Methods Materials Assemblies Apparatuses and Implants for Surgical Reduction of Intraocular Pressure to Suprachoidal Space Ab Externo and Subconjunctival Space

Abstract

Disclosed is an interocular fluid shunting assembly including a contact or interface plate and one or more fluid drainage tubes. According to embodiments there may be provided two tubes draining fluid to different locations. According to embodiments, a biodegradable polymer may be used to hinder fluid flow through at least one tube at initial insertion.

Claims

1. An interocular fluid shunting assembly comprising: an interface plate including one or more latching structures configured to facilitate securing of said plate to an outer surface of an eyeball; one or more fluid tubes supported by said plate, wherein each of said one or more fluid tubes includes first and second ends, at least one of which tube ends is adapted to penetrates an outer surface of an eyeball to a depth sufficient for contact with interocular fluid; a flow hindering element of biodegradable material functionally associated with at least one of the one or more fluid tubes and adapted to hinder interocular fluid flow through the functionally associated fluid tubes upon initial penetration of the tubes into the eyeball.

2. The interocular fluid shunting assembly of claim 1, wherein a surface of said plate intended for contact with an outer surface of an eyeball is of a partial spherical shape.

3. The interocular fluid shunting assembly of claim 2, wherein said latching structures configured to facilitate securing of said plate to an outer surface of an eyeball include one or more structure selected from the group consisting: (a) one or more suturing holes, (b) toothlike protrusions; and (c) surface segments with textures configured to promote bleb formation.

4. The interocular fluid shunting assembly of claim 1, wherein said one or more tubes pass through said plate.

5. The interocular fluid shunting assembly of claim 1, wherein the flow hindering element functionally associated with at least one of the fluid tubes is a biodegradable polymer clog located within an inner channel of the tube.

6. The interocular fluid shunting assembly of claim 1, wherein the flow hindering element functionally associated with at least one of the fluid tubes is a pinching element located outside the tube and physically pinches the tube.

7. The interocular fluid shunting assembly of claim 6, wherein the pinching element is a biodegradable suture wrapped around the tube.

8. The interocular fluid shunting assembly of claim 1, including two fluid shunting tubes.

9. The interocular fluid shunting assembly of claim 8, wherein one of the tubes is associated with a fluid hindering element and the other is not.

10. The interocular fluid shunting assembly of claim 8, wherein each of the tubes drains interocular fluid to a different location.

11. The interocular fluid shunting assembly of claim 10 wherein the two tubes provide for subconjunctival and suprachoroidal flow.

12. The interocular fluid shunting assembly of claim 11, providing for ab externo suprachoriodal outflow with one tube end accessing the aqueous and other tube end inserted to suprachoroidal space ab externo.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0028] The subject matter regarded as the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. The invention, however, both as to organization and method of operation, together with objects, features, and advantages thereof, may best be understood by reference to the following detailed description when read with the accompanying drawings in which:

[0029] FIG. 1 is a set of mechanical drawings of the constituent elements of an implant in accordance with embodiments of the present invention;

[0030] FIGS. 2A & 2B are illustrations of an implant according to embodiments of the present invention implanted onto and within an eye to be treated by the implant;

[0031] FIGS. 3A & 3B are prospective views of a shunt assembly in accordance with embodiments of the present invention; and

[0032] FIG. 3C is a prospective view of the shun assembly disassembled.

[0033] It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements.

DETAILED DESCRIPTION OF THE FIGURES

[0034] In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, procedures, components and assemblies have not been described in detail so as not to obscure the present invention.

[0035] The following description is made with reference to FIG. 1, FIGS. 2A & 2B and FIGS. 3A through 3C. The relevant structure of the eye will be described briefly below to provide background for the anatomical terms incorporated herein, however, it should be realized that several anatomical details have been omitted for clarity of understanding. The tough outer membrane known as the sclera covers all of the eye except that portion covered by the cornea, the thin, transparent membrane which covers the iris and the pupil. The cornea merges into the sclera at a juncture referred to as the sulcus of the sclera or as the limbus. A portion of the sclera is covered by a thin tissue called the conjunctiva. The ciliary body begins at the limbus and extends along the interior of the sclera and becomes the choroid. The choroid is a brown vascular membrane which extends along the retina back toward the optic nerve. The suprachoroidal space also serves as an additional drainage site of aqueous. The eye includes six extraocular eye muscles which control the movement of the eye in the socket. The eye muscles include the rectus muscles which include lateral, medial, superior, oblique and inferior muscles. The muscle insertion is the point at which the rectus muscles attach to the globe of the eye. The anterior segment is the portion of the globe of the eye which is anterior to the muscle insertions. The remainder of the globe which is posterior to the muscle insertions is considered the posterior segment.

[0036] It is well-known that aqueous is produced by the ciliary body and reaches the anterior chamber formed between the iris and the cornea through the pupil. In a normal eye, the aqueous is removed through the trabecular meshwork. There the aqueous passes through Schlemm's canal and through veins which merge with blood-carrying veins and into venous circulation. Intraocular pressure is maintained in the eye by the intricate balance of secretion and absorption or outflow of the aqueous in the manner described above. Glaucoma results from excessive buildup of aqueous fluid in the anterior chamber which produces an increase in intraocular pressure.

[0037] Implants for treatment of glaucoma facilitate the outflow of the aqueous from the anterior chamber of the eye. The implant comprises a pliable plate, also referred to as a pliable seton in the ophthalmic field, having oppositely disposed first and second curved surfaces, connected to two drainage tubes which extends into a first region of the eye. The seton is implanted in a second region of the eye above or beneath a layer of Tenon's capsule and sutured to the sclera. More specifically, the implant is implanted in the posterior segment of the eye. The tubes will redirect aqueous to the subconjunctival space and posterior sclera. When a scleral window is dissected beneath the plate flow will also be directed to the suprachoriodal space facilitating additional outflow. The scleral window will also further reduce biomechanical stress to the optic nerve.

[0038] The surface area of the plate is preferably in the range of approximately 37 mm2 on each side and fits between the muscles.

[0039] The Plate is 4 mm4 mm made of medical grade silicone elastomer. There is a partial cover on the superior and inferior apex. A superior and inferior tube are inserted at the apex. The superior tube connects to a superior chamber to transport aqueous to the subconjunctival space. The inferior tube connects to the inferior plate and transports to the inferior chamber that connects to both a scleral window that is dissected to the suprachoroidal space. Aqueous fluid can then drain to the suprachoroidal space and to a posterior tube connected at the back portion of the plate. The posterior tube drains aqueous to a posterior bleb that is formed separately from the subconjunctival bleb. The internal opening of each tube is 70 u allowing flow restriction to reduce the risk of hypotony. There is a PMMA plate at both the superior and inferior apex to prevent obstruction of the opening.

[0040] The implant can be inserted into the posterior segment of the eye using known ophthalmological surgical techniques. An initial incision is made in the conjunctiva and Tenon's capsule parallel to the limbus, the incision is stretched to enable the insertion of the implant. Just where the plate is to be inserted a 1.5 mm.Math.1.5 mm scleral widow to the choroid can be dissected. The plate is inserted into the second region of the eye above the scleral window, beneath the muscles superotemporally. The plate can be sutured to the sclera. Preferably, nonabsorbable nylon sutures are used in the suture holes to secure the plate or 9-0 nylon or polypropylene sutures. The drainage tube is tunneled out through the sclera and the cornea beneath Tenon's capsule and in through an incision in the region of the limbus such that the second end of the tube extends into a first region, such as the anterior chamber, of the eye of a phatic eye. The second tube can be inserted in the same manner as the first. Both tubes can be inserted in the posterior chamber pseudophakic eyes. The exposed portion of the drainage tube is then covered with a partial thickness auto scleral graft adjacent to the tube. Or scleral reinforcing element. The drainage tube may be closed with a temporary suture(s) to prevent any drainage of aqueous prior to formation of the bleb tissue over the plate. Or only one of the tubes can be tied off. In actual practice, it has been found that initially after surgery aqueous fluid will weep through a space formed between the yet to be healed incision and the drainage tube. This weeping of the aqueous fluid through the incision relieves some of the fluid pressure until the bleb has formed and the temporary suture(s) is/are removed or absorbed by the body. In one embodiment, the temporary suture(s) can be s a dissolvable suture while suture is nonabsorbable. In an alternate, but not preferred, embodiment, the temporary sutures are removed during a secondary procedure, such as a surgical procedure or an ophthalmic laser procedure. Both procedures are known to those of skill in the art.

[0041] The formation of the bleb occurs in response to the introduction of the plate into the tissue of the second region of the eye. The bleb comprises a thin layer of connective tissue which encapsulates the plate, and substantially all of the surfaces of the plate contact the tissues in the second region of the eye, thus lifting the Tenon's capsule above the sclera as shown. Typically, bleb formation occurs in the range of 1 to 8 weeks postoperatively. A dissolving suture can be used to seal the drainage tube. After removal or dissolution of the suture(s) blocking the drainage tube the aqueous flow between the tube and bleb is advantageously a patent flow, allowing both flow from the anterior chamber to the bleb, to suprachoroidal window and the posterior segment. This ensures that retrograde non-valved flow from the bleb to the anterior chamber, occurring in response to pressure on the eye from the outside, for example, when the lid is forced closed or when the eyeball is pressed on with a finger, does not adversely or harmfully affect intraocular pressure within the eye. The fluid contained in the bleb seeps through the bleb into intercellular spaces within the eye and is then removed through surrounding capillaries or lymphatics.

[0042] Advantageously, the insertion of the implant, such that a portion of the plate extends into the anterior segment, provides for a simpler insertion procedure. It is easier to suture the plate to the sclera when the suture holes are located in the anterior segment of the eye. Finally, by having anterior and posterior drainage areas on the plate the surface area of the plate can be increased. Thus, a plate can be formed to cover the sclera in the anterior segment and posterior segment of the eye. By increasing the surface area of the plate, the surface area of the bleb that forms around the plate increases. It has been shown that by increasing the surface are of the bleb that covers the sclera, increased uveoscleral outflow and reducing biomechanical scleral stress, the intraocular pressure can be decreased more significantly. Thus, this implant with an increased surface area, greater opportunity for outflow will be more effective at treating the most severe cases of glaucoma without requiring additional medications.

[0043] The flexible elastomeric material used to form parts of the present invention, and the size and elliptical shape of the plate allows the implant to be inserted much more easily than previously realized with other glaucoma treatment implants. Further, the flexible material from which the plate 38 is formed is soft and pliable which results in much less trauma and irritation to the surrounding tissues and vasculature than experienced with a rigid plate device. Thus, the pliable plate 38 significantly decreases the surgical procedure length while also minimizing tissue and vasculature damage which can occur in the insertion process.

[0044] In the preferred embodiment of the implant the plate has a profile shape that is generally spherical and conforms to the contour of the eye. Preferably, the plate is shaped like the profile of an elongated soybean. The square shape allows for symmetrical drainage of flow within the muscle space to reduce diplopia and bleb formation over the muscles and direct the flow more posteriorly.

[0045] The drainage tube has an inner diameter of 70 um and an outer diameter of 150 um. The drainage tube of the preferred embodiment 25 mm for both anterior tubes that can be cut depending on the size of the eye and 5 mm posterior.

[0046] Preferably, the temporary sutures are dissolvable sutures. The sutures can be absorbed at any time postoperatively from 1 day up to 8 weeks. Preferably, the sutures are dissolved in 1 to 6 weeks postoperatively. In the preferred embodiment, the dissolving sutures are 7-O or 8-O Vicryl. after the bleb forms, the temporary sutures are absorbed by the body, the fluid pressure in the cupped cavity drains to the suprachoroidal window, subconjunctival space and posterior portion of the eye.

[0047] As indicated above, the temporary sutures of the preferred embodiment are dissolvable sutures. In an alternate, but not preferred embodiment, the temporary sutures are removed during a secondary procedure, such as a surgical procedure or a laser procedure, after scar tissue formation. In the preferred embodiment, the temporary sutures are selected such that the sutures dissolve after the formation of the scar tissue bleb. The sutures can be absorbed at any time postoperatively from 1 day up to 8 weeks. Preferably, the sutures are dissolved in 1 to 6 weeks postoperatively. In the preferred embodiment, the dissolving sutures are 8-O Vicryl. Aqueous fluid moves posteriorly to a superior bleb, inferior container that connects to a scleral window to provide suprachoridal drainage, and the also to a posterior tube to form a more posterior bleb. Increasing the avenues for fluid drainage will reduce IOP to lower targets of 10-12 mmHG to prevent blindness from glaucoma and also allow improvement of vision from damaged retinal ganglion cells that are not dead yet. This implant with an increased surface area will be more effective at treating the most severe cases of glaucoma without requiring additional medications.

[0048] According to embodiments, there may be provided an interocular fluid shunting assembly comprising an interface plate including one or more latching structures configured to facilitate securing of said plate to an outer surface of an eyeball. There may be one or more fluid tubes supported by the plate, wherein each of said one or more fluid tubes includes first and second ends, at least one of which tube ends may be adapted to penetrates an outer surface of an eyeball to a depth sufficient for contact with interocular fluid. There may be a fluid flow hindering element of biodegradable material functionally associated with at least one of the one or more fluid tubes and adapted to hinder interocular fluid flow through the functionally associated fluid tubes upon initial penetration of the tubes into the eyeball.

[0049] A surface of said plate intended for contact with an outer surface of an eyeball may be of a partial spherical shape. The surface may include latching structures configured to facilitate securing of said plate to the outer surface of an eyeball. The latching structures may include one or more structure selected from the group consisting: (a) one or more suturing holes, (b) toothlike protrusions; and (c) surface segments with textures configured to promote bleb formation.

[0050] One or more tubes of the assembly may pass through said plate. The flow hindering element functionally associated with at least one of the fluid tubes may be a biodegradable polymer clog located within an inner channel of the tube. The flow hindering element functionally associated with at least one of the fluid tubes may be a pinching element located outside the tube and physically pinches the tube. The pinching element is a biodegradable suture wrapped around the tube.

[0051] As assembly according to embodiments may include two fluid shunting tubes. One of the tubes may be associated with a fluid hindering element and the other may not. Each of the tubes may drain interocular fluid to either the same or to a different location.

[0052] According to embodiments, the two tubes may provide for subconjunctival and suprachoroidal flow. The tubes may provide for ab externo suprachoriodal outflow with one tube end accessing the aqueous and other tube end inserted to suprachoroidal space ab externo.

[0053] Although the invention has been described with reference to specific embodiments, the description is intended to be illustrative of the invention and is not intended to be limiting. Various modifications and applications may occur to those skilled in the art without departing from the true spirit and scope of the invention as defined in the appended claims.

[0054] Functions, operations, components and/or features described herein with reference to one or more embodiments, may be combined or otherwise utilized with one or more other functions, operations, components and/or features described herein with reference to one or more other embodiments, or vice versa. While certain features of the invention have been illustrated and described herein, many modifications, substitutions, changes, and equivalents will now occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.