FR2704422A1 - Ocular implant - Google Patents

Abstract

Ocular implant intended to be arranged in an orbit (eye socket) after enucleation or evisceration. According to the invention, the core (1) is covered at least partly by a coating (2) of colonisable material held by a rod (3) of biocompatible material. Applications: obtaining correct fixation of the oculomotor muscles on the prosthesis.

Description

EYE IMPLANT
The present invention relates to an eye implant or prosthesis intended to replace an eyeball after enucleation or evisceration.

Unfortunately, such operations are often necessary following illness or injury. In an enucleation operation, the whole eye is extracted from the orbit while in evisceration, the scleral shell is kept in the orbit.

 In order not to leave the orbit empty, it has been known for a very long time to insert into the orbital cavity a prosthesis of variable shape (PMMA sphere, tunnel implant, etc.) These prostheses remain stationary and have only one purpose aesthetic.

In order to make the prosthesis closer to a natural eye, it has already been proposed to constitute the implant by a silicone core, biocompatible material, on which the oculomotor muscles are sutured. The nucleus is covered with a shell representing the upper surface of an eye with the pupil, the iris and the cornea. However, if the silicone is biocompatible, it cannot be colonized by the vascularized tissues.

 It has already been proposed to cover the silicone core with a material that can be colonized by the connective tissues such as expanded polytetrafluoroethylene (P.T.F.E. e). Thus, some time after implantation in the orbital cavity, the muscles cling to the implant and move it at the same rate and in the same direction as the other normally functioning eye.

However, this covering practically requires either a bonding of the colonizable coating, or a seam. Bonding is incompatible with absorption phenomena in a microporous body, the adhesive clogging the micropores and being able to inhibit the colonization mechanism. Sewing is not a satisfactory process since expanded products tend, when a hole is drilled, to tear under the slightest traction.

The object of the present invention is to overcome this drawback.

According to the present invention, the ocular implant comprising a core and at least partial covering by a colonizable material is characterized in that the coating is fixed to the core by an elastic rod of biocompatible material inserted in a groove.

The rod can be made of silicone or PMMA, for example, the rod
PMMA being split to give it elasticity.

It is thus possible to cover the nucleus of generally spherical shape with a layer of microporous material which can be colonized by vascularized tissues and to attach to this layer, by colonization, the oculomotor muscles, which at first are sutured.

According to another characteristic of the invention, the core of the ball or implant consists of silicone, hydroxyapatite or PMMA.

 Hydroxyapatite is a low density microporous body obtained from coral or synthetically which is itself colonizable.

Other characteristics and advantages of the invention will appear during the description which follows of particular embodiments, given only by way of nonlimiting examples, with reference to the drawings which represent: - Figure 1, a view in section of an implant according to the invention; - Figure 2, a perspective view of another embodiment; - Figure 3, a view of an implant inside an orbital cavity: - Figures 4 and 5, a view in vertical section and in perspective of an implant entirely covered with colonizable tissue.

In FIG. 1, it can be seen that the implant is of generally spherical shape and of dimensions adapted to the dimensions of the orbital cavity. It consists of a core 1 which can be made of silicone or hydroxyapatite for example. The core 1 is covered at its upper part by a cap 2 of colonizable material such as expanded P.T.F.E. The cap 2 is molded on the core. But, to ensure its adhesion, it is held in place by an O-ring 3 made of biocompatible material which is inserted elastically in a peripheral groove 4.

Of course, the presence of layer 2 is linked to the geometry of the attachment points of the muscles and, in certain cases, it is possible to use the arrangement of FIG. 2 on which layer 2 surrounds the central part of the core on which it is maintained by two rods 3. This layer 2 is, in any event arranged so as to be opposite the attachments of the oculomotor muscles after implantation in the orbit.

Such an implantation is represented in FIG. 3. The core 1 is introduced into the orbit 5. the muscles 6 are sutured on the layer 2 which they will gradually colonize. In the front part of the implant 1 is fixed a connecting rod 7 allowing the fixing on the implant of a cover 8 reproducing the shape and the colors of a natural eye.

 It is possible, as shown in Figures 4 and 5, to completely cover the core 1 with a colonizable material 2 and to maintain this coating by a rod 3 of biocompatible material.

 It goes without saying that many variants can be made, in particular by substitution of equivalent technical means, without departing from the scope of the invention.

Claims (2)

Biocompatible CLAIMS fitting into a groove (4). (2) is fixed to the core (1) by an elastic ring (3) of partial material by a colonizable material characterized in that the coating  1 "Eye implant comprising at least one core and one covering  the covering (2) consists of an expanded PTFE fabric.  consists of silicone, hydroxyapatite or PMMA 3 Implant according to one of claims 1 or 2, characterized in that  2 "Implant according to claim I, characterized in that the core (1)  coating (2) extends over only part of the core.  4O Implant according to claim 1, characterized in that the  coating (2) extends over the entire surface of the core.  5 implant according to claim 1, characterized in that the