KR20240145132A - Drainage device for intraocular pressure control with flow control unit - Google Patents

Abstract

A drainage device capable of preventing hypotony by reducing the effective inner diameter of an aqueous humor path even when a tube having a large inner diameter is used is provided. The drainage device comprises: a tube including a first opening through which aqueous humor flows into the anterior chamber of an eye, a second opening for discharging the flowed-in aqueous humor into a subconjunctival space or the outside, and an aqueous humor path communicating the first opening and the second opening; a flow control portion extending along a longitudinal axis of the tube within the tube and controlling a flow rate of aqueous humor passing through the aqueous humor path; a first head portion formed at one end of the flow control portion exposed to the outside through the first opening and having a larger size than the first opening to prevent outflow of the flow control portion; and a second head portion formed at the other end of the flow control portion exposed to the outside through the second opening and having a larger size than the second opening to prevent outflow of the flow control portion.

Description

{Drainage device for intraocular pressure control with flow control unit}

The present invention relates to an aqueous outflow device for controlling intraocular pressure, which can prevent hypotension caused by excessive outflow when draining aqueous humor from the anterior chamber to lower intraocular pressure in glaucoma surgery.

Aqueous humor is a clear liquid that fills the space between the cornea and the iris (called the "anterior chamber") and between the iris and the lens (called the "posterior chamber"), and has properties similar to lymph. Aqueous humor plays a role in maintaining pressure inside the eye.

Meanwhile, glaucoma is a progressive optic neuropathy that causes abnormalities in the function of the optic nerve and causes visual field defects. The main cause of glaucoma is damage to the optic nerve due to increased intraocular pressure. Intraocular pressure refers to the pressure of the eye (eyeball), and is mainly determined by the balance of aqueous circulation. Aqueous humor is produced in small amounts every day in the ciliary body behind the iris, and the amount produced is discharged out of the eye through circulation. If too much aqueous humor is produced or the flow of circulation is obstructed and discharge is reduced, the pressure inside the eye increases, and through this process, intraocular pressure increases, causing glaucoma. If this increase in intraocular pressure continues, vision can be permanently lost. In addition, in cases where the optic nerve is weak, glaucoma can occur due to pressure damage to the optic nerve even at normal intraocular pressure.

Since glaucoma disease begins with damage to the optic nerve, it is difficult to restore the already damaged part, so the goal of all treatment is to prevent additional damage. Treatment to lower intraocular pressure with medication is mainly performed first, but if intraocular pressure is not controlled even with multiple medications or medications cannot be used due to side effects, surgical treatment such as trabeculectomy and implantation of an aqueous outflow device is applied.

Currently, the most commonly used aqueous outflow device for glaucoma surgery in Korea is the Ahmed valve (see US 5,071,508). In the case of the Ahmed valve, a silicone tube is inserted into the anterior chamber to drain the aqueous humor, and the inner diameter of the silicone tube is 300 um. Since the inner diameter of the silicone tube is too large to cause hypotony, to prevent this, a valve body that closes when the intraocular pressure in the anterior chamber is low and opens only when it is high is connected to the silicone tube.

However, when the above valve body is inserted under the conjunctiva, it can cause a foreign body sensation in the patient, and furthermore, there are many cases where the membrane in charge of opening and closing the valve body does not function properly, resulting in postoperative hypotony. If hypotony occurs due to excessive aqueous outflow, it can cause choroidal detachment, retinal wrinkles (hypotony retinopathy), etc. Therefore, in actual clinical practice, methods of inserting a stent into the tube or tying the tube to reduce the inner diameter are often used.

Meanwhile, there is an attempt to maintain the minimum intraocular pressure (6 mmHg) without a valve body by reducing the inner diameter of the silicone tube in the aqueous outflow device. However, due to the characteristics of the silicone material, it is difficult to produce a tube with an inner diameter of less than 100 um, and even if the tube inner diameter is 100 um, the tube length must be at least 708 mm according to Poiseuille's law to maintain the minimum intraocular pressure of 6 mmHg, so there is a problem that it is difficult to apply to an actual eye.

The problem that the present invention seeks to solve is to provide an aqueous outflow device that can prevent hypotony by reducing the effective inner diameter of the aqueous path even when using a tube with a large inner diameter.

The problems to be solved by the present invention are not limited to the problems mentioned above, and other problems not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present invention belongs from the description below.

According to one embodiment of the present invention for achieving the above object, the aqueous drainage device for controlling intraocular pressure comprises: a tube including a first opening through which aqueous fluid flows into the anterior chamber of the eye, a second opening for discharging the introduced aqueous fluid into a subconjunctival space or the outside, and an aqueous flow path communicating the first opening and the second opening; a flow control portion extending along a longitudinal axis of the tube within the tube and controlling a flow rate of the aqueous fluid passing through the aqueous flow path; a first head portion formed at one end of the flow control portion exposed to the outside through the first opening and having a larger size than the first opening to prevent leakage of the flow control portion; and a second head portion formed at the other end of the flow control portion exposed to the outside through the second opening and having a larger size than the second opening to prevent leakage of the flow control portion.

The above tube may be made of silicone, and the flow control unit may be made of suture.

The above flow control part, the first head part, and the second head part may be formed integrally by being made of the same material. In this case, the first head part and the second head part may be formed by applying heat to the flow control part exposed to the outside through the first opening and the second opening, respectively.

The inner diameter of the above tube may be 70 to 400 um, and the diameter of the flow control part may be 20 to 350 um.

A first cut portion connected to the first opening may be formed at one end of the tube. When the first head portion comes into contact with the first opening, waterproofing may flow into the inside of the tube through the first cut portion.

A second cut portion connected to the second opening may be formed at the other end of the tube. When the second head portion comes into contact with the second opening, waterproofing may be discharged outside the tube through the second cut portion.

Specific details of other embodiments are included in the specific contents and drawings.

As described above, according to the aqueous outflow device for controlling intraocular pressure according to the present invention, even if a silicone tube having an inner diameter of 100 um or more is used, the effective inner diameter or effective cross-sectional area is reduced by inserting a flow control unit into the tube, so that the minimum intraocular pressure can be maintained even if the tube length is short.

Since the waterproof drainage device of the present invention does not require a separate opening/closing valve, the foreign body sensation can be minimized.

In the present invention, a pair of head parts are formed at both ends of the flow control part to prevent the flow control part from leaking out of the tube. Here, the head part can be easily formed by applying heat to a part of the flow control part exposed outside the tube using a cautery. Accordingly, since the flow control part and the pair of head parts are formed integrally with the same material, the movement of the flow control part can be firmly controlled.

Figure 1 is a cross-sectional view showing an eyeball in which a waterproof drainage device according to one embodiment of the present invention has been implanted.
Figure 2 is an enlarged drawing of the waterproof drain device of Figure 1.
Figure 3 is a perspective view showing the waterproof drain device of Figure 1.
Figure 4 is a cross-sectional view of the waterproof drain device of Figure 3.
Figure 5 is a cross-sectional view of the waterproof drain device of Figure 3.
Figure 6 is a perspective view showing a waterproof drain device according to another embodiment of the present invention.

The advantages and features of the present invention, and the methods for achieving them, will become clearer with reference to the embodiments described in detail below together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and these embodiments are provided only to make the disclosure of the present invention complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

Hereinafter, a waterproof drainage device according to an embodiment of the present invention will be described in detail with reference to FIGS. 1 to 5. FIG. 1 is a cross-sectional view showing an eye in which a waterproof drainage device according to an embodiment of the present invention has been implanted. FIG. 2 is an enlarged view of the waterproof drainage device of FIG. 1. FIG. 3 is a perspective view showing the waterproof drainage device of FIG. 1. FIG. 4 is a longitudinal cross-sectional view of the waterproof drainage device of FIG. 3. FIG. 5 is a cross-sectional view of the waterproof drainage device of FIG. 3.

An aqueous drainage device (200) according to one embodiment of the present invention is a device for controlling intraocular pressure for treating glaucoma, and includes a tube (210), a flow control unit (240), a first head unit (241), and a second head unit (242).

The tube (210) is formed in a tube or cylinder shape overall. One end of the tube (210) is placed in the front (25) of the eyeball (100), and the other end of the tube (210) is placed between the conjunctiva (30) and the sclera (10) or is exposed to the outside through the conjunctiva (30).

A first opening (211) is formed at one end of the tube (210), a second opening (212) is formed at the other end of the tube (210), and an aqueous path (213) connecting the first opening (211) and the second opening (212) is formed inside the tube (210). Since the first opening (211) is arranged in the front (25) of the eyeball (100), aqueous fluid (60) in the front (25) flows into the aqueous drainage device (200) through the first opening (211). The aqueous fluid that flows in moves along the aqueous path (213) and is then discharged into the subconjunctival space or to the outside through the second opening (212). In this embodiment, a case where the tube (210) is formed as a single tube is described as an example, but the present invention is not limited thereto, and a plurality of tubes may be connected to each other to form a tube (210).

It is preferable that the tube (210) be made of a material that is safe for the human body, maintains its shape well, and is flexible so that it can bend well along the curvature of the eye. The tube (210) may be made of, for example, silicone, collagen gel, poly(methyl methacrylate), or poly(styrene-block-isobutylene-block-styrene). Preferably, the tube (210) may be made of silicone. The length (L1) of the tube (210) may be, for example, 5 to 140 mm, the outer diameter (D1) of the tube (210) may be, for example, 120 to 700 um, and the inner diameter (D2) of the tube (210) may be, for example, 70 to 400 um. Preferably, the length (L1) of the tube (210) can be, for example, 6 to 20 mm, the outer diameter (D1) of the tube (210) can be, for example, 140 to 200 um, and the inner diameter (D2) of the tube (210) can be, for example, 70 to 100 um.

Although not shown, an annular catch (not shown) may be formed along the outer circumference of the side or outer surface of the tube (210). The catch or at least a part of the catch may be formed in a shape whose thickness increases from one end of the tube (210) to the other end or in a shape having a triangular cross section. Due to the shape of the catch, the tube (210) can be easily inserted into the eyeball (100) during surgery, but it is not easy to remove the tube (210) located on the cornea (10) to the outside after a period of time after surgery. Therefore, the catch prevents the tube (210) from being detached from the cornea (10) and prevents the leakage of aqueous humor around the tube (210) in the early stage of surgery.

A flow control unit (240) for controlling the flow rate of body fluid or aqueous solution passing through the waterproof passage (213) of the tube (210) is disposed within the tube (210). The flow control unit (240) is formed in an overall rod-like or cylindrical shape and extends along the longitudinal axis of the tube (210). In order for aqueous solution to flow in and out through the space between the flow control unit (240) and the tube (210), the length (L2) of the flow control unit (240) is preferably larger than the length (L1) of the tube (210). The diameter (D3) of the flow control unit (240) is preferably smaller than the inner diameter (D2) of the tube (210). Therefore, the flow control unit (240) may be disposed spaced apart from the inner surface of the tube (210). While the waterproof (60) flows inside the tube (210), the flow control unit (240) and the inner surface of the tube (210) may temporarily make two-dimensional linear contact, but the flow control unit (240) may not be coupled with the tube (210) and may move or move individually inside the tube (210). The diameter (D3) of the flow control unit (240) may be, for example, 20 to 350 um. Preferably, the diameter (D3) of the flow control unit (240) may be, for example, 30 to 70 um. In this embodiment, a case where one flow control unit (240) is arranged inside the tube (210) is described as an example, but the present invention is not limited thereto, and a plurality of flow control units (240) may be connected in the longitudinal direction and arranged inside the tube (210).

The flow control unit (240) may be made of a suture, stainless steel, polypropylene, or the like. Preferably, the flow control unit (240) may be made of a non-absorbable suture that is not absorbed into the surrounding tissue over time, such as a prolene suture. In addition, the flow control unit (240) may be made of an absorbable suture that is absorbed into the surrounding tissue over time, such as a vicryl suture. In this embodiment, the case where the flow control unit (240) is made of a single suture is described as an example, but the present invention is not limited thereto, and the flow control unit (240) may be made of a plurality of sutures or a bundle of sutures, as needed. For example, the flow control unit (240) may be made of three sutures each having an outer diameter of 20 um instead of a single suture each having an outer diameter of 60 um.

When the flow control unit (240) is made of an absorbable suture, after two weeks of insertion of the aqueous outflow device (200) into the eyeball (100), the flow control unit (240) begins to be absorbed into the surrounding tissue, thereby increasing the effective inner diameter or effective cross-sectional area of the tube (210). At this time, fibrosis occurs in the tissue surrounding the device, thereby decreasing the absorption rate of the aqueous humor into the surrounding tissue. Accordingly, even if the flow rate of the aqueous humor increases, the absorption rate of the aqueous humor decreases, thereby achieving an overall balance in the outflow of the aqueous humor. Furthermore, since the effective inner diameter or effective cross-sectional area of the tube (210) increases due to the absorption of the suture, the possibility of stenosis due to proteins, etc. in the future can be prevented, and therefore the flow control unit (240) may be made of an absorbable suture.

The first head part (241) is formed at one end of the flow control part (240) exposed to the outside through the first opening (211). The second head part (242) is formed at the other end of the flow control part (240) exposed to the outside through the second opening (212). For example, the first head part (241) and the second head part (242) may be formed in a spherical shape. It is preferable that the size or diameter (D4) of the first head part (241) and the second head part (242) be larger than the size or diameter (D2) of the first opening (211) and the second opening (212), respectively. The first head part (241) and the second head part (242) fix the flow control part (240) within the tube (210) to prevent the flow control part (240) from leaking out of the tube (210).

It is preferable that the flow control unit (240), the first head unit (241), and the second head unit (242) are formed integrally by being made of the same material. For example, the first head unit (241) and the second head unit (242) can be formed by applying heat with a cautery to the flow control unit (240) exposed to the outside through the first opening (211) and the second opening (212), respectively. If the flow control unit (240) is formed of a plurality of sutures, the first head unit (241) and the second head unit (242) can be formed by applying heat with a cautery to both ends of the suture bundle.

In general, when a fluid passes through a pipe, the pressure difference (Δp) across the two ends of the pipe is determined by the following mathematical equation 1 according to Poiseuille's law.

[Mathematical Formula 1]

Here, μ is the viscosity, L is the length of the pipe, Q is the volume flow rate, and R is the radius. When the volume flow rate of the water is constant, the pressure difference (Δp) across the two ends of the pipe is proportional to the length of the pipe (L) and inversely proportional to the fourth power of the radius of the pipe (or the square of the cross-sectional area).

In general, it is known that when the length (L) of the tube is 6 mm and the inner diameter (2R) of the tube is 35 um by mathematical expression 1, the minimum intraocular pressure (6 mmHg) for normal eye structure and function can be maintained. If there is no flow control unit (240) in the aqueous outflow device (200) and the inner diameter of the tube (210) is 100 um, the pressure difference (Δp) falls below 0.1 mmHg, causing hypotony. Therefore, in order to prevent hypotony, the inner diameter or cross-sectional area of the tube (210) must be reduced. In the present invention, by inserting the flow control unit (240) into the tube (210), the effective inner diameter or effective cross-sectional area of the tube (210) is greatly reduced, thereby preventing hypotony. The flow control unit (240) may be formed of one suture or a plurality of sutures, as necessary.

Based on Poiseuille's law, the length (L1) and the inner diameter (D2) of the tube (210) and the length (L2) and the diameter (D3) of the flow control portion (240) can be organically selected to generate a flow rate of 3 to 4 mL (daily production volume of waterproof water) for 24 hours at a water pressure of 6 to 12 mmHg. The tube (210) can be made of, for example, hydrophobic silicone or hydrophilic silicone. Preferably, for infection prevention, the tube (210) can be made of hydrophilic silicone to which an infection inhibitor (for example, silver ion) is added. Since hydrophilic silicone allows a smoother waterproof flow inside the tube than hydrophobic silicone, the diameter of the flow control portion can be made larger for a tube of the same size.

In Figure 1, the unexplained drawing symbol 20 represents the cornea, 40 represents the lens, and 50 represents the iris.

In this embodiment, a case where the waterproof drain device (200) is used as a complete body is described as an example, but the present invention is not limited to this. That is, the waterproof drain device (200) may be used in a form that is joined to or forms a part of an existing waterproof drain device.

Hereinafter, a waterproof drain device according to another embodiment of the present invention will be described in detail with reference to FIG. 6. FIG. 6 is a perspective view showing a waterproof drain device according to another embodiment of the present invention. For convenience of explanation, components having the same function as each component shown in the drawings of the previous embodiments (FIGS. 1 to 5) are indicated by the same reference numerals and their descriptions are omitted, and the following description focuses mainly on differences.

In the case of the waterproof drain device (202) according to the present embodiment, a first cut portion (221) connected to a first opening (211) is formed at one end of the tube (210), and a second cut portion (222) connected to a second opening (212) is formed at the other end of the tube (210). If the first head portion (241) comes into contact with the first opening (211) due to movement of the flow control portion (240), waterproof water can flow into the tube (210) through the first cut portion (221). If the second head portion (242) comes into contact with the second opening (212) due to movement of the flow control portion (240), waterproof water can be discharged to the outside of the tube (210) through the second cut portion (222). In this embodiment, the first cut portion (221) and the second cut portion (222) are described as structures in which a portion of the end of the tube (210) is cut, but the present invention is not limited thereto and may include cut portions of various shapes. For example, the cut portion may be formed by cutting the end of the tube (210) in a diagonal direction with respect to the longitudinal axis.

Although the embodiments of the present invention have been described with reference to the attached drawings, those skilled in the art will understand that the present invention can be implemented in other specific forms without changing the technical idea or essential features thereof. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive.

10: cornea
20: Cornea
25: Forward
30: Conjunctiva
40: Lens
50: Redness
60: Waterproof
100: Eyeball
200, 202: Waterproofing device
210: Tube
211: 1st opening
212: Second opening
213: Waterproof Euro
221: First incision
222: Second incision
240: Flow control unit
241: First Head Section
242: Second Head Section

Claims (5)

As an aqueous outflow device for controlling intraocular pressure,
A tube including a first opening through which aqueous humor flows into the anterior chamber of the eye, a second opening through which the aqueous humor flows out into the subconjunctival space or the outside, and an aqueous humor passage connecting the first opening and the second opening;
A flow control unit extending along the longitudinal axis of the tube within the tube and controlling the flow rate of waterproof water passing through the waterproof passage;
A first head portion formed at one end of the flow control portion exposed to the outside through the first opening and having a larger size than the first opening to prevent leakage of the flow control portion; and
A waterproof drain device including a second head portion formed at the other end of the flow control portion exposed to the outside through the second opening and having a larger size than the second opening to prevent leakage of the flow control portion. In the first paragraph,
A waterproof drainage device characterized in that the tube is made of silicone and the flow control part is made of a suture. In the first paragraph,
The above flow control unit, the first head unit and the second head unit are formed integrally from the same material,
A waterproof drain device characterized in that the first head portion and the second head portion are formed by applying heat to the flow rate control portion exposed to the outside through the first opening portion and the second opening portion, respectively. In the first paragraph,
A waterproof drainage device, characterized in that the inner diameter of the tube is 70 to 400 um and the diameter of the flow control part is 20 to 350 um. In the first paragraph,
A first cut portion connected to the first opening is formed at one end of the tube, and when the first head portion comes into contact with the first opening, waterproofing flows into the tube through the first cut portion.
A waterproof drain device characterized in that a second cut portion connected to the second opening is formed at the other end of the tube, and when the second head portion comes into contact with the second opening, waterproof water is discharged to the outside of the tube through the second cut portion.

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