WO2012061124A1

WO2012061124A1 - Digital keratoconus scleral shell prosthetic eye device

Info

Publication number: WO2012061124A1
Application number: PCT/US2011/057666
Authority: WO
Inventors: Carole Lewis
Original assignee: Carole Lewis
Priority date: 2010-10-25
Filing date: 2011-10-25
Publication date: 2012-05-10

Abstract

A process for making a prosthetic eye device (10) includes the steps of forming an iris substrate (24) and extending a stem (26) away from the iris substrate (24). A scleral shell assembly (34) is molded, the iris substrate (24) being molded together with the scleral shell assembly (34), the stem (26) extending away from the scleral shell assembly (34). An iris member (38) is provided, the iris member (38) generally matching the appearance of the iris of a natural eye, the iris member (38) further including an aperture (42) extending therethrough. The iris member (38) is assembled to the scleral shell assembly (34), the aperture (42) of the iris member (38) engaging the stem (26). A first, generally transparent, plastic layer (44) is applied to the assembled iris member (38) and scleral shell assembly (34), the first plastic layer (44) generally covering the iris member (38).

Description

DIGITAL KERATOCONUS SCLERAL SHELL PROSTHETIC EYE DEVICE

This application claims priority to U.S. patent application 61/406,366, filed October 25, 2010, the contents of which are hereby incorporated by reference.

Field

This invention relates to a prosthetic eye device, more particularly to a relatively thin prosthetic eye device fitting over an existing "live" eye or globe and having an appearance matching that of a natural eye. The prosthetic eye may be produced in a manner that is both time and cost efficient.

Background

Prosthetic eye devices are known in the art and can be configured to partially or completely replace an eye, such as a human eye, for the aesthetic purpose of providing a more normal appearance. People may require use of such a prosthetic eye device arising from a variety of reasons, such as an accident, disease or birth defect. Thus, the type of prosthetic eye device that is used can, and will, vary in its design, depending upon the particular application. In the case where a frontside portion of the eye is being replaced, or a case where a frontside portion of the eye is being complemented, the prosthetic eye device may include an iris portion that is constructed to replicate the appearance of the iris of the patient's existing eye. The iris portion of the device preferably comprises a complex colored and patterned portion that extends concentrically around the pupil portion of the eye to the sclera or white portion of the eye.

Prosthetic eye devices are conventionally made from materials such as plastic and comprise an iris image positioned at a frontside portion of a scleral shell device that is intended to replicate the color and patterning of a natural eye. Typically, the iris image is painted on the frontside portion of the eye device. A drawback of a painted iris is that it typically lacks the appearance of depth found in a natural eye. In addition, such devices lack a limbal blend or transition between the iris and sclera portions. Consequently, the iris has a decal-like appearance, further reducing the realistic look of the eye device.

In an attempt to overcome these drawbacks, a pre-formed plastic element was developed. The iris element has an image disposed upon a curved surface, the image depicting the color and patterning of a normal eye. However, the iris element is not tailored to a particular eye of a particular patient. Consequently, the resulting eye device does not properly and/or comfortably fit the eyes of all patients. Another disadvantage of current prosthetic eye devices is that they must be relatively thick in order to achieve a relatively realistic appearance. This is due in part to the fact that most ocularists utilize various surface paints on the scleral shell to provide eye features such as the iris, pupil and veins. The resulting build-up of painted layers, if relatively thick, can cause discomfort to the wearer since it adds a layer over an underlying eye.

Yet another disadvantage of current eye devices is that a backside surface of the eye device is not fitted to the globe of a particular patient's eye. As a result, the eye device does not always precisely interface with the eye, particularly in the case of an eye having an irregular or damaged surface. This can cause discomfort to the wearer of the eye device.

Still another shortcoming of current eye devices is that the aforementioned fit and thickness issues can cause a mismatch between the open position of the eyelid of the damaged eye and the eyelid of an undamaged companion eye. This further reduces the natural appearance of the prosthetic eye device. Accordingly, there is a need for a prosthetic eye device that is comfortably thin while presenting a realistic appearance.

Summary

A prosthetic eye device is disclosed according to an embodiment of the present invention. A backside surface of the eye device is precisely fitted to the surface of the eye of a particular patient and is reducable in size and contour as need to fit the patient. The eye device thus better fits the eye of the wearer. This is particularly important in the case of a "live" eye, which is sensitive to physical contact. The thickness of the eye device is also reducable to achieve the proper opening of the eyelid of the damaged eye with respect to the eyelid of an undamaged companion eye. The resulting prosthetic eye device is relatively thin and comfortable to wear, yet includes realistic features and apparent depth closely matching that of the wearer's uninjured eye.

One aspect of the present invention is a process for making a prosthetic eye device. The process includes the steps of forming an iris substrate and extending a stem away from the iris substrate. A scleral shell assembly is molded, the iris substrate being molded together with the scleral shell assembly, the stem extending away from the scleral shell assembly. An iris member is provided, the iris member generally matching the appearance of the iris of a natural eye, the iris member further including an aperture extending therethrough. The iris member is assembled to the scleral shell assembly, the aperture of the iris member engaging the stem. A first, generally transparent, plastic layer is applied to the assembled iris member and scleral shell assembly, the first plastic layer generally covering the iris member.

Another aspect of the present invention is a prosthetic eye device. The prosthetic eye device includes an iris substrate. A stem extends away from the iris substrate. The prosthetic eye device further includes a scleral shell assembly, the iris substrate being joined to the scleral shell assembly, the stem extending away from the scleral shell assembly. An iris member is assembled to the scleral shell assembly, the iris member generally matching the appearance of the iris of a natural eye, the iris member further including an aperture extending therethrough. The iris member is assembled to the scleral shell assembly such that the aperture of the iris member engages the stem. A first, generally transparent, plastic layer is disposed upon the assembled iris member and scleral shell assembly, the first plastic layer generally covering the iris member.

Brief Description of the Drawings

Further features of the inventive embodiments will become apparent to those skilled in the art to which the embodiments relate from reading the specification and claims with reference to the accompanying drawings, in which:

Fig. 1 is a flow diagram of a process for making a prosthetic eye device according to an embodiment of the present invention;

Fig. 2A is a top plan view of a front surface of a test template according to an embodiment of the present invention;

Fig. 2B is a view in section of the test template of Fig. 2 A;

Fig. 3 is a is a side elevational view of a pressing device used to shape the test template of Figs. 2A and 2B according to an embodiment of the present invention;

Fig. 4A is a top plan view of a front surface of a test template with a protrusion attached thereto according to an embodiment of the present invention;

Fig. 4B is a view in section of the test template of Fig. 4 A;

Fig. 5 is a side elevational view of a pressing device used to shape an iris substrate according to an embodiment of the present invention;

Fig. 6A is a top plan view of a front surface of an iris substrate before shaping, according to an embodiment of the present invention; Fig. 6B is a view in section of the iris substrate of Fig. 6A;

Fig. 7 is a side elevational view of the iris substrate of Figs. 6A and 6B after shaping;

Fig. 8 is a is a side elevational view of a pressing device used to shape a scleral shell assembly according to an embodiment of the present invention;

Fig. 9 is a top plan view of a scleral shell assembly formed by the pressing device of Fig. 8;

Fig. 10 is a top plan view of an iris member according to an embodiment of the present invention;

Fig. 11 is a top plan view of a prosthetic eye device according to an embodiment of the present invention; and

Fig. 12 is a partial view in section of the prosthetic eye device of Fig. 9.

Detailed Description

In the discussion that follows, like reference numerals are used to represent elements of like structure and function in the various figures.

A process si 00 for fabricating a prosthetic eye device 10 is shown in Fig. 1 according to an embodiment of the present invention. At step si 02 a negative mold of a damaged socket or globe (hereafter generally termed "injured eye") of a patient is made from an impression using conventional casting materials including, without limitation, wax and alginate materials. The casting material is urged against the injured eye such that it substantially conforms to the geometry of the tissues and/or any ocular implants therein. After the casting material has cured it is removed.

At step si 04 a positive model is made of the negative mold. This is accomplished by preparing a conventional casting material such as "dental stone" casting cement. The casting material is poured into the negative mold and is allowed to cure, after which the negative mold is separated, leaving a positive model that duplicates the geometry of the patient's injured eye.

At step si 06 a test template 12 (Fig. 2) is made from the positive model of step si 04 in any suitable manner. With reference to Fig. 3, in a preferred embodiment test template 12 may be formed from a plastic mixture 14 of methyl methacrylic monomer and polymer such as polymethyl methacrylate (PMMA). Mixture 14 preferably has the general consistency of modeling clay, said mixture being placed into a two-piece flask fixture 200, each piece of the flask having an impression configured to correspond and register with one another and having opposing surface features consisting of a positive model 202 of the patient's injured eye and a negative model 204 generally corresponding to the size, shape and geometry of an uninjured eye. A clamp 206 is operated by turning a threaded member 208 to press together a pair of press members 210, 212 having the negative model 204 and the positive model 202 respectively attached thereto. The resulting pressure causes mixture 14 to conform to a shape controlled by positive model 202 and negative model 204. The formed test template 12 is subjected to heat under said pressure until it is cured and hardened. A rear surface 16 of test template 12 conforms to positive model 202, while a front surface 18 of the test template conforms to negative model 204.

In an alternate embodiment of the present invention a test template 12 may be formed at step si 06 by pressing a heat-softened sheet of plastic material, such as acrylic, over the positive model of step si 04.

At step si 08 edges 20 and front surface 18 of the test template 12 are smoothed and the entire test template is polished before inserting it in under the eyelid of a patient. The test template 12 is fitted to the patient to ensure a proper and comfortable fit, and may be removed and altered as needed to accomplish this aim. Test template 12 may optionally be made of a substantially transparent material to allow an ocularist to better observe how its contours (i.e., rear surface 16, front surface 18 and edges 20) conform to the geometry of the patient's eye. If necessary, the positive and/or negative models 202, 204 may be modified and/or replaced by new, recast models and additional test templates 12 may be made therefrom as needed to obtain an acceptable fit.

With continued reference to Fig. 2 A, after the test template 12 has been adjusted such that it provides a proper fit at step si 08 the finished test template is marked at step si 10 with an ink, paint or etched locator mark 22 to indicate the proper location of a prosthetic pupil. Particular care is preferably taken to ensure that the location of locator mark 22 is consistent with the patient's undamaged or natural eye (hereafter generally termed "natural eye"). Preferably, the proper location represents the location of the primary gaze of the patient's natural eye.

An iris substrate is molded at step si 12. A protrusion 25 is attached to front surface 18 of test template 12 at locator mark 22 with wax or other suitable adhesive, as shown in Figs. 4 A and 4B. A base 27 of protrusion 25 may optionally be notched to provide a larger adhering surface for the protrusion when attaching the protrusion to test template 12. A pair of complementary press members 205, 207 (Fig. 5) are then formed in the shape and contours of the finished test template 12 with protrusion 25 joined thereto, using the finished test template as a model. At step si 14 press members 205, 207 are then utilized in conjunction with flask fixture 200 (Fig. 5) to form iris substrate 24 utilizing a plastic material 29 comprising, for example, methyl methacrylic monomer and polymer such as polymethyl methacrylate (PMMA). In one embodiment molding material 29 may be a predetermined color, such as black. The resulting iris substrate 24 replicates the shape and contours of test template 12, particularly rear surface 16, front surface 18 and edges 20, with an integral stem 26 extending generally away from the iris substrate as shown in Figs. 6 A and 6B.

At step si 16 iris substrate 24 is shaped. During this step the portion of iris substrate 24 corresponding to the iris area of the patient's eye is identified. Any extraneous material is removed by an abrasive removal process, such as a dental grinding lathe. Other processes such as, for example, die cutting and heated forms, are also usable. The resultant shaped iris substrate 24 has a substantially circular periphery with a diameter sized to substantially match the iris of the patient's natural eye, as generally shown in Fig. 7. A front surface 28 of iris substrate corresponds to front surface 18 of test template 12, while a rear surface 30 of the iris substrate corresponds to rear surface 16 of the test template.

At step si 18, and with reference to Figs. 8 and 9, flask 200 is used to mold iris substrate 24 and stem 26 together with a generally white-colored plastic material 32 comprising, for example, methyl methacrylic monomer and polymer such as polymethyl methacrylate (PMMA) to form a scleral shell assembly 34. Clamp 206 is operated by turning threaded member 208 to press together the two press members 210, 212 and, in turn, iris substrate 24 and scleral shell molding material 32. The resulting pressure causes scleral shell molding material 32 to conform to a shape controlled by a positive model 214 and a negative model 216 conforming to the shape of positive model 202 and negative model 204 respectively of the finished test template 12. Negative model 216 further includes a cavity 218 sized and shaped to accommodate iris substrate 24. An opening 220 is provided in negative model 216 and, optionally, press member 210, to accommodate stem 26 in flask 200. A scleral shell assembly 34 formed thereby is subjected to heat under said pressure until it is cured and hardened, front surface 28 and stem 26 of iris substrate 24 being oriented away from a frontside or outer surface 36 of the scleral shell assembly, as shown in Figs. 9 and 12. Any excess scleral molding material formed over front surface 28 of iris substrate 24 during the formation of scleral shell assembly 24 may be removed during this step, as well.

With reference to Figs. 10 and 12, at step si 20 an iris member 38 is formed.

Preferably, iris member 38 closely matches the size and shape of the iris of the patient's natural eye. Iris member 38 further preferably includes a front surface 40 having a color (or colors), patterning, flecking, hue, and other such distinguishing features of the iris of the patient's natural eye. Exemplary processes for making an iris member are described in the inventor's U.S. Patent Nos. 7,291,294 and 7,029,608, the entire contents of each being incorporated herein by reference thereto. However, any process now known or later developed may be utilized to form iris member 38. After iris member 38 is formed, a pupil portion is removed by any suitable means, such as with a knife or a punch, leaving an aperture 42.

A portion of the length of stem 26 may be removed as desired at step si 22, leaving a stub as an orientation member. Iris member 38 is assembled to front surface 28 of iris substrate 24, front surface 40 of the iris member facing away from the front surface of the iris substrate. If needed, front surface 28 of iris substrate 24 may be shaped, such as slightly flattening the front surface to more precisely receive iris member 38. In the assembled condition stem 26 extends through aperture 42 of iris member 38 and away from the frontside surface 36 as shown in Fig. 12. Iris member 38 may be secured to scleral shell assembly 34 with a suitable adhesive (not shown) if desired. Stem 26 is further truncated so that a distal end of the stem is generally level with iris member 38. As seen best in Figs. 9 and 12, stem 26 in this form acts as a prosthetic pupil.

At step si 24 a first generally transparent plastic layer 44 is applied to one or more of frontside surface 36 of scleral shell assembly 34, iris substrate 24 and iris member 38, the plastic layer generally covering the iris member and laminating the iris member to the scleral shell assembly. First plastic layer 44 may be made from any suitable material such as, but not limited to, acrylic such as, a mixture of methyl methacrylic monomer and polymer such as polymethyl methacrylate (PMMA) and may be provided in any suitable form including, without limitation, liquids, resins and gels. With reference to Fig. 12, a sclera layer 46 may be applied to frontside surface 36 of scleral shell assembly 34 at step sl26. Sclera layer 46 may be made from any suitable material, including scleral molding material 32. Sclera layer 46 is preferably shaped to form a limbal transition or "blend" 48 proximate iris member 38. Limbal transition may be made in any suitable manner including, but not limited to, selectively removing portions of sclera layer 46 with an abrasive grinding process.

Individual features 50, shown in Fig. 11, are added to scleral shell assembly 34, atop sclera layer 46, at step si 28. These features may include, but are not limited to, simulated veins and tinting. Simulated veins may be formed by any suitable process, such as with thread and paint. Similarly, sclera shell assembly 34 may be tinted with any suitable paint such as, for example, acrylic paint to match the sclera of the patient's natural eye.

With reference to Figs. 11 and 12, at step sl30 a second, generally transparent plastic layer 52 is applied to one or more of first plastic layer 44, sclera layer 46 and individual features 50. Second plastic layer 52 may be made from any suitable material such as, but not limited to, acrylic such as a mixture 14 of methyl methacrylic monomer and polymer such as polymethyl methacrylate (PMMA), and may be provided in any suitable form including, without limitation, liquids, resins and gels.

Finally, at step si 32 second plastic layer 52 is buffed and/or polished to a high shine. Buffing and/or polishing may be accomplished by hand and/or using powered polishing wheels.

While this invention has been shown and described with respect to a detailed embodiment thereof, it will be understood by those skilled in the art that changes in form and detail thereof may be made without departing from the scope of the claims of the invention. For example, any suitable plastic and/or composite materials including, but not limited to, polycarbonate may be selected for the various components of eye device 10 within the scope of the invention.

Claims

Claims What is claimed is:

1. A method for making a prosthetic eye device, comprising the steps of:

forming an iris substrate;

extending a stem away from the iris substrate;

molding a scleral shell assembly, the iris substrate being molded together with the scleral shell assembly, the stem extending away from the scleral shell assembly;

providing an iris member, the iris member generally matching the appearance of the iris of a natural eye, the iris member further including an aperture extending therethrough;

assembling the iris member to the scleral shell assembly, the aperture of the iris member engaging the stem; and

applying a first, generally transparent, plastic layer to the assembled iris member and scleral shell assembly, the first plastic layer generally covering the iris member.

2. The method of claim 1 wherein the stem is a separate piece, the stem being attached to the iris substrate.

3. The method of claim 1 wherein the stem is integral to the iris substrate.

4. The method of claim 1, further including the step of trimming the stem generally level with the iris member.

5. The method of claim 1, further including the step of fabricating a test template, the test template being fitted to an injured eye of a patient, the iris substrate being formed in a shape consistent with the test template.

6. The method of claim 5, further including the step of selecting a generally transparent material for the test template.

7. The method of claim 5, further including the steps of: marking a locator mark upon the test template; and

extending the stem of the iris substrate from a location of the iris substrate generally corresponding to the location of the locator mark of the test template.

8. The method of claim 1, further including the step of shaping the iris substrate, the shaped iris substrate having a substantially circular periphery with a diameter sized to substantially match the iris of a natural eye.

9. The method of claim 5, further including the steps of:

making an impression of the injured eye of the patient;

fabricating a negative mold from the impression;

fabricating a positive model from the negative mold; and

forming the shape of the test template with the positive model.

10. The method of claim 1, further including the step of generally covering the first plastic layer with a sclera layer.

11. The method of claim 10, further including the step of shaping the sclera layer to form a limbal transition proximate the iris member.

12. The method of claim 10, further including the step of applying individual features to the scleral shell assembly.

13. The method of claim 12, wherein the individual features include at least one of simulated veins and tinting to match a natural eye.

14. The method of claim 10, further including the step of generally covering the sclera layer with a second generally transparent, plastic layer.

15. The method of claim 14, further including the step of polishing the second plastic layer.

16. The method of claim 1, wherein the iris member closely matches at least one of the size, shape and color of a natural eye.

17. A method for making a prosthetic eye device, comprising the steps of:

fabricating a test template, the test template being fitted to an injured eye of a patient;

marking a locator mark upon the test template;

forming an iris substrate, the iris substrate being formed in a shape consistent with the test template;

extending a stem away from a location of the iris substrate generally corresponding to the location of the locator mark of the test template;

shaping the iris substrate, the shaped iris substrate having a substantially circular periphery with a diameter sized to substantially match the iris of a natural eye;

18. The method of claim 17, further including the steps of:

generally covering the first plastic layer with a sclera layer; and

shaping the sclera layer to form a limbal transition proximate the iris member.

19. The method of claim 18, further including the step of applying individual features to the scleral shell assembly.

20. A prosthetic eye device, comprising:

an iris substrate; a stem extending away from the iris substrate;

a scleral shell assembly, the iris substrate being joined to the scleral shell assembly, the stem extending away from the scleral shell assembly;

an iris member, the iris member generally matching the appearance of the iris of a natural eye, the iris member further including an aperture extending therethrough, the iris member being assembled to the scleral shell assembly such that the aperture of the iris member engages the stem; and

a first, generally transparent, plastic layer disposed upon the assembled iris member and scleral shell assembly, the first plastic layer generally covering the iris member.