RU2772050C1 - Intracapsular segment - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to medicine, namely to devices used in ophthalmic surgery. The device for implantation into the lens capsule is made in the form of an intracapsular segment, which is a segment of a ring with a length from 90° to 180°, made of plastic, having rings with holes at the ends, and in the middle part an element for fixing to the iris of the eye, which includes two identical loops fixed on a segment of one of its sides, the vertices of which are directed to the center of the ring. At the same time, in the lower part, without reaching the arc of the ring segment, the loops are connected by an I-shaped junction, in the middle of which a slot is made with the possibility of pinching the iris tissue in it, similar to the slot in the haptic elements of the intraocular lens, designed to pin the peripheral part of the iris stroma in it. At the same time, a smooth bend is made at the top of the loops of the fixing element with the formation of a distance between the plane of the ring segment and the plane of the loops of the fixing element, varying depending on the structure of the anterior segment of the patient's eye from 0.3 to 1.0 mm. Moreover, the length of these loops from the arc of the segment to the top of the loops is selected based on the possibility of removing the loop from the capsule bag under the iris, taking into account the size of the capsule bag and the size of the patient's capsulorexis, and the length of the loops from the slot between them to the top is selected based on the condition of ensuring the possibility of fixing the slots of the fixing mechanism to the peripheral part of the iris stroma.

EFFECT: application of this invention will make it possible to achieve the prevention of dislocation of the intraocular lens in the capsule bag both during surgery and in the postoperative period due to the reliable fixation of the arches of the capsule bag to the stroma of the peripheral zone of the iris.

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Description

SUBSTANCE: invention relates to medicine, namely to devices used in ophthalmic surgery, and can be used for implantation into the lens capsule in case of severe weakness or defects of the lens ligamentous apparatus of various degrees to ensure the stability of the position of the intraocular lens (IOL).

Known intracapsular devices to ensure a stable position of the IOL, for example, intracapsular spacer ring manufacturer "Medin-Ural", Russia, (http://s96551qs.bget.ra/mikrokhirurgiya/vspomogatelnye-instrumenty/bkc.html). The intracapsular spacer ring does not have additional fixation mechanisms and is used in case of weakness of the ligamentous apparatus of the lens, as well as in the presence of its defects, but not more than 1 quadrant (4 hours of the conventional dial). The main disadvantage of the intracapsular spacer ring is the lack of additional fixation mechanisms and, accordingly, limited indications for its use.

Also known is the modified intracapsular Cionni ring (https://fci-ophthalmics.com/products/cionni-ctr), as well as the Ahmed intracapsular segment (https://www.beye.com/product/ahmed-capsular-tension-segment) . The modified Cionni ring, as well as the Ahmed intracapsular segment, have additional mechanisms for fixing to the sclera. So, if the lesion of the ligamentous apparatus of the lens is ≤1 quadrant, the Ahmed intracapsular segment is used, and if the lesion is >1 quadrant, the modified Cionni ring is used. The main disadvantages of the Ahmed intracapsular segment and the modified Cionni ring are the high trauma and invasiveness of the procedure, the need for additional sutures during transcleral additional fixation of the IOL, the risk of potential complications such as vitreous hemorrhage, and insufficient reliability due to the fact that suture fixation may weaken over time.

Also, with weakness and defects in the ligamentous apparatus of the lens, intraocular lenses with an iris-claw mechanism (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3638330) can be used. The fixing elements of the iris-clow IOL have slots in which the tissue of the iris is pinched, thus fixing the IOL to it. The disadvantage is the need for a large incision, as well as the risk of astigmatism after surgery.

A device is known for fixing the edge of the anterior continuous circular capsulorhexis to the pupillary edge of the iris, made of biocompatible elastic threads in the form of outer and inner ovals, located one inside the other, in the same plane, and connected at one point, lying on both major axes, while large the axes of both ovals lie on the same straight line, and the ratio of the length of the major axis of the outer oval to the length of the major axis of the inner oval is from 1.1 to 1.5 (patent RU 2293545, IPC A61F 9/00, publ.: 20.02.2007) .

The disadvantages of fixing the capsular bag to the pupillary edge of the iris include the restriction of pupil excursion, which prevents its expansion both in natural conditions of reduced illumination, and, if necessary, to perform drug mydriasis for therapeutic or diagnostic purposes. In addition, constant traumatization of the iris tissue in the pupillary region increases the risk of dispersion of the iris pigment in the anterior segment of the eye and the associated increase in intraocular pressure up to the development of secondary glaucoma.

An intracapsular ring with an IOL fixation element is known, which is used for extracapsular cataract extraction with intraocular correction of aphakia with an elastic lens (ElIOL) with simultaneous implantation of an intracapsular stabilizing ring (VSC). The design of the VSK provides for the presence on the inside of the ring of at least two elements for fixing the ELIOL in the form of its bends of complex shape, located in opposite segments and forming loops of at least two turns with gaps between them, having dimensions close to the thickness of the ELIOL haptic, which allows to fix the planar haptics in the gaps between the turns of the loops of the elastic ring and to ensure a stable postoperative position of the lens, including in the absence of the posterior lens capsule (patent RU 2253411, IPC A61F 2/16, publ. 10.06.2005).

The disadvantages of this device include the absence of any mechanism for its fixation to the iris or sclera. Thus, this device cannot prevent the dislocation of the intraocular lens along with the capsular bag.

The technical problem solved by the invention is the creation of a device that eliminates the disadvantages of analogues for implantation into the lens capsule with severe weakness or the presence of defects in the ligamentous apparatus of the lens of various degrees to ensure the stability of the position of the intraocular lens (IOL).

EFFECT: prevention of dislocation of the intraocular lens in the capsular bag both during the operation and in the postoperative period due to reliable fixation of the arches of the capsular bag to the stroma of the peripheral zone of the iris.

The problem is solved, and the technical result is achieved by a device for implantation into the lens capsule, made in the form of an intracapsular segment, which is a ring segment with a length of 90° to 180°, made of plastic, having rings with holes at the ends, and in the middle part an element for fixing to iris, which includes two identical loops fixed on a segment of one of its sides, the tops of which are directed towards the center of the ring, while in the lower part, not reaching the arc of the ring segment, the loops are connected by an I-shaped transition, in the middle of which a slot is made with the possibility of pinching the iris tissue in it is similar to a cut in the haptic elements of the intraocular lens, designed to pinch the peripheral part of the stroma of the iris in it, while at the top of the loops of the fixing element a smooth bend is made with the formation between the plane of the ring segment and the plane of the loops of the fixing element of a distance varying in depending on the structure of the anterior segment of the patient's eye from 0.3 to 1.0 mm, and the length of these loops from the arc of the segment to the top of the loops is selected based on the possibility of removing the loop from the capsular bag under the iris, taking into account the size of the capsular bag and the size of the patient's capsulorhexis, and the length of the loops from the slot between them to the top is selected from the condition of ensuring the possibility of fixing the slots of the locking mechanism to the peripheral part of the stroma of the iris. According to the invention, in a particular case, the device is a ring segment with a length of 120°. The technical result is achieved as follows.

The design of the segment prevents dislocation of the intraocular lens in the capsular bag both during surgery and in the postoperative period by fixing the arches of the capsular bag to the stroma of the peripheral zone of the iris. Reliable and uniform fixation of the entire complex "IOL-capsular bag" is provided due to symmetrically located equidistant from the center zones of enclavation (infringement) of the stroma of the iris. At the same time, there is no need for suture fixation, which reduces the technical complexity of the operation, and also reduces the risk of developing hemorrhagic and infectious complications. The low invasiveness of manipulation is also ensured by the fact that the device can be implanted through a standard cataract incision of 2.4-3.2 mm. When using the device, there is no risk of an increase in astigmatism induced by the operation, since it does not require the formation of a large incision or expansion of the standard one, and the possibility of IOL inclination, which is characteristic for fixing the IOL to the sclera, is excluded.

The essence of the invention is illustrated by drawings, which show the inventive intracapsular segment.

In FIG. 1 a, b) - appearance of the intracapsular segment:

a) a top view with the specified dimensions for a particular case of execution, b) a side view;

In FIG. 2 - external view of the intracapsular segment, end view;

In FIG. 3 - location of intracapsular segments in the capsular bag;

In FIG. 4 - external view of the test sample of the intracapsular segment, top view.

The figures indicate:

1 - segment arc;

2 - loop of the fixing element;

3 - technological holes at the ends of the segment;

4 - a smooth bend with the formation of a distance between the plane of the ring segment and the plane of the loops of the fixing element (angulation zone);

5 - slot in the fixing element (similar to the iris-claw mechanism);

6 - arch of the capsular bag;

7 - edge of capsuloresis;

8 - part of the loop, located during implantation between the anterior lens capsule and the iris;

9 - part of the loop, located during implantation under the anterior capsule of the lens;

S is the distance between the plane of the ring segment and the plane of the loops of the fixing element, formed by a smooth bend at the top of the loops of the fixing element, varying depending on the structure of the anterior segment of the patient's eye from about 0.3 to about 1.0 mm.

The intracapsular segment is applied as follows.

The intracapsular segment (Fig. 1) can be implanted both immediately after capsulorhexis, and immediately before implantation of the intraocular lens, as well as after it. Implantation is possible when the IOL is dislocated in the capsular bag in order to reposition it and securely fix it. A segment or several segments are implanted manually, through a standard corneal, scleral or sclero-corneal tunnel 2.4-3.2 mm.

The segment is placed in the roof of the capsular bag (Fig. 3). At the same time, a distance S from 0.3 to 1.0 mm is provided between the plane of the ring segment and the plane of the loops 2 of the fixing element, depending on the structure of the anterior segment of the eye, implemented due to the presence of a smooth bend 4 (angulation zone) at the top of the loops of the fixing element. This distance corresponds to the average distance between the iris and the capsular bag in a pseudophakic eye and, accordingly, prevents the displacement of the capsular bag with the intraocular lens after device implantation and the associated change in postoperative refraction. Loop 2 of the fixing element due to the presence of zone 4 of a smooth bend (angulation) is removed from the capsular bag under the iris.

The length of the loops 2 from the arc of the segment to the tops of the loops (part 9 of the loop) can be 2.5 mm to ensure the possibility of removing the loop from the capsular bag under the iris with an average size of the capsular bag of 10 mm and an average size of capsulorhexis of 5 mm, and the length of each of the loops from the tops to the slots (part 8 of the loop) can be 1.75 mm to provide a distance of 8.5 mm between the two fixation zones to the peripheral part of the iris stroma (as implemented in the iris-claw IOL). For eyes with myopia or hypermetropia, these dimensions may vary in proportion to the change in the size of the capsular bag.

In cross section, the segment has the shape of a circle, inside a solid one, the diameter of which can vary depending on the parameters of the eye, averaging 0.3 mm.

After implantation of the intracapsular segment in the projection of the location of the fixing element, paracentesis is performed in the limbus zone and using an additional instrument (for example, a Sinskey hook) inserted through the paracentesis, the iris tissue is fixed in the slot 5 of the fixing element (Fig. 5). Additional suture fixation of the implant to the sclera is possible through technological holes 3 at the edges of the main arc of the segment.

An example of the application of the claimed device.

Patient B. has hypermetropia and a proportionally small anterior chamber. During phacoemulsification of the cataract, a local defect of the zinn ligaments with a length of one quadrant was revealed. To prevent further tearing of the zinn ligaments, as well as late dislocation of the IOL at the stage of phacoemulsification, a segment of polymethyl methacrylate 120° long was implanted with angulation in it, providing a distance between the plane of the ring and the plane of the fixing element of 0.3 mm.

Indications for implantation are weakness of the ligamentous apparatus of the lens of varying degrees, including generalized, defect of the ligamentous apparatus of the lens of any size, the need for additional fixation of the IOL.

The advantages are the presence of a locking mechanism, low trauma and invasiveness when fixing the proposed device, no need for additional sutures when fixing the proposed device to the iris, no risk of weakening the fixation over time.

Claims (2)

1. A device for implantation into the lens capsule, made in the form of an intracapsular segment, which is a ring segment with a length of 90° to 180°, made of plastic, having rings with holes at the ends, and in the middle part - an element for fixing to the iris of the eye, which includes two identical loops fixed on a segment of one of its sides, the tops of which are directed towards the center of the ring, while in the lower part, not reaching the arc of the ring segment, the loops are connected by an I-shaped transition, in the middle of which a slot is made with the possibility of pinching the rainbow tissue in it shell is similar to a slot in the haptic elements of an intraocular lens designed to pinch the peripheral part of the stroma of the iris in it, while at the top of the loops of the fixing element a smooth bend is made with the formation between the plane of the ring segment and the plane of the loops of the fixing element of a distance that varies depending on the structure of the anterior segment pa eyes from 0.3 to 1.0 mm, and the length of these loops from the arc of the segment to the top of the loops is selected based on the possibility of removing the loop from the capsular bag under the iris, taking into account the size of the capsular bag and the size of the patient's capsulorhexis, and the length of the loops from the slot between them to the top is selected from the condition of ensuring the possibility of fixing the slots of the locking mechanism to the peripheral part of the stroma of the iris. 2. A device for implantation into the lens capsule according to claim 1, characterized in that it is a segment of the ring with a length of 120°.

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