Drainage device for intraocular pressure control and method of manufacturing the same

Abstract

A water drainage device and a method for manufacturing the same are provided, which can prevent low intraocular pressure by reducing the effective inner diameter of the water flow path even when using a tube with a large inner diameter. The water drainage device comprises: a first tube having a first end and a second end at each of its open ends, wherein water in the anterior chamber of the eyeball flows in through the first end and the inflowed water is discharged to the subconjunctival space or to the outside through the second end; and a second tube having a third end and a fourth end at each of its open ends and coupled to the inner circumference of the first tube. Here, the third end is positioned between the first end and the second end, and the fourth end is positioned to overlap with the second end, and the first tube and the second tube are made of the same material and formed integrally.

Description

Technology Field

[0001] The present invention relates to an aqueous humor drainage device for controlling intraocular pressure that can prevent hypointraocular pressure caused by excessive outflow when draining aqueous humor from the anterior chamber to lower intraocular pressure during glaucoma surgery, and a method for manufacturing the same. Background Technology

[0002] Aqueous humor refers to the clear fluid 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'); it has properties similar to lymph. Aqueous humor plays a role in maintaining pressure within the eye.

[0003] Meanwhile, glaucoma is a progressive optic neuropathy that causes dysfunction of the optic nerve and leads to visual field defects. The primary cause of glaucoma is damage to the optic nerve resulting from elevated intraocular pressure. Intraocular pressure refers to the pressure within the eye (eyeball) and is primarily determined by the balance of aqueous humor circulation. Aqueous humor is produced in small amounts daily by the ciliary body behind the iris, and an equal amount is drained out of the eye through circulation. If too much aqueous humor is produced or if drainage is reduced due to an obstruction in the circulation flow, the pressure inside the eye rises; this process leads to increased intraocular pressure and ultimately causes glaucoma. If such elevated intraocular pressure persists, it can result in permanent vision loss. Furthermore, in cases where the optic nerve is weak, glaucoma can occur even within the normal intraocular pressure range due to pressure-induced optic nerve damage.

[0004] Since glaucoma originates from damage to the optic nerve and it is difficult to restore the already damaged area, the goal of all treatment is to prevent further damage. Treatment to lower intraocular pressure using medication is typically performed first; however, if intraocular pressure is not controlled despite the use of various drugs, or if medication cannot be used due to side effects, surgical treatments such as trabeculectomy or aqueous humor drainage device implantation are applied.

[0005] Currently, the Ahmed valve is the aqueous humor drainage device primarily used in glaucoma surgery in Korea (see US 5,071,508). In the case of the Ahmed valve, a silicone tube is inserted into the anterior chamber to drain aqueous humor, and the inner diameter of the silicone tube reaches 300 µm. Since the inner diameter of the silicone tube is excessively large and may cause hypointensity, a valve body is connected to the silicone tube to prevent this, which closes when the intraocular pressure in the anterior chamber is low and opens only when it is high.

[0006] However, when the above-mentioned valve body is inserted under the conjunctiva, it can cause a foreign body sensation in the patient, and furthermore, there are many reported cases where postoperative hypotension occurs because the membrane responsible for opening and closing the valve body does not function properly. If hypotension occurs due to excessive aqueous humor outflow, choroidal detachment and retinal folds (hypotension retinopathy) may develop. Therefore, in actual clinical practice, methods such as inserting a stent into the tube or tying the tube to reduce the inner diameter are frequently used.

[0007] Meanwhile, there is an attempt to maintain a minimum intraocular pressure (6 mmHg) without a valve body by reducing the inner diameter of the silicone tube in the drainage device. However, due to the characteristics of silicone material and extrusion molding, it is difficult to produce a tube inner diameter of 100 µm or less, and even if the tube inner diameter is 100 µm, the tube length must be at least 708 mm according to Poiseuille's law to maintain a minimum intraocular pressure of 6 mmHg, so there is a problem that it is difficult to apply to an actual eye. The problem to be solved

[0008] The problem that the present invention aims to solve is to provide a water discharge device capable of preventing low intraocular pressure by reducing the effective inner diameter of the water discharge channel even when using a tube with a large inner diameter.

[0009] Another problem that the present invention aims to solve is to provide a method for manufacturing such a waterproof drainage device.

[0010] The problems that the present invention aims to solve are not limited to those mentioned above, and other unmentioned problems will be clearly understood by those skilled in the art to which the present invention belongs from the description below. means of solving the problem

[0011] A fluid drainage device for controlling intraocular pressure according to an embodiment of the present invention for achieving the above objective comprises: a first tube having a first end and a second end at each of its open ends, wherein fluid in the anterior chamber of the eyeball flows in through the first end and the inflowed fluid is discharged to the subconjunctival space or to the outside through the second end; and a second tube having a third end and a fourth end at each of its open ends and coupled to the inner circumference of the first tube. Here, the third end is positioned between the first end and the second end, and the fourth end is positioned to overlap with the second end, and the first tube and the second tube are made of the same material and formed integrally.

[0012] The first tube and the tube above may be made of silicone.

[0013] The first tube may be formed in an annular shape with a constant inner diameter, and the second tube may be formed in an annular shape in which the inner diameter decreases from the third end to the fourth end.

[0014] It may further include a coating layer applied to the outer surface of the first tube adjacent to the second end. The coating layer may consist of a drug comprising a fibrosis inhibitor or an antibiotic; and a biodegradable polymer.

[0015] The above fibrosis inhibitor may consist of one or more selected from the group consisting of paclitaxel, 5-fluorouracil, and ibuprofen.

[0016] A method for manufacturing a waterproof drainage device for controlling intraocular pressure according to an embodiment of the present invention for achieving the above other objectives comprises the steps of: inserting a molding rod, having a diameter smaller than the inner diameter of the first tube, into a first tube manufactured by extrusion molding (the two ends of the first tube are defined as the first end and the second end, respectively); immersing the second end of the first tube in a silicone solution while the molding rod is inserted; forming negative pressure within the first tube to draw the silicone solution into the first tube; and, when the silicone solution hardens, removing the molding rod to form a second tube made of the silicone solution within the first tube (the two ends of the second tube are defined as the third end and the fourth end, respectively). Here, the third end is positioned between the first end and the second end, and the fourth end is positioned to overlap with the second end, and the first annular tube and the second annular tube are made of the same material and formed integrally.

[0017] The method may further include the step of applying a coating layer to the outer surface of the first tube adjacent to the second end. The coating layer may consist of a drug comprising a fibrosis inhibitor or an antibiotic; and a biodegradable polymer compound.

[0018] The above fibrosis inhibitor may consist of one or more selected from the group consisting of paclitaxel, 5-fluorouracil, and ibuprofen.

[0019] The first tube may have a length of 6-200 mm, an outer diameter of 140-200 µm, and an inner diameter of 70-150 µm, and the second tube may have a length of 0.5-2 mm, an outer diameter of 70-150 µm, and an inner diameter of 10-40 µm.

[0020] The above antibiotic may consist of one or more selected from the group consisting of penicillin-class antibiotics, aminoglycoside-class antibiotics, tetracycline-class antibiotics, and quinolone-class antibiotics.

[0021] The above biodegradable polymer may consist of one or more selected from the group consisting of PEG (polyethyleneglycol), PLGA (poly(lactide-co-glycolide)), SIBS (poly(styrene-b-isobutylene-b-styrene)), PGA (polyglycolide), PLA (polylactide), and PCL (polycaprolactone).

[0022] Specific details of other embodiments are included in the specific contents and drawings. Effects of the invention

[0023] As described above, according to the aqueous humor drainage device for controlling intraocular pressure and the method for manufacturing the same according to the present invention, a molding rod is inserted into a first tube with a relatively large inner diameter manufactured by extrusion molding, and after immersion in a silicone solution, a second tube with a relatively small inner diameter is formed inside the first tube using negative pressure. In the case of an aqueous humor drainage device composed of a first tube and a second tube integrally formed from the same material in this manner, the effective inner diameter or effective cross-sectional area is reduced, so that minimum intraocular pressure can be maintained even if the length of the aqueous humor drainage device is short.

[0024] In addition, the waterproof drainage device of the present invention does not require a separate opening and closing valve, so the sensation of foreign matter can be minimized. Brief explanation of the drawing

[0025] FIG. 1 is a cross-sectional view showing an eyeball with a waterproof drainage device according to one embodiment of the present invention implanted. Figure 2 is an enlarged view of the waterproof drainage device of Figure 1. FIG. 3 is a perspective view showing the waterproof drainage device of FIG. 1. FIG. 4 is a partially cutaway perspective view showing the waterproof drainage device of FIG. 3. Figure 5 is a longitudinal section of the waterproof drainage device of Figure 3 cut along the line AA'. Figure 6 is a cross-sectional view of the waterproof outflow device of Figure 3 cut along line BB'. FIG. 7 is a series of drawings sequentially illustrating a method for manufacturing a waterproof drainage device according to one embodiment of the present invention. FIG. 8 is a cross-sectional view showing a waterproof drainage device according to another embodiment of the present invention. FIG. 9 is a cross-sectional view showing a waterproof drainage device according to another embodiment of the present invention. Specific details for implementing the invention

[0026] The advantages and features of the present invention and the methods for achieving them will become clear by referring to the embodiments described below in detail 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. These embodiments are provided merely to ensure that the disclosure of the present invention is 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. Throughout the specification, the same reference numerals refer to the same components.

[0028] A water discharge device according to an embodiment of the present invention will be described in detail below with reference to FIGS. 1 to 6. FIG. 1 is a cross-sectional view showing an eyeball in which a water discharge device according to an embodiment of the present invention has been implanted. FIG. 2 is an enlarged view of the water discharge device of FIG. 1. FIG. 3 is a perspective view showing the water discharge device of FIG. 1. FIG. 4 is a partially cutaway perspective view showing the water discharge device of FIG. 3. FIG. 5 is a longitudinal section cut along line AA' of the water discharge device of FIG. 3. FIG. 6 is a transverse section cut along line BB' of the water discharge device of FIG. 3.

[0029] A water discharge device (200) according to one embodiment of the present invention is a device for controlling intraocular pressure for the treatment of glaucoma and includes a first tube (210) and a second tube (220).

[0030] The first tube (210) is manufactured by extrusion molding and is formed in the shape of a tube or cylinder. The first tube (210) is provided with a first end (212) and a second end (214) at each of the open ends. The first end (212) of the first tube (210) is positioned at the anterior (25) of the eyeball (100), and the second end (214) of the first tube (210) is positioned between the conjunctiva (30) and the sclera (10), i.e., in the subconjunctival space, or is exposed to the outside through the conjunctiva (30).

[0031] An opening is formed at each of the first end (212) and the second end (214) of the first tube (210), and a water-draining channel is formed inside the first tube (210) that communicates with these openings. Since the first end (212) is positioned at the front (25) of the eyeball (100), water (60) located at the front (25) flows into the water-draining device (200) through the first end (212). The water that flows in travels along the water-draining channel and is discharged to the subconjunctival space or to the outside through the second end (214). In this embodiment, the first tube (210) is described as a case where it is made of a single tube, but the present invention is not limited thereto and the first tube (210) may be formed by connecting a plurality of tubes to each other.

[0032] The second tube (220) is manufactured by a type of vacuum molding using the first tube (210) and the molding rod (300) as a mold, and is formed in the shape of a tube or cylinder overall. The second tube (220) is provided with a third end (222) and a fourth end (224) at each of its open ends and is coupled to the inner surface of the first tube (210). The third end (222) is positioned between the first end (212) and the second end (214), and the fourth end (224) is positioned to overlap with the second end (214).

[0033] The first tube (210) and the second tube (220) are manufactured by different molding methods but are formed as a single unit made of the same material. It is preferable that the first tube (210) and the second tube (220) be made of a material that is safe for the human body, maintains its shape well, and has flexible properties so that it bends well along the curvature of the eye. For example, the first tube (210) and the second tube (220) may be made of silicone, collagen gel, poly(methyl methacrylate), or poly(styrene-block-isobutylene-block-styrene), etc. Preferably, the first tube (210) and the second tube (220) may be made of silicone.

[0034] For example, the first tube (210) may have a length (L1) of 6-200 mm, an outer diameter (D1) of 140-200 µm, and an inner diameter (D2) of 70-150 µm. Since the first tube (210) is made of silicone or the like and manufactured by an extrusion molding method, it is difficult to make the inner diameter (D2) of the first tube (210) smaller than 70 µm.

[0035] For example, the second tube (220) may have a length (L2) of 0.5-2 mm, an outer diameter (D2) of 70-150 µm, and an inner diameter (D3) of 10-40 µm. The second tube (220) is made of the same material as the first tube (210), but since it is manufactured by a vacuum forming method using a molding rod (300) as a mold, the inner diameter (D3) of the second tube (220) can be made smaller than 40 µm by adjusting the diameter of the molding rod (300). It is preferable that the length (L2) of the second tube (220) be 1 to 70% of the length (L1) of the first tube (210).

[0036] The water (60) in the front (25) flows into the water discharge device (200) through the first end (212) of the first tube (210) and is discharged through the fourth end (224) of the second tube (220), wherein the inner diameter (D3) of the fourth end (224) is smaller than the inner diameter (D2) of the first end (212). Therefore, since the water flow velocity (V2) at the fourth end (224) increases compared to the water flow velocity (V1) at the first end (212), the probability of bacteria from outside the human body flowing back into the front (25) in this water flow (60) can be reduced.

[0037] Although not illustrated, an annular catch (not illustrated) may be formed along the outer circumference of the side or outer surface of the first tube (210). The catch or at least part of the catch may be formed in a shape in which the thickness increases from the first end (212) of the first tube (210) to the second end (214). Due to the shape of the catch, the aqueous humor drainage device (200) can be easily inserted into the eyeball (100) during surgery, but it is not easy to remove the aqueous humor drainage device (200) located on the sclera (10) to the outside after a period of time has passed since surgery. Therefore, the catch serves to prevent the aqueous humor drainage device (200) from detaching from the sclera (10) and to prevent aqueous humor from leaking around the first tube (210) in the early stages of surgery.

[0038] Generally, when a fluid passes through a pipe, the pressure difference (Δp) across the two ends of the pipe is determined by the following mathematical formula 1 according to Poiseuille's law.

[0039] [Mathematical Formula 1]

[0040]

[0041] Here, μ is 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 water is constant, the pressure difference (Δp) across the 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).

[0042] Generally, it is known that when the length (L) of the tube is 6 mm and the inner diameter (2R) of the tube is 35 µm according to mathematical formula 1, the minimum intraocular pressure (6 mmHg) for normal eye structure and function can be maintained. If there is no second tube (220) in the water discharge device (200) and the inner diameter of the first tube (210) is 100 µm, the pressure difference (Δp) drops to 0.1 mmHg or less, causing low intraocular pressure. Therefore, to prevent low intraocular pressure, the effective inner diameter or effective cross-sectional area of ​​the first tube (210) must be reduced. In the present invention, by integrally forming the second tube (220) within the first tube (210), the effective inner diameter or effective cross-sectional area of ​​the first tube (210) is significantly reduced, thereby preventing low intraocular pressure. Based on Poiseuille's law, the length (L1) and inner diameter (D2) of the first tube (210) and the length (L2) and inner diameter (D3) of the second tube (220) can be organically selected from each other so that a flow rate of 3 to 4 mL (daily production of water) is generated for 24 hours at a water pressure of 6 to 12 mmHg.

[0043] In FIG. 1, the unexplained reference numeral 20 represents the cornea, 40 represents the lens, and 50 represents the iris.

[0044] In this embodiment, the waterproof drainage device (200) is described as being used as a single complete body, but the present invention is not limited thereto. That is, the waterproof drainage device (200) may be used in a form that is joined to an existing waterproof drainage device or constitutes a part of it.

[0046] A method for manufacturing a waterproof drainage device according to an embodiment of the present invention will be described in detail below with reference to FIG. 7. FIG. 7 is a series of drawings sequentially illustrating a method for manufacturing a waterproof drainage device according to an embodiment of the present invention.

[0047] Referring to FIG. 7(a), after manufacturing a first tube (210) by extrusion molding, a molding rod (300) having a diameter smaller than the inner diameter (D2) of the first tube (210) is inserted into the first tube (210). Here, the molding rod (300) is formed in a rod shape or a cylinder shape overall. It is preferable that the length of the molding rod (300) be greater than the length (L1) of the first tube (210), and it is preferable that both ends of the molding rod (300) be exposed to the outside when the molding rod (300) is inserted into the first tube (210). It is preferable that the diameter of the molding rod (300) be smaller than the inner diameter (D2) of the first tube (210). Since the inner diameter (D3) of the second tube (220) subsequently manufactured is determined by the diameter of the molding rod (300), the diameter of the molding rod (300) may be 10 to 40 μm. It is preferable that the molding rod (300) be spaced apart from the inner surface of the first tube (210). In some cases, even if the molding rod (300) makes two-dimensional line contact with the inner surface of the second tube (220), the present invention can obtain substantially the same operation and effect.

[0048] The molding rod (300) is preferably made of a material that is easily physically separated from the silicone when the silicone solution is cured, and may be made of, for example, polypropylene, stainless steel, etc.

[0049] Referring to FIG. 7(b), a molten silicone solution (320) is prepared in a container (310), and the second end (214) of the first tube (210), with the molding rod (300) inserted therein, is immersed in the silicone solution (320).

[0050] Referring to FIG. 7(c), negative pressure is formed within the first tube (210) to draw the silicone solution (320) into the first tube (210). For example, negative pressure can be formed by connecting a negative pressure pump, etc. to the first end (212) of the first tube (210).

[0051] Referring to FIG. 7(d), the first tube (210) is separated from the container (310), and the molding rod (300) is removed once the silicone solution (320) is cured. As a result, a second tube (220) is created in which the silicone solution is cured within the first tube (210).

[0052] Referring to FIG. 7(e), the end of the first tube (210) immersed in the silicone solution (320) is cut along the CC' line.

[0053] Through the above process, the third end (222) of the second tube (220) is positioned between the first end (212) and the second end (214) of the first tube (210), and the fourth end (224) of the second tube (220) is positioned to overlap with the second end (214) of the first tube (210). Although the manufacturing methods of the first tube (210) and the second tube (220) are different from each other, the materials of the first tube (210) and the second tube (220) are the same, and since the second tube (220) is formed by curing the silicone solution (320), the first tube (210) and the second tube (220) are bonded together integrally even without a separate adhesive between them.

[0055] A waterproof drainage device according to another embodiment of the present invention will be described in detail below with reference to FIG. 8. FIG. 8 is a longitudinal cross-sectional view showing a waterproof drainage device according to another embodiment of the present invention. For convenience of explanation, members having the same function as those shown in the drawings of the previous embodiment ( FIG. 1 to 7) are indicated by the same reference numerals, and their descriptions are omitted; the following description will focus on the differences.

[0056] The first tube (210) is formed in an annular shape having a constant inner diameter (D2), and the second tube (221) is formed in an annular shape in which the inner diameter (D3) decreases from the third end (222) to the fourth end (224). In this way, when the inner diameter (D3) of the second tube (221) has different values ​​depending on the position, the water flow rate can be controlled by cutting one end (the second end and the fourth end) of the water discharge device (201) at a desired position according to the patient's condition during surgery.

[0057] The method of manufacturing the waterproof drainage device (201) according to the present embodiment is substantially the same as the method of manufacturing according to the previous embodiment, except for the following: that is, in the present embodiment, the end of the molded rod has a tapered shape.

[0059] A waterproof drainage device according to another embodiment of the present invention will be described in detail below with reference to FIG. 9. FIG. 9 is a longitudinal cross-sectional view showing a waterproof drainage device according to another embodiment of the present invention. For convenience of explanation, members having the same function as those shown in the drawings of the previous embodiment ( FIG. 1 to 7) are indicated by the same reference numerals, and their descriptions are omitted; the following description will focus on the differences.

[0060] The waterproof discharge device (202) according to the present embodiment further includes a coating layer (230) applied to the outer surface of the first tube (210) adjacent to the second end (214). The coating layer (230) may be applied to the outer surface of the first tube (210) after the silicone solution (320) is cured in FIG. 7(d), or may be applied to the outer surface of the first tube (210) after the end of the first tube (210) is cut in FIG. 7(e).

[0061] The coating layer (230) is composed of a drug and a biodegradable polymer, and the drug may be a fibrosis inhibitor or an antibiotic. After the waterproof drainage device (202) is inserted into the eye (100) and time elapses, the biodegradable polymer begins to be absorbed into the surrounding tissue and the drug gradually exerts its effect.

[0062] The fibrosis inhibitor is a substance that inhibits fibrosis from occurring in the surrounding tissue of the waterproofing device (202), and may consist of one or more selected from the group consisting of, for example, paclitaxel, 5-fluorouracil, and ibuprofen. The antibiotic may consist of one or more selected from the group consisting of penicillin-class antibiotics, aminoglycoside-class antibiotics, tetracycline-class antibiotics, and quinolone-class antibiotics. The biodegradable polymer may consist of one or more selected from the group consisting of PEG (polyethyleneglycol), PLGA (poly(lactide-co-glycolide)), SIBS (poly(styrene-b-isobutylene-b-styrene)), PGA (polyglycolide), PLA (polylactide), and PCL (polycaprolactone).

[0063] If a first end (212) of the first tube (210) is positioned at the anterior (25) of the eye (100) and a second end (214) of the first tube (210) is positioned between the conjunctiva (30) and the sclera (10), i.e., in the subconjunctival space, and the water drainage device (202) is inserted into the eye (100), it is preferable that the coating layer (230) be composed of a drug consisting of a fibrosis inhibitor and a biodegradable polymer to inhibit fibrosis around the second end (214). Since the drug or fibrosis inhibitor may cause damage to corneal endothelial cells if introduced into the anterior (25), it is preferable that the coating layer (230) be applied to only 10 to 40% of the first tube (210) from the second end (214).

[0064] If a water discharge device (202) is inserted into the eye (100) such that the first end (212) of the first tube (210) is positioned at the front (25) of the eye (100) and the second end (214) of the first tube (210) is exposed to the outside through the conjunctiva (30), it is preferable that the coating layer (230) be made of a drug consisting of an antibiotic and a biodegradable polymer to block external bacteria from penetrating through the second end (214).

[0066] Although embodiments of the present invention have been described above with reference to the attached drawings, those skilled in the art will understand that the present invention may be implemented in other specific forms without changing its technical concept or essential features. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. Explanation of the symbols

[0067] 10: Sclera 20: Cornea 25: Front 30: Conjunctiva 40: Lens 50: Iris 60: Waterproof 100: Eyeball 200, 201, 202: Waterproof drainage device 210: 1st tube 212: First section 214: Second section 220, 221: 2nd tube 222: Third section 224: Part 4 230: Coating layer 300: Formed rod 310: Courage 320: Silicone solution

Claims

Claim 1 delete Claim 2 delete Claim 3 delete Claim 4 delete Claim 5 delete Claim 6 A method for manufacturing a waterproof drainage device for controlling intraocular pressure, comprising the steps of: inserting a molding rod, having a diameter smaller than the inner diameter of the first tube, into a first tube manufactured by extrusion molding (where both ends of the first tube are defined as a first end and a second end, respectively); immersing the second end of the first tube in a silicone solution while the molding rod is inserted; forming negative pressure within the first tube to draw the silicone solution into the first tube; and, when the silicone solution hardens, removing the molding rod to form a second tube made of the silicone solution within the first tube, wherein both ends of the second tube are defined as a third end and a fourth end, respectively, wherein the third end is positioned between the first end and the second end, and the fourth end is positioned to overlap with the second end, and the first tube and the second tube are made of the same material and formed as a single unit. Claim 7 A method for manufacturing a waterproof discharge device according to claim 6, further comprising the step of applying a coating layer to the outer surface of the first tube adjacent to the second end, wherein the coating layer is composed of a drug comprising a fibrosis inhibitor or an antibiotic; and a biodegradable polymer compound. Claim 8 A method for manufacturing a waterproof drainage device according to claim 7, characterized in that the fibrosis inhibitor comprises one or more selected from the group consisting of paclitaxel, 5-fluorouracil, and ibuprofen.

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