Ocular Implant Architectures
An ocular implant having a first spine; a second spine; a first strut extending in an axial direction Z between the first spine and the second spine; a second strut extending in an axial direction Z between the first spine and the second spine; wherein an angular dimension θ of a first edge of each strut undulates as the strut extends in the axial direction Z between the first spine and the second spine; and wherein a radius r of an outer surface of each strut remains substantially constant as the strut extends the axial direction Z between the first spine and the second spine.
This application is a continuation-in-part of U.S. application Ser. No. 11/860,318, filed Sep. 24, 2007, and claims priority to U.S. Provisional Application No. 61/033,746, filed Mar. 4, 2008, the disclosures of which are incorporated by reference as if fully set forth herein.
INCORPORATION BY REFERENCEAll publications and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference.
FIELD OF THE INVENTIONThe present invention relates generally to devices that are implanted within the eye. More particularly, the present invention relates to devices that facilitate the transfer of fluid from within one area of the eye to another area of the eye.
BACKGROUND OF THE INVENTIONAccording to a draft report by The National Eye Institute (NEI) at The United States National Institutes of Health (NIH), glaucoma is now the leading cause of irreversible blindness worldwide and the second leading cause of blindness, behind cataract, in the world. Thus, the NEI draft report concludes, “it is critical that significant emphasis and resources continue to be devoted to determining the pathophysiology and management of this disease.” Glaucoma researchers have found a strong correlation between high intraocular pressure and glaucoma. For this reason, eye care professionals routinely screen patients for glaucoma by measuring intraocular pressure using a device known as a tonometer. Many modern tonometers make this measurement by blowing a sudden puff of air against the outer surface of the eye.
The eye can be conceptualized as a ball filled with fluid. There are two types of fluid inside the eye. The cavity behind the lens is filled with a viscous fluid known as vitreous humor. The cavities in front of the lens are filled with a fluid know as aqueous humor. Whenever a person views an object, he or she is viewing that object through both the vitreous humor and the aqueous humor.
Whenever a person views an object, he or she is also viewing that object through the cornea and the lens of the eye. In order to be transparent, the cornea and the lens can include no blood vessels. Accordingly, no blood flows through the cornea and the lens to provide nutrition to these tissues and to remove wastes from these tissues. Instead, these functions are performed by the aqueous humor. A continuous flow of aqueous humor through the eye provides nutrition to portions of the eye (e.g., the cornea and the lens) that have no blood vessels. This flow of aqueous humor also removes waste from these tissues.
Aqueous humor is produced by an organ known as the ciliary body. The ciliary body includes epithelial cells that continuously secrete aqueous humor. In a healthy eye, a stream of aqueous humor flows out of the anterior chamber of the eye through the trabecular meshwork and into Schlemm's canal as new aqueous humor is secreted by the epithelial cells of the ciliary body. This excess aqueous humor enters the venous blood stream from Schlemm's canal and is carried along with the venous blood leaving the eye.
When the natural drainage mechanisms of the eye stop functioning properly, the pressure inside the eye begins to rise. Researchers have theorized prolonged exposure to high intraocular pressure causes damage to the optic nerve that transmits sensory information from the eye to the brain. This damage to the optic nerve results in loss of peripheral vision. As glaucoma progresses, more and more of the visual field is lost until the patient is completely blind.
In addition to drug treatments, a variety of surgical treatments for glaucoma have been performed. For example, shunts were implanted to direct aqueous humor from the anterior chamber to the extraocular vein (Lee and Scheppens, “Aqueous-venous shunt and intraocular pressure,” Investigative Opthalmology (February 1966)). Other early glaucoma treatment implants led from the anterior chamber to a sub-conjunctival bleb (e.g., U.S. Pat. No. 4,968,296 and U.S. Pat. No. 5,180,362). Still others were shunts leading from the anterior chamber to a point just inside Schlemm's canal (Spiegel et al., “Schlemm's canal implant: a new method to lower intraocular pressure in patients with POAG?” Ophthalmic Surgery and Lasers (June 1999); U.S. Pat. No. 6,450,984; U.S. Pat. No. 6,450,984).
SUMMARY OF THE INVENTIONOne aspect of the invention provides an ocular implant having a first spine; a second spine; a first strut extending in an axial direction Z between the first spine and the second spine; a second strut extending in an axial direction Z between the first spine and the second spine; wherein an angular dimension θ of a first edge of each strut undulates as the strut extends in the axial direction Z between the first spine and the second spine; and wherein a radius r of an outer surface of each strut remains substantially constant as the strut extends the axial direction Z between the first spine and the second spine.
Yet another aspect of the invention provides an ocular implant having a first spine section; a second spine section; and a first frame extending between the first spine section and the second spine section, the frame having a diameter of between 0.005 inches and 0.04 inches, the ocular implant being adapted to be disposed within a canal of Schlemm in a human eye.
In some embodiments, the first spine section, the second spine section, and the first frame form portions of a single tubular wall. Each spine section may optionally have only a single spine. In some embodiments, each spine section has an arcuate shape in lateral cross section. In some embodiments, the first spine has a first circumferential extent and the first frame has a second circumferential extent, wherein the second circumferential extent is greater than the first circumferential extent.
In some embodiments, the first frame has a first strut and a second strut and may have only two struts. Each strut may optionally have an arcuate shape in lateral cross section.
In embodiments in which the first strut has a first edge (partially defining, e.g., a first opening in the ocular implant), an angular dimension θ of the first edge may undulate as the strut extends in an axial direction Z between the first spine and the second spine. An angular dimension θ of the first edge may also first increase, then decrease, as the strut extends in an axial direction Z between the first spine and the second spine. Also, a radius r of the first edge may remain substantially constant as the strut extends in axial dimension Z between the first spine and the second spine.
In some embodiments, the first strut has a thickness that is substantially constant in a radial direction. In some embodiments, the first strut has a width extending in an arc along a circumferential direction. In some embodiments, the first strut has a length extending in an axial direction that is generally parallel to a longitudinal axis of the ocular implant.
The first spine section and the second spine section may be axially aligned with one another. A shape of the second strut may also be a mirror image of a shape of the first strut.
Some embodiments of the ocular implant have a second frame extending between the second spine and a third spine. Some embodiments of the ocular implant have a first opening extending between the first edge of the first strut and the first edge of the second strut. In some embodiments, a second edge of the first strut and a second edge of the second strut defining a second opening. In some embodiments, the first strut, the second strut, the first spine section, and the second spine section all define a cylindrical volume.
Some embodiments of the ocular implant have a therapeutic agent (e.g., an anti-glaucoma drug such as a prostaglandin analog like latanprost) deposited on the frame and spine sections.
Still another aspect of the invention provides an ocular implant having a first spine; a second spine; a first frame comprising a first strut and a second strut; each strut extending in an axial direction Z between the first spine and the second spine; a first opening of the ocular implant extending between a first edge of the first strut and a first edge of the second strut; a second edge of the first strut and a second edge of the second strut defining a second opening; wherein an angular dimension θ of the first edge of each strut undulates as the strut extends in the axial direction Z between the first spine and the second spine; and wherein a radius r of an outer surface of each strut remains substantially constant as the strut extends the axial direction Z between the first spine and the second spine.
The following detailed description should be read with reference to the drawings, in which like elements in different drawings are numbered identically. The drawings, which are not necessarily to scale, depict exemplary embodiments and are not intended to limit the scope of the invention. Examples of constructions, materials, dimensions, and manufacturing processes are provided for selected elements. All other elements employ that which is known to those of skill in the field of the invention. Those skilled in the art will recognize that many of the examples provided have suitable alternatives that can be utilized.
First strut 120 of first frame 106 comprises a first edge 124A and a second edge 126A. With reference to
With continuing reference to
Elongate channel 142 of ocular implant 136 fluidly communicates with a first opening 128 as well as inlet portion 101. Various fabrication techniques may be used to fabricate ocular implant 136. For example, ocular implant 136 can be fabricated by providing a generally flat sheet of material and laser cutting the sheet of material to form body 100 shown in
As shown in
First strut 120 of first frame 106 comprises a first edge 124A and a second edge 126A. Second strut 122 has a shape that is a mirror image of the shape of first strut 120. In
Ocular implant 136 can be fabricated from various biocompatible materials possessing the necessary structural and mechanical attributes. Both metallic and non-metallic materials may be suitable. Examples of metallic materials include stainless steel, tantalum, gold, titanium, and nickel-titanium alloys known in the art as Nitinol. Nitinol is commercially available from Memry Technologies (Brookfield, Conn.), TiNi Alloy Company (San Leandro, Calif.), and Shape Memory Applications (Sunnyvale, Calif.).
Ocular implant 136 may include one or more therapeutic agents. One or more therapeutic agents may, for example, be incorporated into a polymeric coating that is deposited onto the outer surfaces of the struts and spines of the ocular implant. The therapeutic agent may comprise, for example, an anti-glaucoma drug. Examples of anti-glaucoma drugs include prostaglandin analogs. Examples of prostaglandin analogs include latanprost.
As shown in
Ocular implant 236 of
In the embodiment of
In the embodiment of
In
In the embodiment of
Ocular implant 236 may be used in conjunction with a method of treating a patient. Some such methods may include the step of inserting a core member into a lumen defined by ocular implant 236. The core member may comprise, for example, a wire or tube. The distal end of the ocular implant may be inserted into Schlemm's canal. The ocular implant and the core member may then be advanced into Schlemm's canal until the ocular implant has reached a desired position. The core member may then be withdrawn from the ocular implant.
Whenever a person views an object, he or she is viewing that object through the cornea, the aqueous humor, and the lens of the eye. In order to be transparent, the cornea and the lens can include no blood vessels. Accordingly, no blood flows through the cornea and the lens to provide nutrition to these tissues and to remove wastes from these tissues. Instead, these functions are performed by the aqueous humor. A continuous flow of aqueous humor through the eye provides nutrition to portions of the eye (e.g., the cornea and the lens) that have no blood vessels. This flow of aqueous humor also removes waste from these tissues.
Aqueous humor is produced by an organ known as the ciliary body. The ciliary body includes epithelial cells that continuously secrete aqueous humor. In a healthy eye, a stream of aqueous humor flows out of the eye as new aqueous humor is secreted by the epithelial cells of the ciliary body. This excess aqueous humor enters the blood stream and is carried away by venous blood leaving the eye.
The structures that drain aqueous humor from the anterior chamber include Schlemm's canal and a large number of veins that communicate with Schlemm's canal via a plurality of outlets. In
In
Aqueous humor exits Schlemm's canal 20 by flowing through a number of outlets. After leaving Schlemm's canal 20, aqueous humor travels through a network passages and veins and is absorbed into the blood stream. Schlemm's canal typically has a non-circular cross-sectional shape whose diameter can vary along the canal's length and according to the angle at which the diameter is measured. In addition, there may be multiple partial pockets or partial compartments (not shown in these figures) formed along the length of Schlemm's canal. The shape and diameter of portions of Schlemm's canal and the existence and relative location of partial pockets or compartments may limit or prevent fluid flow from one point of Schlemm's canal to another. Hence, each outlet from Schlemm's canal may drain only a portion of Schlemm's canal. This condition may be improved by placing ocular implant 236 in Schlemm's canal. Ocular implant 236 shown in
In
While exemplary embodiments of the present invention have been shown and described, modifications may be made, and it is therefore intended in the appended claims to cover all such changes and modifications which fall within the true spirit and scope of the invention.
Claims
1. An ocular implant, comprising:
- a first spine;
- a second spine;
- a first strut extending in an axial direction Z between the first spine and the second spine;
- a second strut extending in an axial direction Z between the first spine and the second spine;
- wherein an angular dimension θ of a first edge of each strut undulates as the strut extends in the axial direction Z between the first spine and the second spine; and
- wherein a radius r of an outer surface of each strut remains substantially constant as the strut extends the axial direction Z between the first spine and the second spine.
2. An ocular implant, comprising:
- a first spine section;
- a second spine section;
- a first frame extending between the first spine section and the second spine section, the frame having a diameter of between 0.005 inches and 0.04 inches;
- the ocular implant being adapted to be disposed within a canal of Schlemm in a human subject's eye.
3. The ocular implant of claim 2, wherein the first spine section, the second spine section, and the first frame comprise portions of a single tubular wall.
4. The ocular implant of claim 2, wherein each spine section comprises only a single spine.
5. The ocular implant of claim 2, wherein each spine section has an arcuate shape in lateral cross section.
6. The ocular implant of claim 2, wherein:
- the first spine has a first circumferential extent; and
- the first frame has a second circumferential extent;
- wherein the second circumferential extent is greater than the first circumferential extent.
7. The ocular implant of claim 2, wherein the first frame comprises a first strut and a second strut.
8. The ocular implant of claim 7, wherein the first frame comprises only two struts.
9. The ocular implant of claim 7, wherein each strut has an arcuate shape in lateral cross section.
10. The ocular implant of claim 7, wherein the first strut comprises a first edge.
11. The ocular implant of claim 10, wherein an angular dimension θ of the first edge undulates as the strut extends in an axial direction Z between the first spine and the second spine.
12. The ocular implant of claim 10, wherein an angular dimension θ of the first edge first increases, then decreases, as the strut extends in an axial direction Z between the first spine and the second spine.
13. The ocular implant of claim 10, wherein a radius r of the first edge remains substantially constant as the strut extends in axial dimension Z between the first spine and the second spine.
14. The ocular implant of claim 10, wherein the first edge partially defines a first opening in the ocular implant.
15. The ocular implant of claim 7, wherein the first strut has a thickness that is substantially constant in a radial direction.
16. The ocular implant of claim 7, wherein the first strut has a width extending in an arc along a circumferential direction.
17. The ocular implant of claim 7, wherein the first strut has a length extending in an axial direction that is generally parallel to a longitudinal axis of the ocular implant.
18. The ocular implant of claim 7, wherein the first spine section and the second spine section are axially aligned with one another.
19. The ocular implant of claim 7, wherein a shape of the second strut is a mirror image of a shape of the first strut.
20. The ocular implant of claim 7, further comprising a second frame extending between the second spine and a third spine.
21. The ocular implant of claim 7, wherein a second edge of the first strut and a second edge of the second strut defining a second opening.
22. The ocular implant of claim 7, wherein the first strut, the second strut, the first spine section, and the second spine section all define a cylindrical volume.
23. The ocular implant of claim 7, further comprising a first opening extending between the first edge of the first strut and the first edge of the second strut.
24. The implant of claim 2 further comprising a therapeutic agent deposited on the frame and spine sections.
25. The implant of claim 24 wherein the therapeutic agent comprises an anti-glaucoma drug.
26. The implant of claim 25 wherein the anti-glaucoma drug comprises a prostaglandin analog.
27. The implant of claim 26 wherein the prostaglandin analog comprises latanprost.
28. An ocular implant, comprising:
- a first spine;
- a second spine;
- a first frame comprising a first strut and a second strut;
- each strut extending in an axial direction Z between the first spine and the second spine;
- a first opening of the ocular implant extending between a first edge of the first strut and a first edge of the second strut;
- a second edge of the first strut and a second edge of the second strut defining a second opening;
- wherein an angular dimension θ of the first edge of each strut undulates as the strut extends in the axial direction Z between the first spine and the second spine; and
- wherein a radius r of an outer surface of each strut remains substantially constant as the strut extends the axial direction Z between the first spine and the second spine.
Type: Application
Filed: Sep 23, 2008
Publication Date: Mar 26, 2009
Inventors: Andrew T. Schieber (Plymouth, MN), Charles L. Euteneuer (Plymouth, MN)
Application Number: 12/236,254
International Classification: A61F 2/16 (20060101);