 dwg, 1 tbl

Description

The invention relates to the field of ophthalmology, and in particular to a method for treating the vision of people suffering from eye cataracts.

Cataract is one of the most common eye diseases among the elderly. The lens of the human eye is a “natural lens” that transmits and refracts light rays. The lens is located inside the eyeball between the iris and the vitreous. In youth, the human lens is transparent, elastic - it can change its shape, almost instantly “focusing”, due to which the eye sees equally well both close and far. With cataracts, the lens fibers are densified and deformed due to the formation of new peripheral fibers formed from constantly multiplying epithelial cells that have different growth rates. As a result of such a sluggish process, areas with different densities are formed in the lens body, which in turn form a kind of independent optical lenses. When light beams from an observed colored object hit the retina of the eye, several images of this object are displaced relative to each other. The retina forms impulses that enter the optic nerve through the channels of the nerve in certain areas of the occipital lobes of the human cerebral cortex, which, according to information from both eyes, creates a general idea of the visible object. Therefore, a person sees the subject as fuzzy, as if blurred, and the same thing happens with the color display, in which there are no borders for the transition of colors, and the overall color background takes on a grayish mushroom. Today, it is known that a change in the transparency of the lens during cataracts is associated with a violation of its structure and the ratio of the main components: water, proteins and trace elements, i.e. intraocular exchange. Over the years, the disease progresses: the body of the lens of the eye degrades, the area of turbidity increases and vision decreases. If treatment is not done in a timely manner, cataracts can lead to blindness.

Cataract treatment is only surgical, no drops or other drugs capable of eliminating the degradation of the lens and its clouding does not exist. The only treatment for cataracts today is phacoemulsification, which is an operation to remove the lens masses through a micro section from 2.0 to 2.75 mm and all further manipulations during the operation are carried out through it. The technique involves the use of a special device - a phacoemulsifier, whose action is based on the properties of ultrasound.

The steps for cataract surgery using ultrasound phacoemulsification or simply phacoemulsification are as follows:

1. Using a diamond tool, the ophthalmosurgeon creates a 2.5 mm incision. Viscoelastic is introduced into the anterior chamber of the eye using a cannula - a special substance that protects the internal structures of the eye during surgery from ultrasonic and mechanical stress and allows the ophthalmic surgeon to freely perform all necessary manipulations;

2. An ophthalmosurgeon introduces a special probe through a micro section, which, using ultrasound, makes it possible to turn a lens affected by a cataract into an emulsion;

3. Through a micro incision, a flexible intraocular lens (IOL) is inserted into the capsule, where the lens was previously placed, which is folded independently, which unfolds inside the eye and is firmly fixed. The IOL is inserted into the posterior chamber of the eye, into the lens capsule, behind the iris and is held by flexible loops or antennae. Now the intraocular lens will serve as the lens;

4. At the end of the operation, the entire mass of viscoelastic is washed out of the anterior chamber of the eye using an irrigation solution.

Modern ophthalmic surgery of small incisions allows cataract phacoemulsification without subsequent suturing, as the micro-incision is self-sealing. This makes it possible in the future not to limit physical and visual stress. The patient begins to see well immediately after the operation, and stable visual acuity is restored over a period of one week to two, three weeks. The intraocular lens (IOL) consists of the optical part and supporting elements that hold it in the eye. In its optical properties, the IOL is similar to a natural lens. It is reliable and can stand in the eye for life. There are many types of intraocular lenses. What type of lens is more suitable for the patient’s eye, the ophthalmosurgeon decides. The optical power of the artificial lens is selected individually for each patient and depends on the anatomical and optical characteristics of the eye. At first glance, phacoemulsification seems to be a panacea for cataracts. However, one should not forget that in most cases, cataract goes hand in hand with glaucoma, problems of the retina, cornea, etc. And the consequences associated with physical changes in the shape of the eye as a result of phacoemulsification are deeply understood.

Known, taken as a prototype, is a method of removing lens masses from the surface of the posterior capsule in case of complicated cataracts (patent 2414195 according to the application 2009143092/14, November 24, 2009 by Chenchik A.D.), in which after cataract phacoemulsification and aspiration into the capsule the lens is implanted with an IOL (intraocular lens) and the tip of the optical part of the IOL is pressed against the back of the capsule with the tip of the cannula and in this position they perform reciprocating movements on the surface of the capsule, clearing the lens masses that have settled on it. Then, after removal of the lens masses in the pupil zone, the IOLs rotate and the lens masses are removed from the areas inaccessible to visual observation by haptic elements, after which the cleaned lens masses are immediately aspirated. The method allows to expand the capsule of the lens, which provides a complete cleansing of the lens masses and prevents clouding and the occurrence of secondary cataracts.

The disadvantages of this method of treating cataracts are:

- The crystalline lens around the circumference has ligaments similar to filaments (the so-called cinnamon), which connect to the ciliary muscles located in the wall of the eye. These muscles can contract and relax. Depending on this, the cynical ligaments can also relax or stretch, as a result of which the radius of curvature of the lens changes - so a person can see clearly both close and far. This ability is called accommodation. During phacoemulsification, when the degraded lens is removed and replaced with an IOL, its connection with the ciliary muscles is broken. Therefore, an IOL having a constant optical power cannot work like a lens. This means that a person cannot see objects equally well both at long and close distances, i.e. after phacoemulsification, the effect of accommodation is absent.

- the lack of accommodation in the eye, due to the lack of communication of the ciliary muscles with the IOL, which has a fixed focal length, leads to the appearance of aberration, which manifests itself in the appearance of glare, ghosting around light sources, and a decrease in image contrast;

- after phacoemulsification, when the capsule bag is washed, its volume sharply decreases with the implantable IOL, the back wall of the capsule is shifted forward. The vitreous body of the eyeball also rushes forward, occupying the vacant space, and squeezes the back wall of the capsule. This leads to unpleasant physical sensations of the presence of a foreign object in the eye and, in turn, can lead to pinching of the pupil or injury to the cornea. Recall that the cornea, occupying approximately 1/6 of the outer shell of the eye, is a strong refractive surface, providing two-thirds of the optical power of the eye. In addition, with the displacement of the vitreous body, complications associated with deformation or partial detachment of the retina may occur.

After cataract phacoemulsification, postoperative astigmatism remains. Astigmatism is a visual impairment associated with a violation of the shape of the lens or cornea, as a result of which a person loses the ability to see clearly. With spherical optical lenses, the defect is not fully compensated. Astigmatism is combined with either myopia or farsightedness. This leads to the fact that after phacoemulsification the use of glasses is not canceled.

Thus, all the troubles accompanying cataracts, with the exception of acquired vision, will accompany the patient for the rest of his life.

And the most important thing in any operation, on something it was not performed, you should remember the golden rule in medicine "do no harm."

The present invention solves the problem of improving vision during phacoemulsification of cataracts due to additional surgical action, in which a transparent filler is introduced into the capsule bag through the same micro section, using the cannula in order to preserve the physical condition of the eye, which was before the operation.

The invention is illustrated by two figures. The figure 1 shows the human eye and the state of the main functional organs on which the phacoemulsification operation was performed, where 1 is an artificial lens (IOL), 2 is an capsule bag, 3 is a vitreous body and 4 is an optic nerve. The figure 2 shows the human eye after phacoemulsification using the proposed method, where 1 is an artificial lens (IOL), 2 is a capsular bag, 3 is a vitreous, 4 is an optic nerve and 5 is a filler. The main functionally optical element here is a capsule bag with an IOL and a filler.

A distinctive feature of the proposed method is that in the proposed method, phacoemulsification is performed with an additional action as a result of which a special filler is introduced into the capsule bag through the same micro section. A cannula is a modified “blunt” needle, devoid of its cutting sharp edge, and is used to introduce various drugs into the cavities and channels of the human body for diagnostic, therapeutic or research purposes.

A transparent, chemically neutral liquid, which has a density and a refractive index greater than unity, should be used as a filler. The closest physical and chemical parameters are possessed by glycerin of the PK-94 brand and the like, see table.

Table one Transparency transparent 2 Smell absent 3 Density 1.25 g / cm ³ four Refractive index 1,452-1,475 5 The purity of glycerol,% wt., Not less 98 6 Acid-base reaction, ml NaOH <0.2 7 Chlorides, Sulfate compounds (sulfates), carbohydrates are absent 8 Protein substances, Acrolein and others. Restore. substance are absent

Due to the lack of chlorides, protein compounds, carbohydrates and other reducing substances, the filler will not change its properties and transparency under the influence of sunlight.

The proposed method is performed in the following sequence. The patient prepared for the operation is transferred to the operating room, where he is placed on the operating table and the anesthetist performs intravenous anesthesia (rather than local anesthesia, as printed in the brochures on phacoemulsification). Then the ophthalmosurgeon performs an IOL implantation operation in the sequence of performing the above stages of the operation. Next, the operation continues, as in the proposed method, and the ophthalmosurgeon is introduced into the capsular bag with the IOL using the cannula through the same micro incision to fill the capsule bag. After this, cholesterol or lecithin is introduced into the capsular bag to avoid the loss of part of the filler using another cannula. At the end of the operation, the patient is taken out of anesthesia and moved to the rest room. The postoperative period can last two to three hours, after which the patient returns home.

The presence of a special filler is intended to replace the lens mass lost as a result of the operation and maintain the physical shape of the eye in order to avoid unforeseen complications after performing phacoemulsification.

The figure 1 shows the change in the volume of the capsular bag and the change in the shape of the vitreous body of the eyeball after performing standard phacoemulsification. The figure 2 illustrates the state of the shape of the eye after performing the operation of the proposed method, which shows that the physical shape of the eye has not changed.

Thanks to the proposed method, the operated eye takes on a natural, i.e. the initial form that he had before the operation. The elastic filler (5), replacing the liquid of the natural lens, allows the capsule bag (2) to maintain the original shape of the eye, eye pressure and, having its own refractive properties, allows creating an additional optical medium around the artificial lens (1), while replacing the absence of ciliary muscles, and provides additional support for the artificial lens. It also prevents the vitreous body (3) of the eyeball from changing its initial shape and pressing on the back wall of the capsular bag (2), which in turn eliminates trauma to the pupil, cornea and retina, and as a result, dramatically reduces the inconvenience of having an implantable IOL (1).

As a result of the application of the proposed phacoemulsification method, the structure of the optical apparatus of the eye, the magnitude of the eye pressure are maintained, additional support for the IOL is provided. Also unpleasant sensations of the presence of a foreign object in the eye due to the elimination of wrinkling of the capsular bag are eliminated. The optical properties of the artificial lens are supplemented by the optical property of the filler, which compensates for the lack of work of the ciliary muscles of the lens. In general, safety is ensured for the optical organs of vision of the eye, the best quality of vision by reducing the magnitude of astigmatism and aberration.

Claims (1)

A method of treating cataracts by performing a phacoemulsification operation to implant an artificial intraocular lens, characterized in that a transparent and chemically neutral filler is introduced into the capsular bag through the same incision — PK-94 glycerin having a refractive index greater than unity or the like, after which cholesterol or lecithin is introduced, excluding the loss of the introduced filler.

Images