SU1736478A1 - Artificial lens - Google Patents

Abstract

This invention relates to ophthalmology. The purpose of the invention is to reduce postoperative complications. The artificial lens consists of an optical part and supporting elements provided with two diametrically opposite projections lying in the same plane with the optical axis of the lens, and in the gap between the legs the support part is made in the form of a dentate line, the ratio of the tooth height to the length of the dentate line lies in the interval from 0.028 to 0.041. 4 il.

Description

The invention relates to medicine, more specifically to ophthalmology, and can be used for the intraocular correction of aphakia.

The aim of the invention is to prevent postoperative complications.

The artificial lens of the eye consists of an optical part and a support element made in the form of two diametrically opposite projections located in the plane of the optical axis of the lens, the protrusions are interconnected by a connecting element with a serrated edge, and the ratio of the tooth height to the edge length lies in the interval 0.028-0.041 .

FIG. 1 schematically shows an artificial eye lens; in fig. 2-4 are diagrams explaining the calculation of the ratio of the height of the tooth to the length of the dentate line.

The artificial lens of the eye contains the optical part 1 and the supporting element 2. The determination of the ratio of the height of the tooth to the length of the dentate line is derived as follows.

To determine the length of the arc la on which the teeth 3 are located, it is necessary to initially determine the length of the arc I, which is clipped by the base ti of the protrusion 4 (Figs. 2 and 3).

The maximum width of the base of the protrusion 4 is no more than 3 mm (diameter of the pupil), the minimum width of the protrusion is 1 mm, since with a size less than 1 mm the protrusion becomes sharp and injures the tissues. The diameter of the optical zone is 6 mm (the diameter of the pupil in the dark).

The arc And 2 re R, where 2LI is full

360 °

the circumference and a is the angle supported by the arc I. The angle is calculated based on the width of the base of the protrusion ti (from 1 to 3 mm).

Angle a is calculated as follows:

. a ti / 2

44

with about

VJ 00

where R is the radius of the optical zone (3 mm). At c 1 mm,

sin | , from here tЈ 9 ° 5,. With tr

 3 mm, sin. hence 30 ° and 60 °.

From here, the length of the arc 1 at an angle of 19 ° is equal to 0.99 mm 1 mm, and at 60 ° - 3.14 mm.

The length of the arc for placement of teeth (2U is 2Lr-2I at ti 1 16.84 mm; at ti 3 mm; 12.56 mm.

When determining the number of teeth, the following optimality criterion should be used. To improve the fixation of the lens, it is necessary that the length of the dentate line tends to the maximum. This relationship is satisfied when t2 (the width of the base of the tooth) tends toward 0 (FIG. 4). According to clinical data, the width of the tooth must be at least 1.0 mm, since with a smaller value the tooth becomes acute and injures the tissue.

2 b Number of teeth Q. .

1 R Y4.

With q 1 mm, Q 16 (8 teeth on each side).

When ti 3 mm, Q -12j56 12 (6 teeth each

from each side).

The length of the dentate line L Q -2 ta, where xs - the length of the side of the tooth.

. a 0.5 1 When ti 1 mm, sin -rj - -A- t, hence

, 59 °,.

Length And at 19 °, And 2lN (2.3143 (19/360) 0.99 "1 mm, + 2and 2 H 18.84.

  for 19 ° 18.84-2h 16.84.

0 2 12 1M4 16 teeth

Q J2,56 12 teeth Length teeth

+ (l t2):

where h (tooth height 3 mm) side length of the tooth is t3 3.04 mm, with h (height 1 mm) side length of the tooth ta 1.12 mm, where h is the tooth height lying in the range of 1-3 mm (based on the magnitude and optical zone), a is the distance between the vertices of the diametrically opposite teeth lying in the range of 8–12 mm.

It can not be less than 8 mm, since it threatens to dislocate the lens into the anterior chamber with a maximum expansion of the pupil and can not be more than 12 mm, as it will cause trauma to the tissues of the iridociliary groove.

13 at h 1 mm 1.12 mm, at h 3 mm 3.04 mm.

So the length of the jagged line and

the ratio of t is equal to:

1) at Q 16; h 1 mm;

L 35.2 mm and Ј 0.028;

2) at Q 16; h 3 mm;

L 96.96 mm and Ј 0.0309, 3) at Q 12; h 1 mm;

L 26.9 mm and -g-:

0.0372;

4) at Q 12; h 3 mm; L 72.96 mm and Ј 0.0411.

With a ratio of -r- 0.028 is violated

the stability of the lens, as the jagged line is practically transformed into an arcuate.

With respect to t - 0.041 teeth become

long and sharp and can damage eye tissue.

The implantation of the proposed artificial lens is carried out as follows.

After intracapsular cataract extraction in any conventional manner, the proposed artificial lens is introduced into the posterior chamber of the eye through the pupil, planting one of the projections 4 for the lower part of the iris. Then, using a rough spatula, lightly press on the lens and at the same time move it with light oscillating movements left and right, lateral IOL sections with a serrated edge fill the iris.

Finally, using the same spatula, slightly pressing the lens against the vitreous body and moving it downward, fill the second protrusion of the support element 2 over the upper sections of the outer sheath, thus completely positioning the lens on the anterior vitreous boundary membrane.

Due to the combination of distinctive features indicated in the claims, the artificial lens is easily and freely implanted into the posterior chamber on the anterior marginal membrane of the vitreous body and it occupies a stable central position relative to the optical axis of the eye. For implantation not

special technical devices are required. During implantation, the artificial lens freely slides relative to the surrounding tissues of the eye without injury.

Example 1, Patient S., 47 years old, a librarian, was admitted with a diagnosis: the cataract was complicated. Acuity of vision is the correct projection of light. Intracapsular extraction of the cataract was performed with implantation of an artificial lens with a ratio of tooth height to the length of the dentate line 0.028. The operation was performed on an outpatient basis and on the day of surgery the patient was sent home. The next day, with biomicroscopy, the lens held a stable right position centrally relative to the optical axis of the eye. The acuity of the vision was 1.0 and persisted throughout the entire observation period of 1.5 years. After 1 month the patient began work by profession.

Example 2. Patient 3., 76 years old, retired. He was admitted with a diagnosis: mature cataract, subluxation of the lens, operated with primary glaucoma. The lens is removed in the capsule without loss of the vitreous body. The pupil is rigid, poorly dilated, and implantation of a lens with the prototype would be impossible. An artificial lens of the eye is implanted with a ratio of a tooth height to the length of the dentate line 0.041,

In the postoperative period, the intraocular lens was stably in the correct position, despite the fact that the patient used the crutches because of a leg disease and was sharply tilted and straightened when walking from the first day after the operation. The patient was discharged on the second day after surgery with an acute vision of 0.5.

The implantation of the artificial eye crunch / eye according to the invention is shown.

after intracapsular extraction of complicated, congenital, age-related and traumatic cataracts.

The use of the proposed artificial lens of the eye allows reducing operative and postoperative complications by 15% when it is implanted into the anterior marginal membrane of the vitreous — such as anterior rupture

boundary membrane of the vitreous body and its loss as a result of this, decentration and dislocation of the lens, falling number of cells of the posterior corneal epithelium. Design advantages

the proposed artificial lens is allowed to implant in the absence of the posterior capsule of the natural lens, i.e., without a strong support and without support on the iris, which preserves the structure and functions of the latter; as injuries to the cornea, anterior vitreous boundary membrane, dislocation and decentralization of the IOL and, consequently, reduced visual acuity are excluded

after operation. The implantation of an artificial lens is carried out by constructively simple, widely available instruments with a light slip of the lens over the anterior border membrane.

Claims (1)

vitreous body for the iris without injury, without contact with the easily damaged cells of the posterior corneal epithelium. Claims of the invention An artificial lens of the eye, consisting of the optical and supporting parts, characterized in that, in order to prevent postoperative complications, the supporting part is made in the form of two diametrically opposite projections, located in the plane of the lens, and the protrusions are interconnected by a connecting element with a toothed edge, and the ratio of the height of the tooth to the length of the edge lies in the interval 0,028-0,041. W V .3