Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
  • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
  • A61F2/02—Prostheses implantable into the body
  • A61F2/14—Eye parts, e.g. lenses, corneal implants; Implanting instruments specially adapted therefor; Artificial eyes
  • A61F2/16—Intraocular lenses
  • A61F2/1694—Capsular bag spreaders therefor

Definitions

• the present invention relates to capsular rings which are intended to be implanted in the capsular bag, after the removal of the lens affected by cataracts, in association with an intraocular lens intended to replace the lens.
• tension rings have been adopted to maintain the shape of the capsular bag and to limit the post-operative retraction thereof.
• capsular rings have been made to combat opacification of the posterior capsule of the capsular bag which is at the origin of the secondary cataract making the posterior capsule opaque and necessitating the opening thereof by YAG laser beam. to restore visual acuity.
• Opacification of the posterior capsule has two aspects: first there are the fibroses corresponding to an in situ metaplasia of the anterior epithelial cells. It is a complication that can reach 40% of cases of cataract removal with replacement of the lens. It turns out that fibrosis has little effect on visual acuity. There are also Elschnig pearls that form from germ cells remaining at the equator of the capsular bag after surgery. These cells migrate along the posterior capsule and form opaque pearls which are the main cause of the decrease in visual acuity linked to the opacification of the posterior capsule.
• Tension rings are normally ineffective in constituting a barrier to cell migration because they are often devoid of sharp edges or square edges and / or of too small axial or anteroposterior dimensions allowing the insertion of zonular fibers. on the capsule thus maintaining an open germinal equatorial zone.
• Anti-opacification capsular rings are also known.
• the vast majority of anti-clouding capsular rings offered on the market are made of polymethylmethacrylate (PMMA) which is a rigid and hard material allowing to obtain sharp edges, or square edges, effective as a barrier to cell migration.
• PMMA polymethylmethacrylate
• the handling of such rings by the surgeon poses a serious problem because of their very high rigidity and their high elasticity which makes them dangerous during introduction and deployment in the capsular bag. Indeed, when a clamp is used, after passing through a corneal or sclerocorneal incision, a first end is introduced by the rhexis into the capsular bag over approximately 270 °, then the remaining part is folded back inside the rhexis before being released.
• the ring When an injector is used, the ring is positioned in a tube and moved by means of a sliding hook passing through the hole of the eyelet located at one and / or the other end of the ring.
• the strand of the ring of rigid material, such as PMMA, after loosening, can violently strike the equatorial zone of the capsular bag with a risk of damage to the bag or tears of the zonules attached to the outside of the bag capsular at the equator.
• capsular rings must necessarily be of the open type. Indeed, configured in closed rings, the corneal or sclerocorneal incision would be far too large to allow rapid healing expected by surgeons and their patients.
• EP-A- 0.884.031 describes an open capsular ring in general C shape with sharp edges to produce a "wedge" effect during the retraction of the capsular bag, which makes it possible to block the migration of epithelial cells.
• the capsular rings described in this document have a substantial axial or anteroposterior width of 0.7 mm and a width of 0.2 mm to cover the entire width of the equatorial zone of the capsular bag, from which the cells propagate. .
• a capsular ring of large axial width opposes fibrosis and prevents the capsular joining or symphysis essential to stop the migration of epithelial cells, or even Elschnig pearls, on the posterior capsule inside the zone corresponding to the periphery of the optics of the intraocular lens implanted to replace the lens.
• the symphysis is also advantageous in that it allows stabilization of the intraocular lens positioned in the bag.
• the object of the invention is a capsular ring which provides a barrier to equatorial cell migration to the posterior capsule which is capable of overcoming the drawbacks of known anti-clouding capsular rings.
• a capsular ring implantable in the equatorial region of a capsular bag after removal of the cataract, comprising an open or closed annular body, the annular body having a sharp edge on the large majority of the circumference and an axial width of between approximately 0.3 and 0.6 mm, and preferably approximately 0.5 mm, characterized in that the annular body, including the sharp edges, is made of rigid material on the majority of the circumference, and in that the annular body comprises at least one junction of flexible material between two segments of the annular body of rigid material.
• the junction (s) made of flexible material constitutes a preferential folding zone.
• a first end, called the front end, of the ring is introduced and the ring is pushed by rotating it in the bag until introduction about three-quarters of the annular body.
• the annular body is divided by the junction (s) of flexible material into two or more rigid segments allowing an easier gesture to control by avoiding large amplitude movements liable to produce lesions.
• the sharp edges of the segments extend over at least about 90% of the circumference of the annular body.
• these junctions made of flexible material providing increased flexibility to allow the ring to better adapt to the configuration of the tube, typically rectilinear, or with a very large radius of curvature with respect to the radius of the capsular ring, without risk of cracking of the annular body, each of the segments of rigid material of the implant being relatively weakly stressed.
• the first end, or front end, of the capsular ring with an open contour comprises a terminal part, without eyelet, of flexible material and slightly re-entering which reduces, even eliminates, the risk of perforating the bag
• the other, or second, end, or rear end which is preferably provided with an eyelet tab.
• a single junction When a single junction is provided, it is preferably arranged about 300 ° from the front end.
• three junctions are provided, arranged at approximately 120 ° from each other.
• Such a ring is particularly intended for implants whose optics with a square peripheral edge, that is to say with at least one sharp edge and two or more haptic elements capable of bearing on the current part of the rigid segments of the capsular ring, ensuring both good stability and good centering.
• the periphery of the optical part it provides a second effective barrier against cell migration thanks to the symphysis of the anterior and posterior capsules, and this despite an axial width of the capsular ring sufficient to block the proliferation of epithelial cells in the equatorial zone.
• a closed capsular ring preferably two junctions made of flexible material are provided which allow a marked ovalization, or flattening, of the implant and therefore the introduction of the ovalized, or flattened, ring through a corneal incision or sclero-cornea much smaller than what can be done with a closed contour ring made of rigid material.
• Such a capsular ring with the vast majority of its sharp edges made of rigid or hard material is more effective as a barrier to cell migration than a capsular ring with closed outline made of flexible material.
• FIG. 1 shows a first embodiment of a capsular ring, according to the invention, with open outline
• FIG. 4 is an elevational view of the capsular ring of Figures 1 to 3;
• FIG. 5 shows the first embodiment implanted in the capsular bag after retraction of the bag and symphysis of the anterior and posterior capsules;
• FIG. 6 shows a second embodiment of a capsular ring according to the invention, with open outline
• FIG. 7 shows a folding mode according to the first embodiment
• FIG. 8 shows a third embodiment of a capsular ring, according to the invention, with closed contour
• FIG. 9 shows a set of the capsular ring open contour in one piece with an intraocular lens.
• the capsular ring 10 shown in Figures 1 to 5 comprises an annular body 11a open contour, substantially circular.
• the diameter of the ring in the state of rest will be greater than that of the capsular bag in which it is intended to be implanted and in practice of approximately 10.5 to 11.5 mm.
• the running part of the annular body links a first end 13, a second end 14. In the state of rest, the ends are spaced circumferentially from one another by about 0.5 mm.
• the annular body has a substantially rectangular radial section whose axial dimension is approximately 0.5mm, and which is greater than the radial dimension which is between 0.1 and 0.3 mm and preferably approximately 0.15 mm (see Figure 3).
• the external surface 15 of the annular body is preferably substantially a straight cylinder extending between two sharp edges or square edges 16 and 17.
• the first end 13 which, in practice, is the front end by which the capsular ring is introduced into the capsular bag through a sclerocorneal incision and the rhexis in the anterior capsule, is made of flexible material, so that '' in case of contact of its free edge with the tissues of the capsular bag, the risk of accidental perforation is reduced. In addition, its flexibility will facilitate its passage over the equatorial zone of the capsular bag when the ring is gradually pushed circumferentially along the equatorial zone of the capsular bag.
• This first end is slightly curved and re-entrant with the rounded free edge thicker than the current part of the body of the ring.
• the second end 14 comprises an eyelet tab of the type known per se offset inwards and capable of receiving the hook of a handling instrument making it possible to modify the position of the ring in the capsular bag or for hooking it to a capsular ring injector rod, also known per se.
• the annular body 11 is largely made of a rigid or hard material, with a low hydrophilicity or hydrophobic rate, and in particular PMMA.
• the annular body 11. comprises two annular segments 18A, 18B, the first annular segment 18A preferably having a circumferential extent greater than about 260 ° and less than about 320 ° and preferably about 300 ° and the second annular segment 18B having a circumferential extent of about 55 °.
• the junction or block 19 has a rectangular section, preferably square, with an outer surface having substantially preferably the shape of a straight cylinder extending between two sharp edges or square edges in continuity with the sharp annular edges 16, 17 of the segments.
• the substantially square section of the junction 19 is larger than that of the current part of the annular segments, and therefore of the annular body, and has an axial dimension of approximately 0.4 to 0.5 mm and a radial dimension of approximately 0.4 to 0.5 mm, the parts of the segments 18A, 18B adjoining the junction having the same cross section as the latter
• the circumferential extent of each of the junctions will be between 0.5 and 6% of the circumference of the ring.
• the opposite edges of the parts adjoining the junction converge radially towards the inside of the annular body.
• the outer surface of the annular body preferably preferably has the shape of a straight cylinder from one end to the other, whether it is the junction (s) of flexible material or the segments of material rigid, including the parts adjoining the junctions.
• the capsular ring according to this embodiment is in practice made by selective chemical structural modification, according to the process described in EP 1003446 from an annular body whose geometry corresponds to that of the final annular body in particular by molding, machining from a puck or blank as used for the manufacture of intraocular lenses.
• the initial annular body is made of flexible material and then the hardness or rigidity of the zones corresponding to the desired segments is obtained by the selective chemical structural modification of the corresponding parts of the initial annular body.
• the flexible material of the annular coips that is to say the junction (s) and the first end, are preferably obtained from random methyl methacrylate-methacrylate and hydroxyethylmethacrylate (MMA-HEMA) copolymers crosslinked by addition of a multifunctional agent such as diethylene glycol dimethacrylate.
• the rigid material of the lens is preferably based on PMMA.
• the initial annular body is made of rigid material and then the zones corresponding to the desired junctions are obtained by selective chemical structural modification. In both cases, there will be covalent bonds between the flexible material and the rigid material of the annular body. Thanks to this manufacturing process, the structural integrity of the ring is also much higher than what could be obtained by conventional methods.
• the flexible material constituting the junction (s) may have a glass transition temperature of approximately 35 ° C., so that the ring has a folded configuration facilitating its insertion through the incision and the rhexis and another specific configuration deployed corresponding to that of the ring implanted in the capsular bag.
• the flexible material can be a shape memory material.
• the first segment 18 A is pushed around the equatorial zone until the junction 19 reaches the rhexis and then the second segment 18B is folded inside the capsular bag in an oblique plane or transverse to the general plane of the first segment 18 A before being released, thus allowing the relatively short second segment 18B to find its place in the equatorial zone and this without risk of damage to the bag or tearing of the zonules thanks to the extent reduction of the second segment and the damping effect of the flexible material junction which reduces the impact of the segment with the tissue of the capsular bag.
• the diameter of the capsular ring is chosen so that it is slightly in compression against the equatorial zone of the capsular bag at the time of its implantation. This compression would have the effect of closing the capsular ring by bringing its ends closer together, the first end 13 passing outside the second end 14 thus forming a very slight recess at the level of the covering of the ends 13, 14, as shown in Figure 5.
• the resulting discontinuity is minimized thanks to the small thickness and the inherent flexibility of the first end 13 which tends to collapse radially between the end 14 and the capsular tissue at the equator.
• the capsular bag tends to shrink, of the order of 0.5 mm to 1.5 mm in diameter, which has the effect of increasing the length of covering.
• Such a capsular ring can also be implanted by an injector of the type known per se.
• an injector has a substantially rectilinear or even curved housing with a very large radius relative to that of the capsular ring. Thanks to junction 19, the stresses induced by the substantially rectilinear or slightly curved deployment of the ring are greatly reduced, thus minimizing the risk of cracking and in particular when the capsular ring is loaded in the injector and delivered in sterile packaging intended to be opened at the time of use, that is to say months after their packaging.
• an intraocular lens 31 of the type described in patent FR-A-2,745,711 with three haptic elements 32 with large window extending from the periphery of the optics 31 forms an assembly with the capsular ring according to the first embodiment.
• the ring is therefore also advantageously used for centering and positioning the intraocular lens in the capsular bag.
• the axial width of the interior surface of about 0.5 mm according to the preferred embodiment, constitutes a good support for the haptic elements of the intraocular implant.
• the anterior and posterior sheets or capsules come together. Since the axial width of the capsular ring is preferably limited to about 0.5 mm, i.e. between 0.45 and 0.55 mm, it does not prevent the symphysis of the capsules and more particularly at the periphery of the optical part of the intraocular lens. As shown in FIG. 5, the optical part 33 of the intraocular lens 31 has, on the posterior surface, at least one sharp edge or square edge 34 which penetrates slightly into a fold of the tissue of the posterior capsule thus forming a second barrier to the migration of epithelial cells, or Elschnig beads, thus preventing clouding of the posterior capsule behind the optic element and the formation of a secondary cataract.
• the capsular ring according to the embodiment of Figure 6 differs from the embodiment of Figures 1 to 5 only by the presence of three junctions.
• the annular body has a junction 19B arranged diametrically opposite the ends 13, 14 of the open annular body, two other junctions, 19 A, 19C being located at approximately 120 ° from the junction 19B.
• the plurality of junctions are regularly spaced around the circumference of the open ring.
• the junctions 19A and 19C are therefore at about 60 ° from the respective ends 13, 14.
• the main part and the junctions made of flexible material have the same radial section.
• the two relatively short segments 24A, 25A are first folded preferably inwards (but possibly outwards) of the two relatively long segments 24B, 25B and the segments are brought closer or pivoted around junction 19B.
• the short segments 24A, 25 A can simply be brought towards each other but, preferably, a pair of segments 25A, 25B are slightly offset (in the axial direction) behind the other pair of segments 24A, 24B in order to minimize the size of the segments 24A and 24B being more in line with the segments 25B, 25A (not shown) and this thanks to the flexibility of the central junction 19B.
• the four segments are therefore introduced simultaneously through the incision and then they enter the capsular bag through the rhexis. It is then that the two short segments 24A, 25A are preferably released first, successively or simultaneously, then the two long segments 24B, 25B folded around the junction 19B are released. Thanks to a plurality of junctions, the surgeon has different manipulations and possible sequences for the introduction and deployment of the segments in the capsular bag. In addition, there remains the possibility of introduction by means of an injector.
• the capsular ring 10 has a closed contour. To this end, it preferably comprises two junctions 19 made of flexible material diametrically opposite.
• the configuration of the segments 18A, 18B, in rigid material as well as the junctions 19 in flexible material is that described with reference to FIGS. 1 to 5, except as regards the extent of the segments and the removal of the ends.
• Such a ring has the advantage of maintaining its diameter despite the retraction of the capsular bag on the one hand and on the other hand, thanks to its sharp edges or square edges along the segments of rigid material, it provides an excellent barrier to the cell migration, given the perfect continuity of the two sharp edges around the entire circumference of the ring.
• Such a ring with closed contour can however be introduced by an incision of relatively small size, of the order of 3.5 mm, although necessarily larger than that necessary for the introduction of a capsular ring with open contour which is of 'order of 2.5 mm, thanks to the two junctions 19 made of flexible material which allow the ovalization or flattening of the ring with a major axis passing through the clamped junctions between the jaws of a clamp.
• the ovalized or flattened ring is introduced into the capsular bag by one of these junctions, passing through the cormian or sclerocorneal incision and then through the rhexis, continuing to push on the other junction, the part of the ring present in the bag will open and come to conform to the shape of the equator. It is then necessary to push further on the rear junction so as to make it enter the circle of the rhexis before releasing it so that it takes its place in the capsular bag.
• the junctions act as a shock absorber to absorb part of the energy released when the ring is released into the capsular bag.
• the implantation of the ring is followed by the implantation of the intraocular lens, in accordance with current practice with forceps or injector.
• the haptic elements of the intraocular lens are in contact or bear against the interior annular surface of the current part of the ring, that is to say offset with respect to the junctions and the parts of the segments adjoining them.
• an optic 40 made of flexible material is formed in one piece with the capsular ring 10. In the rest position of this capsular ring / intraocular lens assembly, the optic is slightly off center with respect to the axis of the capsular ring. ;
• the link 45 comprises a first straight haptic part 46 extending at an oblique angle, preferably neither radial nor tangential, from the periphery of the optics 40 followed by a second haptic part 47 curved with a recess 48 open circumferentially towards the second end of the ring before joining the inner edge of the first end 13 of the ring 10.
• the recess 48 of complementary shape is capable of receiving the second end of the eyelet tab when the two ends come together, following the postoperative capsular retraction. He goes . It goes without saying that such an assembly can also be produced by selective chemical modification.
• this capsular and optical ring assembly is also made easy by the junction 19 between the segments 18 A, 18B.
• This implantation begins with the introduction of the ring, not by its first end 13 but by its second end 14 and once the capsular ring is largely in place in the equatorial zone, the folded optics and the haptic part are released, allowing the optics to find its place and kept centered relative to the capsular ring implanted in the equatorial zone, and therefore, centered relative to the capsular bag.
• the capsular ring can be impregnated beforehand with an anti-proliferation product and in particular 5-FU.
• the impregnation and release process after implantation of the ring is preferably in accordance with the teachings of patent application WO 98/25652.

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• Health & Medical Sciences (AREA)
• Ophthalmology & Optometry (AREA)
• Cardiology (AREA)
• Oral & Maxillofacial Surgery (AREA)
• Transplantation (AREA)
• Engineering & Computer Science (AREA)
• Biomedical Technology (AREA)
• Heart & Thoracic Surgery (AREA)
• Vascular Medicine (AREA)
• Life Sciences & Earth Sciences (AREA)
• Animal Behavior & Ethology (AREA)
• General Health & Medical Sciences (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Prostheses (AREA)
• Materials For Medical Uses (AREA)

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• 2003
  • 2003-01-08 FR FR0300143A patent/FR2849592B1/fr not_active Expired - Fee Related
  • 2003-12-30 JP JP2004567802A patent/JP4372016B2/ja not_active Expired - Fee Related
  • 2003-12-30 CA CA002512606A patent/CA2512606A1/fr not_active Abandoned
  • 2003-12-30 EP EP03815709A patent/EP1581152A1/de not_active Withdrawn
  • 2003-12-30 CN CNB2003801096158A patent/CN100518691C/zh not_active Expired - Fee Related
  • 2003-12-30 WO PCT/FR2003/003942 patent/WO2004069101A1/fr active Application Filing
  • 2003-12-30 AU AU2003303901A patent/AU2003303901A1/en not_active Abandoned
  • 2003-12-30 US US10/541,673 patent/US20060235515A1/en not_active Abandoned

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