GB2505886A

GB2505886A - Solidifying orbital implant

Info

Publication number: GB2505886A
Application number: GB201216260A
Authority: GB
Inventors: Gianandrea Sciscio
Original assignee: Individual
Current assignee: Individual
Priority date: 2012-09-12
Filing date: 2012-09-12
Publication date: 2014-03-19
Also published as: GB201216260D0

Abstract

An orbital implant for an orbital cavity and a method of forming an orbital implant for an orbital cavity. The orbital implant comprises a solid body (10, Fig 4a) that conforms to at least part of an internal shape of a volume 2 inside the orbital cavity; wherein the solid body 10 has been formed by providing a liquid 8 e.g. by injection, into the volume 2 in the orbital cavity, the liquid being a liquid that will solidify after it is provided to the volume 2 inside the orbital cavity to form the solid body 10, and by allowing the liquid to solidify inside the volume 2 to form the solid body 10 that hence conform to at least a part of the internal shape of the volume 2 in the orbital cavity.

Description

ORBITAL IMPLANT

The invention relates to an orbital implant and a method of forming an orbital implant for an orbital cavity.

S When an eye is blind due to disease or trauma then often a part of the eye or the whole eye is removed. It is known to replace the volume of the removed part of the eye with a sphere which may be made from various materials. These spherical implants come in fixed sizes of 12 to 22 mm in 2 mm graduations. The implant may not be required as a part of a treatment for the patient, but instead it may be used purely for cosmetic purposes in order to give an appearance of a healthy eye.

In known procedures, the eyeball may be eviscerated, such that the eye content is removed but the white wall, the sclera, remains. The evisceration involves removal of the cornea, which leaves a hole of about 11 mm in diameter. In order to maintain the shape of the eye after the evisceration an implant approximately the size of the eye needs to be inserted. Typically the implant is around 20 to 22 mm in adults, and smaller in children depending on their age.

Obviously this will not fit through the hole where the cornea was and as a result the known technique requires the sclera to be cut into two parts so that the implant can be inserted. The sclera is then stitched up around the implant and a false eye' is then put on top of this.

In a first aspect the present invention provides an orbital implant for an orbital cavity, the orbital implant comprising: a solid body that conforms to at least part of an internal shape of a volume inside the orbital cavity; wherein the solid body has been formed by providing a liquid into the volume in the orbital cavity, the liquid being a liquid that will solidify after it is provided to the volume inside the orbital cavity to form the solid body, and by allowing the liquid to solidify inside the volume to form the solid body that hence conforms to at least a part of the internal shape of the volume in the orbital cavity.

The invention extends to a method of forming the orbital eye implant.

Therefore, in a second aspect, the present invention provides a method of forming an orbital implant for an orbital cavity, the method comprising: providing a liquid into a volume inside the orbital cavity, the liquid being a liquid that will solidify after it is provided to the volume inside the orbital cavity to hence form a solid body; and allowing the liquid to solidify within the volume to form the solid body such that it conforms to at least part of the internal shape of the volume.

It is desirable to be able to tailor implants to the individual user and to minimise damage to any remaining parts of the eye when providing an implant.

S By using an orbital implant that has been formed from a liquid provided in a volume in the orbital cavity the solid body that forms the eye implant is moulded inside of the subject's orbital cavity such that it can be tailored to the shape and size of orbital cavity of the subject. This allows the implant to be more comfortable for the user than conventional spherical implants. The implant is moulded within the volume and may conform closely or exactly to the shape of all or a part of the volume in the orbital cavity. The implant can advantageously provide a much better fit to the subject's orbital cavity than prior art spherical implants, both in shape and also in size/volume.

Another advantage of this procedure is that extrusion of the orbital implant can be minimised or prevented.

With current techniques, and particularly certain implants made from porous materials, a slow protrusion of the implant out of the sclera and through the conjunctiva can occur. This can occur in as many as 5% of cases and results in the need for further procedures to correct the defect. This effect is known as extrusion.

With the present method and implant the intact anterior scleral rim, of around 11 mm, can act as a barrier for the forward movement of the orbital implant which will have a far greater diameter and thus prevent extrusion.

The method of forming the orbital implant of the first aspect and the method of the second aspect is not necessarily used as a part of a treatment for maintaining or restoring the health, the physical integrity and the physical well being of a human being or an animal or to prevent diseases. Thus the method may be an entirely cosmetic treatment. In this case the method is not directed to maintaining the life and health of the body on which it is performed and it is not a curative treatment.

When the eye is ineffective due to trauma or disease and it is decided to replace it with an implant, the eyeball can either be eviscerated, in which the eye's content is removed, leaving the scleral shell and extraocular muscles intact, or enucleated, in which the eyeball is removed, but the adjacent structures of the eye socket and eyelids remain. In either of these cases the subject may want an implant to replace the parts of the eye which have been removed. Additionally, a subject who has already had their eye removed may want an implant. It should be noted that the current method would not be applicable in the case of an exenteration in which all the tissues that fill up the bony cavity are removed.

An orbital cavity is the cavity made up of bony walls and soft tissues, such as muscles, nerves and vessels, in which an eyeball is located. When the eyeball S is removed (enucleated) this leaves the orbital cavity empty. When the eye is eviscerated this leaves the white eye wall (the sclera) inside the orbital cavity and leaves an empty cavity inside the eyeball, known as an eye cavity.

The step of providing the liquid into the volume preferably comprises injection of the liquid, for example via an injector with a needle or suitable tubing extending toward and/or into the volume. By knowing the volume of liquid that has been provided to the volume in the orbital cavity it is possible to approximately determine the diameter of a spherical solid body that will be created inside the volume.

In the case when the eye is eviscerated the volume inside the orbital cavity into which the liquid is injected may be the sclera itself. The volume in the sclera may be provided with the liquid to be solidified such that the sclera is partially or completely filled up. Once the liquid has solidified it forms the solid body that hence takes up, partially or completely, the volume within the inside of the sclera. The liquid is preferably directly provided into the sclera, i.e. without any intermediate scaffold or liner. Advantageously the solid body of the implant conforms to the internal shape and size of the sclera.

When the sclera is maintained, with the current implant it is possible to provide an implant inside the eyeball to support the shape of the eyeball without having to make substantial incisions to the sclera. The liquid can be provided through a small hole in the sclera and thus cutting the sclera in two, as has been necessary previously with solid implants, is not necessary. This can minimise damage to the eye, scarring and recovery times. For example the normal anatomical relationship of the muscles would also be retained as there would be less trauma to the extra-scleral contents. This is a significant advantage of the implant described herein.

Preferably when the eye is eviscerated the cornea is only cut partially such that it is still attached to pad of the eye ball. For example the cornea may be cut between 1300 and 2100, and preferably about 1 80W, around its circumference. By only partially cutting the cornea, after the liquid has been provided into the inside of the sciera and has been allowed to set the cornea may be reattached to cover the implanted solid body.

Cutting around only between 130° and 210° of the circumference would allow sufficient access to eviscerate the eye and allow the liquid to be set to be S provided to the sclera whilst being sufficiently attached to ensure that it does not come off completely during the evisceration or the provision of the setting liquid.

Cutting about 180° provides a good balance between it still being securely attached so it does not come off during the procedure whilst allowing sufficient room to access the internals of the eye.

The method of forming the implant may comprise partially cutting around the circumference of the cornea so as to maintain the cornea in a partially attached state, eviscerating the eye to leave the sclera and the partially attached cornea, providing the liquid to the eviscerated sclera, reattaching the cornea, closing the conjunctiva over the sclera and cornea and/or providing a false eye.

In the case when the eye is enucleated, the volume inside the orbital cavity may be a scaffold, such as an inflatable balloon, into which the liquid to be solidified is provided. The implant may hence include a scaffold of this type. The method may include providing a scaffold within the orbital cavity. In this case the general size and shape of the moulded implant may be selected based on the shape of the inside of the cavity to ensure a comfortable fit.

It is preferable for the scaffold to be flexible so that it can be inserted into the orbital cavity through a relatively small hole without causing any damage during insertion, e.g. without the need for further incisions. Also, it is preferable for the scaffold to be flexible so that as it is filled it can conform to the shape of the inside of the orbital cavity so that the liquid can set to form a solid body which conformed to the inside shape of the orbital cavity. The scaffold may be a thin walled and preferably flexible and elastic volume.

After the liquid has solidified the scaffold may be removed from the cavity to leave only the solid body in the orbital cavity. The scaffold may be removed by cutting the scaffold and then pulling it out of the orbital cavity. When the scaffold is to be removed it is preferable that the liquid once solidified does not attach to or bond with the scaffold such that it cannot be removed.

The scaffold may be sized to be larger in volume than the orbital cavity being filled by the implant. This means that that when the scaffold is filled with liquid, the volume of liquid which can be provided is determined by the volume of the cavity left after the removal of the eye. As a result the liquid sets to form a solid body which is shaped to match the cavity rather than the scaffold. The solid body will obviously still conform to at least part of the internal shape of the scaffold but this is dictated by the shape of the cavity rather than the shape of the scaffold when S it is fully expanded. This means that a solid body which is tailored to the orbital cavity can be formed to allow the implant to be comfortable.

If the scaffold being filled is smaller than the orbital cavity the shape of the solid body will be dictated by the shape of the scaffold when allowed to expand to its full size. When the volume of the scaffold is approximately the same as the cavity being filled, in some directions the shape of the solid body may be dictated by the internal shape of the cavity and in other directions (where the scaffold can fully expand without contacting the inside of the cavity) the shape of the scaffold will dictate the shape of the solid body.

Optionally the scaffold may be stretchable. Thus it may be formed of a material that is elastically or plastically deformable when it is filled with the liquid.

With this feature the scaffold can stretch under the pressure of the liquid in order to fill the orbital cavity to the required degree and to provide a volume for the liquid that conforms to the internal shape of the orbital cavity. For example, the scaffold may be made from silicone rubber as this material can expand as it is filled and can predetermine the shape of the formed solid body.

With the use of a scaffold it is preferable for the scaffold to confirm to the shape of the orbital cavity and to provide the volume such that it generally fills the orbital cavity. Preferably the solid body conforms to the internal shape of the scaffold when it is filled with the liquid. This shape is advantageously dictated by the internal shape of the orbital cavity.

In view of the above two described alternatives, the invention may provide an orbital implant for an orbital cavity, the orbital implant comprising: a solid body that conforms to at least a part of an internal shape of a volume within an eviscerated sclera or a scaffold provided in the orbital cavity, wherein the solid body has been formed by providing a liquid into the sclera or the scaffold in the orbital cavity, the liquid being a liquid that will solidify after being provided to the sclera or the scaffold to form a solid body, and by allowing the liquid to solidify inside the sclera or the scaffold to form the solid body that hence conforms to at least a part of the internal shape of the sclera or the scaffold.

The invention may also provide a method of forming an orbital implant for an orbital cavity, the method comprising: providing a liquid into a volume within an eviscerated sclera or a scaffold inside the orbital cavity, the liquid being a liquid that will solidify after being provided into the sclera or the scaffold to hence form a solid S body; and allowing the liquid to solidify to form the solid body such that it conforms to at least part of the internal shape of the sclera or scaffold.

The liquid may be any liquid that can harden, set or solidify to form a solid body after it has been provided into the volume in the orbital cavity. By solid body it is meant a non-porous solid material. The solid body should be able to substantially maintain its shape when relatively small forces are applied to the solid body, i.e. it is relatively incompressible material. This means that the solid body should not lose its shape under strain and should not change shape when moved by the eye muscles, which in certain circumstances it is stitched to.

The solid body may be substantially without voids. The solid body is hence not a body formed of foam or any other porous material. The solid body may, however, contain small, minor or unavoidable air bubbles. Preferably, the solid body is light enough to be supported by the muscles in the orbital cavity so that it does not drop down towards the floor of the orbital cavity.

It is preferable that the solid body forms a sphere, or near sphere, so that it may resemble an eyeball. The advantage of the solid body being of spherical form, or near spherical form, is that it can move easily within the soft tissues of the orbit when under the action of the muscles of the eye similar to the movement of an eyeball, i.e. when looking, right, left, up or down. Moreover the spherical shape may help with coupling, through the conjunctiva, to transmit the vector to the artificial eye that is sitting on top of the conjunctiva so that it may appear more realistic in its movement.

The liquid provided may be a liquid that will harden automatically over time after it is provided to the volume or it may start to harden after solidification is activated, e.g. by means of a setting agent. Thus, the liquid may cure at body temperature and/or upon exposure to air, optionally with a curing agent. In a preferred embodiment the liquid is a silicone that hardens. The silicone may set to form a rubber solid body.

The liquid may be provided to the volume by any known method, for example the liquid may be poured into the volume. Preferably the liquid is injected into the volume which means that it can be provided easily and accurately. It is therefore preferable for the liquid to be injectable.

Preferably the transition from liquid to solid is relatively fast, for example it is preferable that the liquid sets or cures within a few minutes. It is preferable for the liquid to solidify (to a sufficient degree to carry out further procedures on the eye) in less than 10 minutes and more preferably less than 5 minutes. It is advantageous for the liquid to set quickly so that the method can be performed relatively quickly.

The liquid being provided should form a solid body which is biocompatible.

Preferably it is a silicone compound. The silicone may consist of a base and a catalyst which are blended in equal parts at the time of use. The silicone may comprise polydimethylsiloxane with vinyl groups and this may be the main component of the silicone. For example, the compound may be polivinilsiloxane silicone as obtainable from LASCOD S.p.A., Italy. Although any medical grade silicones may feasibly be used, or alternatively acrylics. The advantage of medical grade silicones compared to acrylics is that they set much faster thereby allowing the whole method to be performed faster.

Another advantage of using silicone to form the solid body is that it is possible to pass a suture through at least part of the solid body and that this does not cut through or tear the silicone if tightened. It may be necessary to pass a suture through at least part of the solid body when the eye has been enucleated.

This is because the muscles are cut off the eyeball prior to its removal and it is desirable to stitch them back onto the new orbital implant. Moreover, should there be the need to remove the ball it is possible to cut the silicone ball in two halves, or more smaller pieces, with scissors as it is soft enough so that it can be removed with minimal damage to the orbit.

Certain preferred embodiments of the present invention will now be described by way of example only with reference to the accompanying drawings, in which: Figure la shows a cross section of an eye; Figure lb shows the front view of the eye of Figure la; Figure 2 shows an eviscerated eye; Figure 3 shows the eviscerated eye being injected with liquid silicone according to an embodiment of the invention; Figure 4a shows a cross section of an eviscerated eye with an implant according to an embodiment of the invention; Figure 4b shows a front view of the eye of Figure 4a; Figure 5 shows the eye being covered with a false eye; Figure 6 shows an enucleated orbital cavity; Figure 7 shows the enucleated orbital cavity provided with a scaffold; s Figures shows the scaffold about to be injected with silicone; Figure 9 shows the scaffold injected with silicone; Figure 10 shows the scaffold being cut from around the solid body; Figure 11 shows the scaffold being removed from the orbital cavity; and Figure 12 shows the orbital cavity with the solid body and muscles attached to the solid body.

Figures 1 to 5 show a method of forming an orbital implant for an orbital cavity when the eye in the orbital cavity has been eviscerated. The eye 1 comprises a sclera 2, a retina 3, a lens 4, an iris 5, a cornea 6, and a nerve 7. The first stage, as shown in Figures la and b, is to partially cut the cornea 6 around its circumference. In the example shown the cornea is cut 1800 (the dark line 12 shows the position of the incision) so that it is still partially attached to the sclera 2.

The eye is then eviscerated to remove the intraocular contents such as the retina 3, the lens 4, and the iris 5.

A silicone liquid 8 is then injected directly into the sclera 2 until the volume inside the sclera is full. The liquid is then allowed to set within the sclera to form a solid body. This forms an implant comprising a solid body 10 which conforms to the internal shape of the sclera.

The next stage comprises reattaching, by sutures, the detached part of the cornea 6 to the sclera 2 to enclose the solid body formed form the injected silicone liquid.

Finally, the conjunctiva 13 is closed over the sclera and then a false eye 9 is provided. The false eye 9, also commonly known as a glass eye, is usually made of acrylic and is in the form of a thick contact lens which sits over the conjunctiva 13.

Figures 6 to 12 show an alternative method of forming an orbital implant for an orbital cavity when the eyeball has been removed completely (enucleated) from the orbital cavity. First the orbital cavity 20 is enucleated by removing the eyeball but leaving the soft tissues, such as nerves 23, vessels and muscles 21. The eye muscles 21 are cut as close as possible to their attachment point on the eyeball and the eye nerve 23 is cut at its insertion with the eyeball. The eye lids 22 are also left in position. Figure 7 shows a scaffold 24 in the form of an inflatable balloon inserted into the orbital cavity 20 in a deflated condition. The soft tissues, such as the muscles 21 and nerve 23, have been omitted from Figures 7 to 11 for clarity although they are still present within the orbital cavity during the method.

S Liquid silicone 25 is injected into the deflated balloon 24 to inflate it until it fills the inside of the cavity or the balloon is fully inflated (as shown in Figure 9).

The silicone 25 is then allowed to set so that it forms a solid body 26 which conforms to the inside of the balloon 24, the shape of which is either determined by the shape of the orbital cavity or the fully inflated shape. Once the silicone 25 has set to form the solid body 26 the balloon is cut and pulled out of the cavity (as shown in Figures 10 and 11) so that only the solid body remains. The eye muscles 21 are then sutured to the orbital implant 26 and then the conjunctiva 27 is sutured over the top of the orbital implant. A false eye 28 is then put over the formed solid body 26 on the conjunctiva 27.

Claims

CLAIMS: 1. An orbital implant for an orbital cavity, the orbital implant comprising: a solid body that conforms to at least part of an internal shape of a volume S inside the orbital cavity; wherein the solid body has been formed by providing a liquid into the volume in the orbital cavity, the liquid being a liquid that will solidify after it is provided to the volume inside the orbital cavity to form the solid body, and by allowing the liquid to solidify inside the volume to form the solid body that hence conforms to at least a part of the internal shape of the volume in the orbital cavity.
2. The orbital implant of claim 1, wherein the solid body is moulded within and conforms exactly to at least a part of the internal shape of the volume within the orbital cavity.
3. The orbital implant of claim 2, wherein the volume is a sclcra.
4. The orbital implant of claim 3, wherein the liquid is provided directly into the sclera.
5. The orbital implant of claim 1, wherein the volume is a scaffold, such as a balloon.
6. The orbital implant of claim 5, wherein the scaffold is flexible.
7. The orbital implant of claim 5 or 6, wherein the scaffold is sized to have approximately the same volume as the orbital cavity when the scaffold is filled with material.
8. The orbital implant of any preceding claim, wherein the liquid is a biocompatible material.
9. The orbital implant of any preceding claim, wherein the liquid is a silicone compound.
10. A method of forming the orbital implant of any preceding claim.
11. A method of forming an orbital implant for an orbital cavity, the method comprising: providing a liquid into a volume inside the orbital cavity, the liquid being a liquid which will solidify after it is provided to the volume inside the eye to form a solid body; and allowing the liquid to solidify to form the solid body to conform to at least part of the internal shape of the volume to form the solid body.
12. The method of claim 11, wherein the method is a cosmetic treatment.
13. The method of claim 11 or 12, wherein the volume is a sclera.
14. The method of claim 13, wherein the liquid is provided directly to the sclera.
15. The method of claim 11 or 12, wherein the volume is a scaffold.
16. The method of claim 15, wherein the scaffold is flexible.
17. The method of claim 15 or 16, wherein the scaffold is sized to have approximately the same volume as the orbital cavity when the scaffold is filled with material.
18. The method of any one of claims 11 to 17, wherein the liquid is a biocompatible material.
19. The method of any one of claims 11 to 18, wherein the liquid is a silicone compound.
20. The method of any one of claims 11 to 19, wherein the liquid solidifies in less than 10 minutes.
21. An orbital implant for an orbital cavity as substantially hereinbefore described with reference to Figures 1 to 5.
22. A method of forming an orbital implant for an orbital cavity substantially hereinbefore described with reference to Figures 1 to 5.