# Patent

## Title
Debris clearance system for an ocular implant

## Abstract

An IOP control system for treatment of an ocular condition includes a drainage device sized for implantation into the eye of the patient, the drainage device including a fluid flow pathway to allow the flow of fluid from an inlet port to an outlet port. The drainage device also includes a flow system disposed within the drainage device and including a displaceable portion forming a part of the fluid flow pathway, the displaceable portion being displaceable via a magnetic field. An actuation system may be physically separate from the drainage device and may be configured to cooperate with the displaceable portion to displace the displaceable portion via the magnetic field to set free buildup or debris in the flow pathway.

## Background
FIELD OF THE INVENTION
The present disclosure relates generally to implants for treating an ocular condition and more particularly, to systems and methods for clearing debris that may clog or prevent desired operation of the implant.
BACKGROUND
Glaucoma, a group of eye diseases affecting the retina and optic nerve, is one of the leading causes of blindness worldwide. Most forms of glaucoma result when the intraocular pressure (IOP) increases to pressures above normal for prolonged periods of time. IOP can increase due to high resistance to the drainage of the aqueous humor relative to its production. Left untreated, an elevated IOP causes irreversible damage to the optic nerve and retinal fibers resulting in a progressive, permanent loss of vision.
FIG. 1 is a diagram of the front portion of an eye that helps to explain the processes of glaucoma. In FIG. 1, representations of the lens 10, cornea 20, iris 30, ciliary body 40, trabecular meshwork 50, and Schlemm's canal 60 are pictured. Anatomically, the anterior segment of the eye includes the structures that cause elevated IOP which may lead to glaucoma. Aqueous humor fluid is produced by the ciliary body 40 which lies beneath the iris 30 and adjacent to the lens 10 in the anterior segment of the eye. This aqueous humor washes over the lens 10 and iris 30 and flows to the drainage system located in the angle of the anterior chamber. The angle of the anterior chamber, which extends circumferentially around the eye, contains structures that allow the aqueous humor to drain. The trabecular meshwork 50 is commonly implicated in glaucoma. The trabecular meshwork 50 extends circumferentially around the anterior chamber. The trabecular meshwork 50 seems to act as a filter, limiting the outflow of aqueous humor and providing a back pressure that directly relates to IOP. Schlemm's canal 60 is located beyond the trabecular meshwork 50. Schlemm's canal 60 is fluidically coupled to collector channels (not shown) allowing aqueous humor to flow out of the anterior chamber. The two arrows in the anterior segment of FIG. 1 show the flow of aqueous humor from the ciliary body 40, over the lens 10, over the iris 30, through the trabecular meshwork 50, and into Schlemm's canal 60 and its collector channels.
One method of treating glaucoma includes implanting a drainage device in a patient's eye. The drainage device includes a pathway through which aqueous flows from the anterior chamber in the eye to a drainage site, relieving excessively high IOP pressure. In some instances however, over the course of treatment with the drainage device, debris or deposits may accumulate or build-up in the flow pathway. These debris and deposits may eventually decrease the flow capacity of the drainage device. This in turn may decrease the effectiveness of the drainage device as a treatment for elevated IOP.
The system and methods disclosed herein overcome one or more of the deficiencies of the prior art.
SUMMARY
In an exemplary aspect, the present disclosure is directed to an IOP control system for treatment of an ocular condition of a patient. The IOP control system may include a drainage device sized for implantation into the eye of the patient, and the drainage device may include a housing including an inlet port and an outlet port, a fluid flow pathway extending through the housing from the inlet port to the outlet port to allow the flow of fluid from the inlet port to the outlet port, and a flow system disposed within the drainage device and including a displaceable portion forming a part of the fluid flow pathway, the displaceable portion being displaceable via a magnetic field. An actuation system may be physically separate from the drainage device and may be configured to cooperate with the displaceable portion to overextend the displaceable portion via the magnetic field to set free buildup or debris in the flow pathway.
In an aspect, the displaceable portion comprises a first base layer and a second metallic layer connected with the base layer. In an aspect, the displaceable portion comprises a flexible membrane, the metallic layer being carried on the flexible membrane. In an aspect, the flow system includes a chamber with an opening to an outlet from the chamber, the displaceable portion being disposed in a position opposite the opening to the outlet. In an aspect, the flow system includes a boss, the outlet extending through the boss. In an aspect, the actuation system is an electromagnetic magnet. In an aspect, the flow pathway includes a region of minimum spacing thickness, the displaceable portion forming a part of the region of minimum spacing thickness. In an aspect, the displaceable portion is biased to a position that blocks fluid flow through the outlet. In an aspect, the housing comprises a chamber, the displaceable portion being disposed within the chamber.
In an exemplary aspect, the present disclosure is directed to an IOP control system for treatment of an ocular condition. The IOP control system may include a drainage device sized for implantation into the eye of the patient. The drainage device may include a fluid flow pathway extending through the housing from the inlet port to the outlet port to allow the flow of fluid from the inlet port to the outlet port; and may include a flow system disposed within the drainage device and configured to regulate flow of aqueous humor through the fluid flow pathway. The flow system may include a displaceable portion forming a portion of the fluid flow pathway. The displaceable portion may be responsive to pressure changes to increase and decrease the cross-sectional area of the fluid flow pathway. The flow system may also include a magnetic portion carried on the displaceable portion, the magnetic portion configured to be responsive to a magnetic field to move the displaceable portion to increase and decrease the cross-sectional area of the fluid flow pathway.
In an exemplary aspect, the present disclosure is directed to a method of clearing buildup or debris in an ocular implant. The method may include directing aqueous humor fluid flow along a fluid pathway in the ocular implant past a constriction in the fluid flow pathway adjacent a displaceable portion at a first position; displacing the displaceable portion to a second position to increase the width of the fluid flow pathway at the constriction so that buildup or debris received at the constriction adjacent the displaceable portion advances along the fluid flow pathway; and allowing the displaceable portion to return toward the first position.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory in nature and are intended to provide an understanding of the present disclosure without limiting the scope of the present disclosure. In that regard, additional aspects, features, and advantages of the present disclosure will be apparent to one skilled in the art from the following detailed description.



BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings illustrate embodiments of the devices and methods disclosed herein and together with the description, serve to explain the principles of the present disclosure.
FIG. 1 is a diagram of the front portion of an eye.
FIG. 2 is an illustration of an exemplary IOP control system according to the principles of the present disclosure.
FIG. 3 is a stylized illustration of a cross-sectional view of an exemplary ocular implant according to the principles of the present disclosure.
FIG. 4 is a stylized illustration of a cross-sectional view of an exemplary ocular implant according to the principles of the present disclosure.
FIG. 5 is a stylized illustration of a cross-sectional view of an exemplary ocular implant according to the principles of the present disclosure.



DETAILED DESCRIPTION
For the purposes of promoting an understanding of the principles of the present disclosure, reference will now be made to the embodiments illustrated in the drawings, and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the disclosure is intended. Any alterations and further modifications to the described devices, instruments, methods, and any further application of the principles of the present disclosure are fully contemplated as would normally occur to one skilled in the art to which the disclosure relates. In particular, it is fully contemplated that the features, components, and/or steps described with respect to one embodiment may be combined with the features, components, and/or steps described with respect to other embodiments of the present disclosure. For simplicity, in some instances the same reference numbers are used throughout the drawings to refer to the same or like parts.
The present disclosure relates generally to methods and an IOP control system arranged to permit flow from an anterior chamber of the eye to a drainage site. The system provides a system that may be used to loosen and flush buildup and debris that accumulate in an implant of the IOP control system. The system includes a displaceable flow limiter in an ocular implant that may be displaced by an external actuation system. In some examples, this includes using a magnet as the external actuation system and a magnetic material on the flow limiter. When the flow limiter is displaced by the magnetic field generated by the magnet, buildup and accumulated debris are free to flush or advance through the implant toward the drainage site. Removal of the external actuation system allows the implant to return to its prior state, without the inhibiting buildup or debris.
FIG. 2 shows an exemplary system 100 for treating an ocular condition. The system 100 includes an ocular implant 102 and a remotely disposed external actuation system 104. The ocular implant 102 may be implantable within an eye according to one exemplary aspect of the present disclosure, and in the embodiment shown, is disposed on the globe of an eye. The implant 102 includes a body referred to herein as a plate 106 and a drainage tube 108 that extends from the plate 106. The plate 106 is arranged to carry various components of an IOP control system, and may include a valve, pump, transducers or sensors, processing system and memory, drug delivery components, a power source or other components that may be used to either control the implant 102 or otherwise treat ocular conditions. As shown, the drainage device 102 includes a single hollow drainage tube 108. Other embodiments include a plurality of tubes or a plurality of lumens cooperating together to permit fluid to flow through the drainage device 102. Aqueous humor may drain through the drainage device 102 from the anterior chamber 70 to the drainage site to alleviate elevated intraocular pressure conditions.
The drainage device 102 is sized to extend from the anterior chamber 70 (FIG. 1) of the eye to a drainage site in the eye, thereby bridging the anterior chamber 70 and the drainage site to provide an auxiliary flow path for aqueous humor, bypassing the flow-resistive conventional pathway through the trabecular meshwork and shunting aqueous humor directly to the drainage site.
The plate 106 is configured to fit at least partially within the subconjunctival space and is sized for example within a range between about 15 mm×12 mm to about 30 mm×15 mm and has a thickness less than about 2 mm thick and preferably less than about 1 mm thick. The plate 106 may be formed to the radius of the eye globe (about 0.5 inches). It may be rigid and preformed with a curvature suitable to substantially conform to the globe or it may be flexible to conform to the globe. Some embodiments are small enough that conforming to the globe provides little benefit in comfort or implantation technique. The above dimensions are exemplary only, and other sizes and arrangements are contemplated.
When implanted, the plate 106 may be located in the subconjunctival pocket between the conjunctiva and sclera. It may be generally located on an ocular quadrant commonly used for conventional glaucoma drainage devices with plates; that is, it may be centered such that it is equidistant from the neighboring ocular muscles that define the ocular quadrant chosen for implantation. The drainage tube 108 is sized to bridge the anterior chamber and the plate 106 in the subconjunctival pocket to provide an auxiliary flow path for aqueous humor, bypassing the flow-resistive conventional pathway through the trabecular meshwork and shunting aqueous humor directly to a drainage site.
The external actuation system 104 is separate from and arranged to be spaced apart from the eye. As is described in greater detail below, the external actuation system 104 generates and emits a magnetic field, such as for example, a static magnetic field or electromagnetic field that may be received at the drainage device 102. As will be explained below, the magnetic field may cooperate with the implant 102 to actuate a flow control portion of the implant to clear build-up or debris that may otherwise affect drainage flow through the implant 102.
FIG. 3 shows a stylized illustration of a cross-sectional view of a portion of the implant 102. Referring to FIG. 3, the plate 106 forms a housing 118 that includes a flow control portion 120 disposed in a central chamber 122, with an inlet 124 and an outlet 126 leading to and from the flow control chamber 122. In FIG. 3, the implant 102 is arranged so that a bottom portion of the housing 118 is adjacent the scleral wall 80 and the top portion of the implant 102 is arranged facing outward from the eye globe, and may be below the bleb wall 85.
The inlet 124 may fluidically connect to the drainage tube 108 and may receive aqueous through the drainage tube when the implant 102 is disposed within an eye of a patient. The outlet 126 leads from the central chamber 122 to a drainage exit disposed at a drainage site.
The flow control portion 120 comprises a valve that may be used to regulate flow of aqueous through the plate 106. The flow control portion 120 comprises a valve membrane 130, a central flow limiter 132 carried by or forming a part of the membrane 130, and an elevated portion 134 that is disposed to interface with or cooperate with the central flow limiter 132.
The valve membrane 130 extends from one side or surface of the chamber 122 to the other and is configured and arranged to support the central flow limiter 132. The valve membrane 130 may be formed of parylene, glass, or other material. It may be a membrane formed of an elastically deformable material including without limitation, materials such as a silicone, silicon nitride, silicone elastomer, polyimide, parylene and others. In the example shown, the valve membrane 130 is a circular material secured at its periphery to the housing 118. In other embodiments, the housing 118 and the valve membrane 130 are formed so that the membrane has a non-circular shape, including oval, substantially rectangular, or square, for example. Other shapes are also contemplated.
The central flow limiter 132 limits the flow rate of the aqueous from the chamber 122 and through the outlet 126. In the embodiment shown, the flow limiter 132 is disposed opposite an opening 136 to the outlet 126 and configured to displace relative to the opening 136 to increase and decrease the size of the fluid flow pathway leading to the outlet 126. Due to its structure and its connection with the flexible valve membrane 130, the flow limiter 132 is configured to physically displace in a manner increasing or decreasing the distance from the flow opening 136.
In the example shown the central flow limiter 132 includes a base structure 129 and a magnetic layer 131. In some embodiments, the base structure 129 is formed of a structure different than the structure of the membrane 130. In some examples, the base structure 129 may be formed of the same material as the membrane but may have a different thickness. In some examples, the base structure 129 may be formed of a material different than the material of the membrane. In some examples, the base structure 129 has the same structure as, and is merely a portion of, the membrane 130.
The magnetic layer 131 is formed of a material having magnetic properties, such as a ferrous metal, for example. In some embodiments, the magnetic layer 131 is magnetized while in other embodiments, the magnetic layer 131 is merely responsive to magnetic fields. The magnetic layer 131 may be deposited onto or may otherwise be connected with the base structure 129 and then the base structure 129 may be connected to or may form a part of the flexible membrane 130.
The elevated portion 134 is optional and serves as a seat or stable structure that cooperates with the central flow limiter 132 to regulate or control flow through the flow control portion 120. In this embodiment, the elevated portion 134 is a boss extending into the chamber 122. The opening 136 to the outlet 126 is disposed in the boss through the surface facing the central flow limiter 132. When pressure in the inlet 124 is greater than pressure in the outlet 126, the pressure pushes the central flow limiter 132 away from the elevated portion 134. This permits aqueous to flow from the inlet 126 and chamber 122 through the opening 136 to the outlet 124, providing IOP pressure relief. Likewise, when the pressures become more equal, the biased nature of the flexible membrane 130 results in the central flow limiter 132 coming closer to and potentially resting on the elevated portion 134, thereby covering the outlet path and reducing or eliminating flow through the flow control portion 120. In this manner, the flow control portion 120 helps regulate IOP and maintain IOP in acceptable limits.
FIG. 3 shows the flow control portion 120 in a regular operational drainage state. In this condition, aqueous flows through the flowpath formed by the inlet 124, the chamber 122, and the outlet 126. As can be seen, during regular operational drainage, the region adjacent the central flow limiter 132 is also a region of minimum spacing thickness, meaning in this region, the width of the fluid flow pathway may be minimal. Accordingly, this region of minimum spacing thickness in the flow pathway may act as a constriction site in the fluid flow pathway.
FIG. 4 shows the portion of the implant 102 as it may appear a period of time after being implanted in a patient to control and regulate IOP. Over time, some debris or other materials may build-up or accumulate adjacent the flow limiter 132 or other portion of the membrane 130. Here, the build-up occurs in the region of minimum spacing thickness at the constriction site. In this embodiment, the build-up or debris, referenced herein by the numeral 140, is disposed adjacent the elevated portion 134. In this condition, the flow control portion 120 may lose some functionality, as the membrane 130 and the central flow limiter 132 may not be capable of responding to the fluctuating pressures on the inlet and outlet sides of the flow control portion 120. That is, the build-up or debris 140 may limit the range or motion that the flow limiter may travel.
As indicated above, the implant 102 in the embodiment in FIGS. 3 and 4 is arranged so that the bottom portion of the housing 118 is adjacent the scleral wall 80 and the top portion of the implant 102 is arranged facing outward from the eye. As such, the implant 102 is arranged so that the region of minimum spacing thickness is closer to the scleral wall 80 than is the central flow limiter 132. Accordingly, as shown in FIG. 5, when the central flow limiter displaces away from the scleral wall, the flow pathway width at the region of minimum spacing thickness increases.
FIG. 5 shows the operation of the system 100 in an overextended state as it clears the build-up or debris 140. In FIG. 5, the external actuation system 104 is brought into the proximity of the implant 102, and the magnetic features of the external actuation system 104 cooperate with the implant 102 to clear the build-up or debris 140. Here, the external actuation system 104 is disposed so that its magnetic field reaches to the implant 102, and more particularly, to the magnetic layer 131 of the flow limiter 132. In this embodiment, the magnetic force attracts the magnetic layer 131, fully displacing the flow limiter 132 away from the opening 136 to the outlet 126 and against the biasing force of the flexible membrane 130. In this embodiment, the magnetic field may overextend the membrane 130.
As used herein, the term “overextend” means to displace the flow limiter 132 further than when it is displaced during normal operation.
By displacing the flow limiter to such a large degree, the constriction or region of minimum spacing thickness in the flow pathway is relieved. This allows the build-up and debris 140 to freely flow across the elevated portion 134 and into the outlet 126, where it may be expelled to the drainage site. After a set period of time, such as, for example, 5 seconds or 10 seconds, or some other period of time, the user may remove the external actuation system 104 so that the metallic layer 131 is no longer in the magnetic field. When this occurs, the flow limiter 132, under the biasing load from the flexible valve membrane 130, returns to its natural state. The valve may then regulate in the manner described with reference to FIG. 3, where the valve can operate completely free from, or partially free from, interference from build-up and debris.
In some instances, the process of clearing the buildup and debris may be performed on a maintenance schedule, such as, for example, about once a month. Different period of times, both longer and shorter are also contemplated. In addition, in some instances, the external actuation system may hold open the valve for a longer period of time than described above. The period of time may be in minutes or hours if desired.
The present disclosure presents a system and method for removing build-up and debris that may impede aqueous flow or that may impede proper operation of a glaucoma drainage device. By being able to displace elements of the valve, the debris and build-up may flow through the valve, clearing it, and returning functionality to the implant. This may result in an implant with a longer useful life, reducing the likelihood that a replacement implant may be needed. This results in less cost and less inconvenience to a patient.
Persons of ordinary skill in the art will appreciate that the embodiments encompassed by the present disclosure are not limited to the particular exemplary embodiments described above. In that regard, although illustrative embodiments have been shown and described, a wide range of modification, change, and substitution is contemplated in the foregoing disclosure. It is understood that such variations may be made to the foregoing without departing from the scope of the present disclosure. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the present disclosure.

## Claims

1. An IOP control system for treatment of an ocular condition of a patient, comprising:
a drainage device sized for implantation into the eye of the patient and including:
a housing including an inlet port and an outlet port;
a fluid flow pathway extending through the housing from the inlet port to the outlet port to allow the flow of fluid from the inlet port to the outlet port; and
a flow system disposed within the drainage device and including a displaceable portion forming a part of the fluid flow pathway, the displaceable portion being displaceable via a magnetic field; and

an actuation system physically separate from the drainage device and configured to cooperate with the displaceable portion to overextend the displaceable portion via the magnetic field to set free buildup or debris in the flow pathway;
wherein the displaceable portion is displaceable in a first direction to an extended position by a pressure difference between an inlet pressure at the inlet port and an outlet pressure at the outlet port and is displaceable in the first direction to an overextended position by the magnetic field.

2. The IOP control system of claim 1, wherein the displaceable portion comprises a first base layer and a second metallic layer connected with the base layer.

3. The IOP control system of claim 2, wherein the displaceable portion comprises a flexible membrane, the metallic layer being carried on the flexible membrane.

4. The IOP control system of claim 1, wherein the flow system includes a chamber with an opening to an outlet from the chamber, the displaceable portion being disposed in a position opposite the opening to the outlet.

5. The IOP control system of claim 4, wherein the flow system includes a boss, the outlet extending through the boss.

6. The IOP control system of claim 1, wherein the actuation system is an electromagnetic magnet.

7. The IOP control system of claim 1, wherein the flow pathway includes a region of minimum spacing thickness, the displaceable portion forming a part of the region of minimum spacing thickness.

8. The IOP control system of claim 1, wherein the housing comprises a chamber, the displaceable portion being disposed within the chamber.

9. An TOP control system for treatment of an ocular condition of a patient, comprising:
a drainage device sized for implantation into the eye of the patient and including:
a housing including an inlet port and an outlet port;
a fluid flow pathway extending through the housing from the inlet port to the outlet port to allow the flow of fluid from the inlet port to the outlet port; and
a flow system disposed within the drainage device and including a displaceable portion forming a part of the fluid flow pathway, the displaceable portion being displaceable via a magnetic field and biased to a position that blocks fluid flow through the outlet port; and

an actuation system physically separate from the drainage device and configured to cooperate with the displaceable portion to overextend the displaceable portion via the magnetic field to set free buildup or debris in the flow pathway;
wherein the displaceable portion is displaceable in a first direction to an extended position by a pressure difference between an inlet pressure at the inlet port and an outlet pressure at the outlet port and is displaceable in the first direction to an overextended position by the magnetic field.

10. The IOP control system of claim 9, wherein the displaceable portion comprises a base layer and a magnetic layer disposed on the base layer.

11. The TOP control system of claim 10, wherein the base layer comprises a flexible membrane portion and a base structure, the magnetic layer being disposed on the base structure.