RU2002456C1 - Artificial crystalline lens - Google Patents

Abstract

Using; The invention relates to medicine, in particular to ophthalmology. The inventive artificial lens of the eye contains an intraocular lens, the rear surface of which is made in the form of axially symmetric sections, the central section is concave in shape, convex at the periphery, and a flat section is located between them, the surface of which is parallel to the main plane of the lens. the area is determined by the formula O "O VN-K / K, where O is the diameter of the pupil of the eye under normal illumination of the object; N is the magnitude of the multifocal nature of the artificial lens; K is the sequence number of the location of the axially symmetric section from the periphery to the center of the lens 2i

Description

The invention relates to medicine, namely to ophthalmology, and can be used as an implantable artificial lens.

An artificial eye lens is known, consisting of an optical part and support elements, the optical part being made in the form of two sections connected by flanges having convex front optical surfaces and flat rear optical surfaces, while the focal lengths are due to the different radii of curvature of the front surface optical sections are different, which leads to the formation of a bifocal lens.

The disadvantage of this artificial lens is the complexity of the design, the inability to form a more than bifocal system, the difficulties in implantation associated with its installation and fixation in a normal position.

The presence of auxiliary rubber-plastic flange elements with a developed corrugated surface increases the likelihood of postoperative complications.

The closest in technical essence to the proposed one is an artificial lens of the eye, containing an intraocular lens, the rear surface of which is made in the form of axially symmetric sections, the section located in the center of the lens is concave in shape, and the peripheral part is convex .

The technical result of the invention is the creation of a three-focus artificial lens that provides high-quality vision of objects not only far and near, but also at a distance of 1-2 m.

In FIG. 1 shows the appearance of the multifocal lens from the side of its posterior surface; Fig. 2 is a lateral section of an intraocular lens (IOL) of a multifocal lens.

The artificial lens of the eye consists of an intraocular lens 1 and support elements 2.

The shape of the support elements and the method of attaching them to the IOL are known. The optical part of the IOL has a front refracting light path surface 3 with one radius of curvature and a back refracting surface 4, which contains two sections 5 and 7, made with different radii of curvature, the central portion being concave and convex at the periphery. and between them is a flat

surface 6 parallel to the main plane of the lens (see Fig. 2).

In an artificial lens, the lens is made of a homogeneous optically transparent material, for example polymethylmethacrylate, silicone polymer, glass, quartz, leucosapphire, cubic zirconia, diamond and other biologically inert crystals and amorphous compounds. The front and rear light-reflecting surfaces, if necessary, can be coated with a special antireflection film, which reduces the possibility of the formation of light-scattered glare in the IOL.

Depending on the material of the IOL, various methods can be used in its manufacture: casting, pressing, turning, grinding and polishing

0 optical surfaces. In the manufacture of high optical quality IOLs from solid crystalline materials, the most simple and preferred method is grinding and polishing.

5 surfaces on a sphere. A necessary condition for its applicability is the axial symmetry of the processed optical surfaces.

IOL sites located closer to.

0 to its center, provide a better (sharp) vision of more distant objects. The peripheral areas of the IOL provide a better vision of closely spaced objects.

5 One of the possible options for the 3-focal lens can be, for example, the IOL design with a central part providing high-quality vision of objects removed 5 meters or more,

0 the middle part, which provides high-quality vision of objects at a distance of 1-2 m, for working with a computer or some kind of operation board, and the external part, which provides sharp vision at

5 writing and reading literature, that is, to see objects at a distance of 25 - 30 cm.

Depending on the features of the aphidic eye, the implanted lens may have different optical powers, varying from +10 to +40 diopters. In this case, the difference in optical power between the periphery and the central part of the IOL should be 2.5 to 3 diopters.

5 In order to ensure the same brightness of images of distant and close objects on the retina of the eye, the diameters of axially symmetric portions of the posterior surface of the IOL with different radii of curvature are determined by the formula

Dn

where Do is the pupil diameter under normal illumination of the object;

N is the multifocal magnitude of the artificial lens;

K is the serial number of the axially symmetric portion of the posterior surface with an increase in the number from the periphery to the center. Example 1. Patient G., 22 years old. Diagnosis: congenital cataract of the left eye. Visual acuity: right eye-0.9; left eye - correct light projection.

Extracapsular cataract extraction was performed with implantation of a posterior trifocal artificial lens of the eye, taking into account the profession of locksmiths (it works at a distance of 60 cm - 1 m and 30 cm).

The diameter of the patient’s pupil under normal lighting is D0 3.2 mm, the multifocal size of the artificial lens N 3 selected during implantation (three foci). The value of the diameter of the axial symmetry form.

ARTIFICIAL EYE CRYSTAL containing an intraocular lens, the rear surface of which is made in the form of axially symmetric sections, the portion located in the center of the lens is concave and convex at the periphery, and the supporting part, characterized in that the rear surface of the lens has a flat a section located between axially symmetric sections parallel to the main plane of the lens, and its S 6

richio plot at K formula

1 calculated by

Di

-3.2

1.8 mm.

For (serial number of the axially symmetric section with an increase from the periphery to the center), the outer diameter of the middle ring is determined

Dz3, 2

 2.6 mm

An artificial lens was implanted taking into account the individuality of the patient with the optical power of the central part 18 D, the optical power of the middle ring 20 D, and the periphery-21 D.

The diameter of the central section is 1.8 mm, and the outer diameter of the middle ring is 2.6 mm.

Postoperative period - the eye is calm. Visual acuity of both eyes without correction 1,

(56) U.S. Patent No. 5002569, cl. A 61 F 2/16, 1991,

guides of internal diameters Dk

axially symmetric sections of the rear surface are determined by the formula

Ok 0 U M- | hell;

where Do is the diameter of the pupil of the eye when v

N is the multifocal magnitude of the artificial lens; K is the sequence number of the location of the axially symmetric portion of the back of the surface, determined from the periphery to the center of the lens,

7

561

B

FIG. 2