FR2469918A1 - Artificial crystalline eye lens - has thread forming hook acting as fixing component and resilient supporting thread - Google Patents

Abstract

The artificial crystalline lens has fixing and supporting components on diametrically opposite sides, to allow fitting in the crystalline capsule of the patient's eye. The fixing component is a hook (3) formed by a thread (5) and so secured on the transverse surface of the lens (2) that its apex (9) lies on a line through the centre of the lens and that of the supporting thread (4), which is also secured to the lens transverse surface. This thread is spread onto the outer surface of the lens, and is of elastic material. Thus radial movement is possible, allowing adjustment of the lens centre distance from the supporting thread to suit the size of the crystalline capsule in the eye.

Description

 Artificial crystal.

 The present invention relates to medicine and in particular to ophthalmology; it relates in particular to an artificial lens.

 One of the very important problems encountered in ophthalmology is that of vision correction after cataract surgery. There are several methods for making such a correction, for example the use of glasses or contact lenses. However, in the case of correction using glasses, the patient's vision does not become optimal, while the correction of vision using contact lenses is not supported well enough by all patients, especially at the advanced age at which cataracts are most widespread, in around 80 to 85% of cases.

 This is why scholars from many countries have sought other solutions to this problem. One of the solutions envisaged consists of an intraocular correction or the implantation of an artificial lens.

Different designs of artificial lenses are known, conditioned by the method of carrying out the operation.

 Thus, for example, an artificial crystalline lens is known comprising a lens provided with support and fixing elements. the two elements are generally identical and are constituted by legs in the form of loops of rigid material, fixed in the lateral surface of the lens, and the difference between them consists in that the fixing element comprises two projections intended to orient and retain the suture material (see USSR inventor certificate No. 563,174).

 Such a lens is intended to be implanted in the lens bag. However, at implantation, the center and the optical axis of the lens may be offset from the center of the pupil and from the optical axis of the eye, since the dimensions of the lens bag vary with the subject and that often they do not coincide with the dimensions of the artificial lens. It must be kept in mind that such a design requires a high-precision of realization of the constituent elements, in particular a great precision of the positioning of the legs of the fixing element, since their offset leads to an incorrect fitting of the lens, and consequently to its imprecise orientation relative to the vertical meridian of the eye.

 the installation of such a lens is carried out in the following manner.

After the opening of the anterior chamber of the eye, an incision is made near the root of the iris, at the location of the slit formed, the incision of the anterior lens capsule is made, and the the nucleus and the masses of the lens. Then a hole is formed in the anterior lens capsule, the artificial lens is implanted in the lens bag, then the legs of the fixing element are sewn to the edges of lri ~ cision of the iris.

 The disadvantage of such a procedure lies in the fact that a rupture of the anterior capsule may occur if the support element is hooked to the edge of the hole in the capsule, and that it is not no provision is made for individual choice of the artificial lens according to the dimensions of the patient's lens bag.

In the context of the invention, it is proposed to make and place the elements for supporting and fixing the artificial lens relative to the lens so that it is possible: to ensure a safe orientation of the lens by report to the vertical eye doctor to obtain perfect co-vision of the patient's artificial lens and lens bag; to make the requirements as regards manufacturing precision less stringent and to ensure the simplicity of the installation of the support element.

 the problem is solved by the fact that in an artificial lens comprising a lens and fixing and support elements fixed to said lens on diametrically opposite sides and serving to ensure the placement of the lens in the lens bag of the patient, according to the invention, the fixing element is a wire angle fixed in the lateral surface of the lens so that its apex is on the line passing through the center of the circumference of the lens and through the center of the element of wire support also fixed in the lateral surface of the lens, elongated along the circumference of the lens and made from a flexible material capable of allowing movement in the radial direction ensuring an adjustment of the distance between the center of the lens and wire support element according to the dimensions of the patient's lens bag.

 The advantage of such a design lies in the fact that the reciprocal arrangement of the top of the angle iron, the fixing element, the support element and the center of the lens always ensures correct orientation with respect to the median. vertical of the eye, that is to say that the warping specific to known devices is excluded.

The possibility of displacement of the support element in the radial direction allows; on the one hand, to make the requirements regarding the manufacturing precision of this element less stringent and to simplify its installation and on the other hand, it thus becomes possible to obtain a total correspondence of the dimensions of the artificial lens and dimensions of the patient's lens bag.

It is advantageous to separate + angle iron near its apex in the direction transverse to its sides so that the apex of the angle iron is arranged in a plane passing through the apex of the spherical surface of the lens, which gives the possibility to exclude warping of the lens in its vertical plane
In addition, it is most advantageous to separate the angle by forming an elbow, a part of which is perpendicular to the sides of the angle, and the second part of which is perpendicular to the first part of the elbow and lies in a plane passing through the top of the lens.

 At the top of the angle iron it is possible to make an eyelet to pass the suture material.

 In order to ensure a required arrangement of the lens with respect to the vertical meridian of the eye, it is necessary to provide on the lens, along an imaginary line passing through the top of the angle iron and through the center of the support element, distant marks at a distance of 1/3 of a radius from the edge of the lens.

The invention will emerge more clearly from the description of the concrete examples of embodiment of the artificial lens which will follow and from the process for its implantation and with reference to the appended drawings in which
FIG. 1 represents the front view of the artificial lens according to the invention
Figure 2 is a side view of the artificial lens according to the invention
Figure 3 shows another alternative embodiment of the artificial lens according to the invention
FIG. 4 represents in a conventional manner the eye of a patient during the measurement of the lens bag parameter, according to the invention
FIG. 5 shows the artificial lens during preparation for implantation, according to the invention
Figure 6 shows a reciprocal arrangement of the artificial lens in the lens bag of the patient's eye and the cent # re of the apple after orientation along the vertical meridian of the eye, according to the invention.

 FIG. 1 shows that the artificial lens designated as a whole by the reference numeral 1 comprises a lens 2 of any known structure, for example, convex-concave, as shown in FIG. 2 and fixing and support 3 and 4 respectively.

The fixing element 5 is an angle made from a wire 5, engaged by any known method in the peripheral lateral surface 6 of the lens 2 by its ends 7. On the diametrically opposite side is arranged the support element 4 which is a loop-shaped tab made from a flexible wire, for example, from an alloy of platinum and iridium. The ends 8 are engaged in the lateral surface of the lens - in a similar way to that of the fixing of the ends 7 of the fixing element 3.

The angle-shaped fixing element 3 and the leg-shaped support element 4 are arranged so that the apex 9 of the angle is placed on a line passing through the center of the lens 2 and the middle of the support element 4.

 The angle iron, in the upper part, is curved in the transverse direction from the side of the apex of the lens 2. In this case, as shown in FIG. 2, an elbow 10 is formed, made up of two parts, one of which is perpendicular at the sides of the angle and the other is perpendicular to the first and lies in a plane passing through the apex of the spherical surface of the lens.

 In addition to this, FIGS. 1 and 2 show that point marks 11 are provided on the lens, distant from the edge of the lens by a distance equal to 1/3 of its radius and arranged on a line passing through the top of the angle 3 and the middle of the leg 4.

 3 shows an artificial lens essentially similar to that shown in Figures 1 and 2 and therefore the reference numbers are the same, the only difference being that at the top of the angle there is an eyelet 12 for receiving suture material.

The implantation of such an artificial lens will be described below.
The implantation of an artificial lens in a lens bag is carried out as follows.

After extra-capsular extraction of the cataract through a basal iridotomy 13 (Figure 4) and a preequatorial section 14 of the anterior capsule in the empty lens bag, a special graduated spatula 15 is introduced, the end of which is approached by its equator 16 in the lower part of the eye and across the cornea the distance to the center of the pupil is determined 17.

 The support element for the artificial lens in the form of a loop tab 4 (FIG. 5) is spread or folded to obtain a distance to the center of the lens 18 corresponding to the distance separating the equator from the lens bag and the center of the apple.

After having chosen the required dimensions of the parameter, the artificial lens is introduced into the lens bag through the basal iridotomy 13 (FIG. 6) and the preequatorial section 14 of the anterior capsule so that the loop-shaped tab 4 reaches 1 equator 16 of the lens bag in the lower part of the eye and the angle 3 having an elbow-shaped flexion is sewn at the edge of the basal iridotomy. In the pupil region, a hole is made in the anterior capsule 20 of the lens bag using a diamond scalpel or using scissors.
Vannas.

 The axis 19 of the artificial lens is oriented along the vertical meridian of the eye, along the line "apex of the angle iron - point marks 11" brought to the lens 2 as a function of its deviation from the normal position (vertical), after which the center 18 of the lens and the center 17 of the pupil are made to coincide.

 The implantation is completed by sealing the operating section, by restoring the anterior chamber with balanced solutions. We water the eyeball with a solution of atropine. For prophylactic purposes, antibiotics and corticosteroids are introduced below the conjunctiva.

 As examples, two examples of implementation will be described below.

Patient A: Age 22, driving profession.

 He entered an ophthalmic clinic on June 27, 1978. Diagnosis: traumatic cararact of the right eye, scarring of the cornea, holy left eye, emmetropia.

State at entry - Right eye: visual acuity equals sensation
visual at correct projection, auto-ophthalmoscopy and cobalt test are positive, PO = 13 mm of mercury.

 The appendages of the eye are not changed, the conjunctiva is "quiet". On the cornea there is a small scar passing through all the layers. The anterior chamber is shallower than that of the left eye.

The iris is not modified. The sloe is round, of medium width, the reaction to light is strong. The lens is cloudy in all the layers in which the swelling phenomena are manifested. The angle of the anterior chamber is open, of medium width, the trabecula is not pigmented. Electronic tonography: PO = 13; C = 0.34
F = 0.595; Becker's coefficient = 38.2.

 Echobiometry data: the length of the front-rear axis of the eye is 23.32 mm. The refraction of the cornea is equal to 44 diopters.

 An artificial lens was manufactured, the optical power of which was 61.9 diopters (measurements taken in air).

 - Left eye: no pathological transformation.

 Visual acuity is 1.0.

 The operation of the right eye was carried out on June 28, 1978. it is an intracapsular implantation of an artificial lens according to the method described # above.

On the operating table, a 1% atropine solution was introduced into the eye several times.

 Clinical course of the postoperative period.

 On the day of the operation, the patient is allowed to walk, eat normally, and has been prescribed the following treatment: eye drops three times a day: 1% atropine solution, corticosteroids and disinfectants for 'internal use butadione tablets (Butadioni)' and dimedrol (Dimedroli) 1 tablet three times a day.

 State of the eye which underwent the operation - the day of ltoEeration: hyperemia of the conjunctiva, the corneal cut is well adapted by a supramid suture (ten zeros); low descemetitis; the anterior chamber is deep, the liquid is transparent. The iris is calm "the pupil is 3 mm wide and round; near the upper edge of the limbus we see an iridotomy at the edge of which is fixed a fixing element in the middle; the artificial lens is in the bag to crystalline, its position relative to the axis of the vertical meridian of the eye is correct.

- the following days (from 1 to 5 days after the operation)
the hyperemia of the conjunctiva has almost disappeared, the phenomena of descemetitis have disappeared, the pupil has widened to 6.5 mm in diameter, it is round; on the bottom of the reflex of the eye we see the whole lens and the ends of the support and fixing elements which are engaged in the edge of the lens, we see the point marks made on the lens and the hole in the anterior capsule 3.5 mm in diameter with irregular edges. The posterior capsule is disposed at a certain distance from the rear surface of the lens.

the glass body is transparent. The fundus: the optical disc, the yellow spot and the periphery of the fundus are without pathological changes.

- the day of the exeat (July 3, 1978): visual acuity - was equal to 0.4 with correction - cyl 2.0D, to 0.8.

On September 13, t978, the corneal suture was removed.

Visual acuity was 0.9, with correction + 0.5D, equal to 1.0.

The right eye was calm, the scarring of the cornea was almost invisible. The anterior chamber was deep, the liquid was transparent. The apple was round, in the center of 2.5 mm in diameter, it reacted to light. 'the. edges of the hole in the anterior chamber were invisible. In the limbus we saw the iridotomy with the fixing element sewn on its edges. Iridodonesis was absent.

 In the pupil region we saw the lens, whose front and back surfaces were clean.

The rear capsule was transparent. The glass body was transparent. The optical disc, the yellow spot and the periphery of the fundus were unchanged.

 Gonioscopy: the angle of the anterior chamber was wide, the trabecula was not pigmented, adhesions at the corner were absent.

Electronic tonography: PO = 15; C = 0.4
F = 1.5; Becker's coefficient = 37.5.

 The visual field was within normal limits. The view was binocular.

 The patient continues to work as a driver and his lifestyle is normal without limitation of manual work, the position of the head and the body. The duration of surveillance - was nine months.

Patient P: age 78, writer.

 he entered an ophthalmological clinic on December 15, 1976, with the following diagnosis: cataract "in a pot" not "pond" on the right eye; Beginning cataract on the left eye.

- on the day of entry into the clinic: the visual acuity of 11 right eye was equal to the perception of light with a correct projection, that of the left eye, equal '' 0.6 to 0.6 a correction n did not make the view better.

- Right eye: the appendages of the eye were unchanged, the conjunctiva was calm, the cornea was transparent and shiny; the anterior chamber was of medium depth, the liquid was transparent; the iris was subatrophic; the apple was round, its diameter being 2 mm; the turbidities in the lens were mainly located below the rear capsule. The back of the eye resisted ophthalmoscopy. PO = 14, C = 0.15, F = 0.41, Becker's coefficient = 93. The auto-ophthalmoscopy and the cobalt test were positive.

 Gonioscopy: the angle of the anterior chamber was of average width. The trabecula was moderately pigmented. The refraction of the cornea was 44.5 diopters. The echobiometry, that is to say the length of the front-rear axis of the eye was equal to 24.1 mm. We made a special crystalline-artificial lens with an optical power (in the air) of 61 diopters.

- Left eye: the changes in the lens below the rear capsule were not significant.

 The right eye operation was performed on December 16, 1976. An intracapsular implantation of the artificial lens was performed using the procedure described above.

During the operation and during the postoperative period there were no complications.

QostoEeratory Period:
From the day of the operation, the patient was allowed to walk and eat normally. He was prescribed the following treatment: eye drops 3 times a day, corticosteroids, disinfectants and vitamin drops.

For internal use, tablets were prescribed to be taken three times a day: Butadioni - 0.15 g and Dimedroli - 0.05 g.

Given that on the first postoperative day there was a hypertonic syndrome, the patient was prescribed. the
Diacarbi at a rate of 0.25 g twice a day for two days, after which the intraocular pressure became normal and no longer rose.

Eye state to be ventilated at the time of the operation 1 the operation the conjunctiva was in a state of hyperemia, the epithelium of the cornea was edematous, we observed a descemetitis.

The edema of the corneal epithelium disappeared 3 days later, the discemetitis, 4 days later (day of exeat). The corneal cut was well adapted by a continuous supramid suture (ten zeros). The anterior chamber was deep; in this room the effect of Tyndall was gradually canceled in the space of 4 days. The pupil was 3.5 mm, the iridotomy was seen near the upper edge of the limbus with the attachment element sewn. In the pupil region in the optical section we could see the lens of the lens, its surfaces were clean.

 Bes days which followed (from 1 to 4 days after the operation) The hyperemia of the conjunctiva has almost disappeared, the edema of the corneal epithelium has also disappeared, the effects of descemetitis have almost disappeared. The pupil was round in the center and had a diameter of 3.5 mm, there was no diridodonesis, the edges of the hole of the anterior capsule were visible in certain places near the edge of the pupil. The posterior capsule was transparent.

The glass body was transparent. The optical disc, the yellow spot and the periphery of the fundus were unchanged.

 on the day of the exeat, December 20, 1976, the visual acuity of the right eye was 0.4 with correction cyl 5.0D, ax 1800.

During the review which took place on February 14, 1977, it was found
visual acuity of the right eye equal to 0.2 with correction of 3, oD = 0.9
on August 1, 1977, the visual acuity of the right eye was equal to 0.5 with correction of 0.75 cyl - 2.0D ax 950 = 1.25.

During the examination on August 1, 1977 it was found that
the right eye was calm, the scarring in the corneal part of the limbus was almost invisible.

The cornea was transparent and shiny. The anterior chamber was deep, the liquid was transparent. The iris was subatrophic. The apple was round in the center and 2 mm in diameter. In the limbus we saw (only in case of ~ raising of the upper eyelid) the iridotomy with sewn fixation element. In the pupil region we saw the lens of the lens; its surfaces were clean. The rear capsule was transparent at a distance from the rear surface of the lens. The glass body was transparent. The fundus, the optical disc, the yellow spot and the periphery of the fundus were without pathological changes.

 Gonioscopy: the angle of the anterior chamber was wide, the trabecula was moderately pigmented, there were no adhesions at the corner.

Electronic tonography: PO = 16; C = 0.3
F = 1.42; Po / c = 53.

 The visual field was within the limits of the standard.

- Left eye: visual acuity had decreased to 0 2, it
could not be corrected due to the increase in
turbidity of the lens.

 The patient continues his activities as a writer, goes skiing, regularly visits the swimming pool.

 The monitoring period is 2 years and 3 months.

Claims (5)

REVEEDICATIONS  1. An artificial crystalline lens comprising a lens and support and fixing elements fixed to said lens on diametrically opposite sides and used for placing the lens in the lens bag of a patient, characterized in that the lens element fixing is a wire angle fixed in the lateral surface of the lens so that its apex is on a line passing through the center of the circumference of the lens and the center of the wire support element, also fixed in the lateral surface of the lens, stretched along the length of the circumference of the lens and produced from a flexible material for displacement in the axial direction ensuring an adjustment of the distance between the center of the lens and the support element wire, depending on the dimensions of the lens bag of the patient's eye. 2. An artificial crystal according to claim 1, characterized in that the angle iron, near its apex, is spaced in the transverse direction with respect to its sides so that the apex of the angle iron is disposed in a plane passing through the apex of the spherical surface of the lens.  3. An artificial crystal according to claim 2, characterized in that the angle iron, near its apex, is separated by forming an elbow, a part of which is perpendicular to the sides of the angle iron, and the second part is perpendicular to the first part of the elbow and lies in a plane passing through the top of the lens.  4. An artificial lens according to any one of claims 1, 2 or 3, characterized in that at the top of the angle iron there is an eyelet for the passage of the suture material.  5. An artificial crystal according to any one of claims 1, 2, 3 or 4, characterized in that on the lens, along an imaginary line passing through the top of the angle iron and the middle of the support element, are made marks distant from the edge of the lens at a distance of 1/3 of the radius thereof.