Gel type glaucoma drainage tube and implantation device

Abstract

The utility model discloses a gel type glaucoma drainage tube and implantation device, the drainage tube comprises an inner tube and a fixing part sleeved outside the inner tube, both the inner tube and the fixing part are made of hydrogel, and the rehydration expansion multiple of the inner tube is larger than that of the fixing part. The fixing portion with small expansion times is fixed outside the inner tube, so that the size of the drainage channel of the inner tube is kept stable, stability of resistance of a tube cavity is guaranteed, and stable intraocular pressure can be maintained after the drainage tube is implanted.

Description

Technical Field

[0001] The utility model belongs to the technical field of medical equipment, and specifically relates to a gel-type glaucoma drainage tube and an implantation device. Background Art

[0002] Glaucoma is an irreversible blinding eye disease, and lowering intraocular pressure is currently the only effective treatment for glaucoma. According to the different principles of reducing intraocular pressure, implants are divided into internal drainage and external drainage implants. Internal drainage is through the trabecular meshwork bypass and the suprachoroidal space. External drainage is through subconjunctival drainage and ocular surface drainage. Surgical methods include traditional filtering surgery, minimally invasive internal drainage surgery, and glaucoma drainage device implantation. Among them, traditional filtering surgery and glaucoma drainage implantation are both based on the principle of external drainage. Trabeculectomy is a representative of traditional filtering surgery, but for refractory glaucoma, it is difficult to establish an effective filtration channel due to complications related to filtering blebs, and the success rate is only 11%-52%. Relevant data show that complications such as choroidal effusion (17%), wound leakage (11%), shallow anterior chamber (10%), and hyphema (8%) may occur in the early stage after trabeculectomy, resulting in the surgery greatly damaging the ocular surface structure even if it is successful, so it is not an ideal treatment method.

[0003] The application of subconjunctival minimally invasive glaucoma drainage surgery in the field of anti-glaucoma treatment has gradually increased, and a variety of minimally invasive glaucoma drainage devices have been used for minimally invasive treatment of anti-glaucoma. In the 1970s and 1980s, Ahmed and Ex-PRESS were already used clinically by doctors. Similar to the principles and operation methods of filtration surgery, these drainage devices require the creation of conjunctival flaps and scleral flaps, and the surgical trauma is relatively large. As one of the drainage devices, the glaucoma drainage tube can create a permanent channel through the sclera, allowing the aqueous humor to flow from the anterior chamber into the subconjunctival space, while reducing intraocular pressure, it also reduces the surgical trauma caused by the creation of scleral flaps and conjunctival flaps.

[0004] XEN45, made from pig skin gelatin cross-linked with glutaraldehyde, has a uniform inner diameter (gel drainage tube length: 6 mm, inner diameter: 45 μm, outer diameter: 150 μm) Gel stents are used to treat glaucoma. They only require a tiny self-closing clear corneal incision through the bulbar conjunctiva. After implantation, a small filtration bleb is produced in the bulbar conjunctiva due to the fistula effect. This process has almost no interference with the conjunctiva and subconjunctival tissue. However, clinical literature studies have shown that 11.8% (n = 8) of catheter displacement occurred (Smith, M., Charles, R., Abdel-Hay, A. et al. 1-year outcomes of the Xen45 glaucoma implant. Eye 33, 761-766 (2019)) and 2.4% (n = 1) had low intraocular pressure problems (De Gregorio, A., Pedrotti, E., Russo, L. et al. Minimally invasive combined glaucoma and cataract surgery: clinical results of the smallest ab interno gel stent. Int Ophthalmol 38, 1129-1134 (2018)). Therefore, it is necessary to design a gel-type micron-scale drainage tube that can maintain intraocular pressure stability and reduce displacement and slippage. Utility Model Content

[0005] In order to solve the above-mentioned technical problems, reduce the risk of displacement and low intraocular pressure after glaucoma drainage tube implantation, avoid secondary injury to patients caused by displacement or slipping of the drainage tube, improve the treatment effect of the surgery, and alleviate the pain of high intraocular pressure in patients, the utility model provides the following technical solutions.

[0006] In a first aspect, the utility model provides a gel-type glaucoma drainage tube, which comprises an inner tube and a fixing portion sleeved on the outside of the inner tube, wherein the rehydration expansion multiple of the inner tube is greater than the rehydration expansion multiple of the fixing portion.

[0007] The rehydration expansion multiple refers to the volume change rate compared with the initial volume when the gel is placed in water at room temperature (25°C ± 2°C) for 24 hours and the volume no longer changes after the gel has fully absorbed water.

[0008] Rehydration expansion ratio = (rehydration volume - initial volume) / initial volume × 100%.

[0009] Specifically, the rehydration expansion multiple is calculated according to formula (I):

[0010]

[0011] Among them, V1 is the volume of the gel after rehydration, and V0 is the initial volume of the gel in the dry state.

[0012] Preferably, the inner tube and the fixing part are both hydrogels, but due to different preparation processes, the inner tube and the fixing part have different crosslinking degrees, resulting in different rehydration expansion multiples. Based on this unique property, the inventors have produced a glaucoma drainage tube with unique efficacy. While maintaining smooth drainage of the slender inner tube, the fixing part can prevent the inner diameter of the inner tube from changing, effectively ensuring the stability of the inner tube lumen resistance.

[0013] Preferably, the difference between the rehydration expansion multiple of the inner tube and the rehydration expansion multiple of the fixing portion is 5% to 15%, for example: 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%.

[0014] Preferably, the rehydration expansion multiple of the inner tube is 45%-70%, for example: 45%, 50%, 55%, 60%, 65%, 70%.

[0015] Preferably, the inner tube is a channel for tear discharge, and its length after drying is 5 to 10 mm, its outer diameter is 130 to 170 μm, and its inner diameter is 40 to 60 μm.

[0016] Preferably, the rehydration expansion multiple of the fixing portion is 35%-60%, for example: 35%, 40%, 45%, 50%, 55%, 60%.

[0017] Preferably, the fixing portion is a barrier for the drainage tube to slide down to the anterior chamber, and has a length of 1 to 3 mm after drying and a radial span of 155-250 μm.

[0018] Preferably, there are one or more fixing parts.

[0019] Furthermore, the fixing portion is one and is arranged at one end of the inner tube.

[0020] Furthermore, there are two fixing parts, which are respectively arranged at two ends of the inner tube.

[0021] Since the rehydration expansion multiple of the inner tube is greater than that of the fixed part, after the inner tube and the fixed part are rehydrated, the inner tube and the fixed part become one. The fixed part can make the inner and outer diameters of the inner tube more stable.

[0022] Preferably, the fixing portion is a hollow tubular structure, which can be matched with the inner tube.

[0023] Preferably, the shape of the fixing portion includes but is not limited to cylindrical, truncated cone, fish fin, ellipsoid, and umbrella.

[0024] The fixing part is cylindrical, and its length after drying is 1 to 3 mm, its inner diameter is 135 to 185 μm, and its outer diameter is 155 to 205 μm.

[0025] The fixing part is in the shape of a truncated cone, with a length of 1 to 3 mm in a dry state, an inner diameter of 135 to 185 μm, an outer diameter of 155 to 205 μm at the top, and an outer diameter of 180 to 250 μm at the bottom.

[0026] The fixing part is ellipsoidal in shape, with a major axis length of 1 to 3 mm and a minor axis length of 155 to 250 μm in a dry state.

[0027] Preferably, the raw materials of the inner tube and the fixing part hydrogel are selected from any one of polyvinyl alcohol, gelatin, collagen or sodium hyaluronate.

[0028] Preferably, the raw material further comprises a cross-linking agent.

[0029] Furthermore, the cross-linking agent includes but is not limited to glutaraldehyde, butanediol glycidyl ether (BDDE), and divinyl sulfone (DVS).

[0030] In a second aspect, the utility model provides a glaucoma drainage tube implantation device, which comprises the above-mentioned glaucoma drainage tube and a sterile injection needle, wherein the glaucoma drainage tube is located inside the sterile injection needle.

[0031] In a third aspect, the utility model provides a method for preparing the glaucoma drainage tube according to the first aspect, comprising the following steps:

[0032] (1) Production of the inner tube and the fixing part. The tube body substrate is produced by casting, coating, weaving and electrospinning, and then the inner tube and the fixing part are produced by post-processing, such as cross-linking, cleaning, demoulding and cutting.

[0033] (2) After the inner tube and the fixing part are dried, they are placed in water to be fully soaked. Under the action of water, the fixing part is put on the outer side of the inner tube, combined, and then dried and fixed to obtain the gel-type glaucoma drainage tube.

[0034] Preferably, the raw material of the tube substrate in step (1) is selected from any one of polyvinyl alcohol, gelatin, collagen or sodium hyaluronate.

[0035] Preferably, the drying temperature in step (2) is room temperature to 70°C, more preferably 40 to 70°C, for example 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C.

[0036] Furthermore, the drying method is vacuum drying or forced air drying, more preferably vacuum drying.

[0037] Beneficial effects of the utility model:

[0038] 1. The utility model adopts a combination of a cylindrical inner tube and a fixing part to simply and effectively prepare a micron-level gel-type glaucoma drainage tube. After drying, the drainage tube is implanted under the conjunctiva through the anterior chamber through a disposable sterile injection needle. When it comes into contact with tissue fluid or tears, it will absorb water and swell. The fixing part increases the bonding force between the drainage tube and the tissue, which can effectively prevent the drainage tube from slipping after implantation.

[0039] Second, the rehydration expansion multiples of the inner tube and the fixed part of the utility model are different. The fixed part with a smaller rehydration expansion multiple is fixed on the outside of the inner tube, so that the size of the inner tube drainage channel remains stable, ensuring the stability of the tube cavity resistance, which is conducive to maintaining stable intraocular pressure after the drainage tube is implanted.

[0040] The dried gel of the utility model is in a dry state. The length is the axial span, which refers to the size of the gel in the axial direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is a schematic structural diagram of the glaucoma drainage tube of the utility model (the fixed part is cylindrical).

[0042] Figure 2 It is a schematic diagram of the structure of a glaucoma drainage tube with an ellipsoidal fixed portion.

[0043] Figure 3 It is a schematic diagram of the structure of a glaucoma drainage tube with a truncated cone-shaped fixed portion.

[0044] The reference numerals in the figure are as follows: 1-inner tube, 2-fixing part. DETAILED DESCRIPTION

[0045] The technical solution of the utility model is further described below in conjunction with the embodiments and drawings, and the advantages and features of the utility model will become clearer with the description. However, it should be understood that the embodiments are only exemplary and do not limit the scope of the utility model.

[0046] Example 1

[0047] (1) Manufacturing of the fixed part: Add 10 mL of a 10% (w / w) polyvinyl alcohol aqueous solution into a syringe, connect the catheter and the stainless steel needle, and install it on the electrospinning machine. Set the flow rate to 0.5 mL / h, the slide moving distance to 50 to 280 mm, the scanning speed to 20 mm / s, the rotation speed of the receiving device to 500 r / min, the distance between the needle and the stainless steel wire on the receiving device to 5 cm, the voltage to ±3.8 kV, and install a stainless steel wire with an outer diameter of 135 μm as the receiving device. Turn on the electrospinning machine. When the outer diameter of the fiber membrane on the stainless steel wire reaches 180 μm, remove the stainless steel wire, place the stainless steel wire covered with the fiber membrane in water vapor at 95°C for 30 minutes, and then soak it in a 20% sodium hydroxide solution containing 3% BDDE at 60°C for cross-linking. After cross-linking, remove the stainless steel wire, soak it in water, and after vacuum drying at 60°C, obtain a fixed part with an outer diameter of 155 μm, an inner diameter of 135 μm, and an expansion multiple of 59%.

[0048] (2) Manufacturing of the inner tube: Referring to the manufacturing process of the fixed part, the stainless steel wire of the receiving device is replaced with a stainless steel wire with an outer diameter of 40 μm, and the electrospinning machine is turned on. When the outer diameter of the fiber membrane reaches 230 μm, the stainless steel wire is removed, and the stainless steel wire with the fiber membrane on the surface is placed in water vapor at 95°C for 30 minutes, and then immersed in a 20% sodium hydroxide solution containing 1% BDDE at 60°C for cross-linking. The remaining steps are the same as the manufacturing process of the fixed part, and an inner tube with an outer diameter of 130 μm, an inner diameter of 40 μm, and an expansion multiple of 70% is obtained.

[0049] (3) Assembly of drainage tube: Combine a fixed part with a length of 1.5 mm after drying and an inner tube with a length of 6 mm after drying. First, dry the inner tube and the fixed part at room temperature for 30 minutes, then soak the inner tube and the fixed part in water to fully soak them. Under the action of water, put the fixed part on the outer end of the inner tube. Utilizing the different expansion multiples of the two, the fixed part with a lower expansion multiple can be stably fixed on the outside of the inner tube to form a combined gel-type drainage tube. Then, place the combined drainage tube in a vacuum drying oven at a temperature of 60°C. After drying for 2 hours, use tweezers to pick it up and put it into a disposable sterile injection needle.

[0050] Example 2

[0051] (1) Manufacturing of the fixed part: Add 10 mL of 15% (w / w) gelatin aqueous solution into the syringe, connect the catheter and the stainless steel needle, install it on the electrospinning machine, set the flow rate to 0.5 mL / h, the sliding table moving distance to 50-280 mm, the scanning speed to 20 mm / s, the speed of the receiving device to 500 r / min, the distance between the needle and the stainless steel wire on the receiving device to 5 cm, the voltage to ±3.8 kV, and install a stainless steel wire with an outer diameter of 135 μm as the receiving device. Turn on the electrospinning machine, when the outer diameter of the fiber membrane on the stainless steel wire reaches 180 μm, remove the stainless steel wire, place the stainless steel wire with the fiber membrane on the surface in water vapor at 60°C for 30 minutes, and then soak it in a 20% glutaraldehyde aqueous solution at 40°C for cross-linking. After cross-linking, remove the stainless steel wire, soak it in water, and after vacuum drying at 30°C, obtain a fixed part with an outer diameter of 155 μm, an inner diameter of 135 μm, and an expansion multiple of 52%.

[0052] (2) Manufacturing of the inner tube: Referring to the manufacturing process of the fixed part, the stainless steel wire of the receiving device is replaced with a stainless steel wire with an outer diameter of 60 μm, and the electrospinning machine is turned on. When the outer diameter of the fiber membrane on the stainless steel wire reaches 210 μm, the stainless steel wire is removed, and the stainless steel wire with the fiber membrane on the surface is placed in water vapor at 60°C for 30 minutes, and then immersed in a 10% glutaraldehyde aqueous solution at 40°C for cross-linking. The remaining steps are the same as the manufacturing process of the fixed part, and an inner tube with an outer diameter of 130 μm, an inner diameter of 60 μm, and an expansion multiple of 60% is obtained.

[0053] (3) Assembly of drainage tube: Combine two fixed parts with a length of 2 mm after drying and one inner tube with a length of 10 mm after drying. First, dry the inner tube and the fixed part at room temperature for 30 minutes, then soak the inner tube and the fixed part in water to fully soak them. Under the action of water, the two fixed parts are respectively put on the two ends of the outer side of the inner tube. The fixed part with a lower expansion multiple can be stably fixed on the outside of the inner tube to form a combined gel-type drainage tube. Then, place the combined drainage tube in a vacuum drying oven at a temperature of 30°C. After drying for 5 hours, use tweezers to pick it up and put it into a disposable sterile injection needle.

[0054] Example 3

[0055] (1) Manufacturing of the fixed part: Add 10 mL of 10% (w / w) sodium hyaluronate aqueous solution into the syringe, connect the catheter and the stainless steel needle, install it on the electrospinning machine, set the flow rate to 0.5 mL / h, the slide moving distance to 50-280 mm, the scanning speed to 20 mm / s, the rotation speed of the receiving device to 500 r / min, the distance between the needle and the stainless steel wire on the receiving device to 5 cm, the voltage to ±5.0 kV, and install a stainless steel wire with an outer diameter of 185 μm as the receiving device. Turn on the electrospinning machine. When the outer diameter of the fiber membrane on the stainless steel wire reaches 230 μm, remove the stainless steel wire, place the stainless steel wire covered with the fiber membrane in water vapor at 30°C for 30 minutes, and then soak it in a 20% sodium hydroxide solution containing 8% BDDE at 25°C for cross-linking. After cross-linking, remove the stainless steel wire, soak it in water, and after vacuum drying at 30°C, obtain a fixed part with an outer diameter of 205 μm, an inner diameter of 185 μm, and an expansion multiple of 35%.

[0056] (2) Manufacturing of the inner tube: Referring to the manufacturing process of the fixed part, the stainless steel wire of the receiving device is replaced with a stainless steel wire with an outer diameter of 60 μm, and the electrospinning machine is turned on. When the outer diameter of the fiber membrane on the stainless steel wire reaches 290 μm, the stainless steel wire is removed, and the stainless steel wire with the fiber membrane on the surface is placed in water vapor at 30°C for 30 minutes, and then immersed in a 20% sodium hydroxide solution containing 5% BDDE at 25°C for cross-linking. The remaining steps are the same as the manufacturing process of the fixed part, and an inner tube with an outer diameter of 170 μm, an inner diameter of 60 μm, and an expansion multiple of 48% is obtained.

[0057] (3) Assembly of drainage tube: Combine a fixed part with a length of 2.5 mm after drying and an inner tube with a length of 10 mm after drying. First, dry the inner tube and the fixed part at room temperature for 30 minutes, then soak the inner tube and the fixed part in water to fully soak them. Under the action of water, put the fixed part on the outer end of the inner tube. The fixed part with a lower expansion multiple can be stably fixed on the outside of the inner tube to form a combined gel-type drainage tube. Then place the combined drainage tube in a vacuum drying oven at a temperature of 30°C. After drying for 5 hours, use tweezers to pick it up and put it into a disposable sterile injection needle.

[0058] Example 4

[0059] (1) Preparation of the fixed part: Take 3 g of collagen, dissolve it in 100 mL of acetic acid solution, add 0.1 g of glutaraldehyde and stir evenly, inject it into a stainless steel mold (the mold is a hollow truncated cone mold with an inner diameter of 135 μm, a top of the truncated cone outer diameter of 155 μm, a bottom of the truncated cone outer diameter of 180 μm, and a height of 1.5 mm), place it at 37°C overnight, take it out, freeze it at -70°C for 4 hours, and dry it at 0°C for 24 hours to obtain a fixed part with an expansion multiple of 43%.

[0060] (2) Preparation of inner tube: 3 g of collagen was dissolved in 100 mL of acetic acid solution, and 0.03 g of glutaraldehyde was added thereto and stirred evenly. The mixture was injected into a ring-shaped stainless steel mold (the mold was a ring-shaped mold with an inner diameter of 40 μm, an outer diameter of 130 μm, and a height of 8 mm). The mixture was placed at 37°C overnight, then taken out, frozen at -70°C for 4 h, and dried at 0°C for 24 h to obtain an inner tube with an expansion multiple of 51%.

[0061] (3) Assembly of the drainage tube: The same manufacturing method as the drainage tube assembly in Example 1 is used and the tube is placed in a disposable sterile injection needle.

[0062] Example 5

[0063] (1) Preparation of the fixed part: Take 10 g of gelatin, dissolve it in 100 mL of water, add 0.1 g of glutaraldehyde and stir evenly, inject it into an ellipsoidal stainless steel mold (the mold is an ellipsoidal assemblable mold with a through hole, wherein the inner diameter of the through hole is 190 μm, the major axis of the ellipsoid is 2 mm, and the minor axis is 200 μm). After standing at 37°C overnight, remove the mold and take it out, freeze it at -70°C for 4 h, and dry it at 0°C for 24 h to obtain a fixed part with an expansion multiple of 47%.

[0064] (2) Preparation of inner tube: 10 g of gelatin was dissolved in 100 mL of water, and 0.03 g of glutaraldehyde was added thereto and stirred evenly. The mixture was injected into a ring-shaped stainless steel mold (the mold was a ring-shaped mold with an inner diameter of 50 μm, an outer diameter of 170 μm, and a height of 8 mm). The mold was placed at 37°C overnight, then taken out, frozen at -70°C for 4 h, and dried at 0°C for 24 h to obtain an inner tube with an expansion multiple of 58%.

[0065] (3) Assembly of the drainage tube: The same manufacturing method as the drainage tube assembly in Example 1 is used and the tube is placed in a disposable sterile injection needle.

[0066] Comparative Example 1

[0067] Add 10mL of 10% (w / w) polyvinyl alcohol aqueous solution to the syringe, connect the catheter and the stainless steel needle, install it on the electrospinning machine, set the flow rate to 0.5mL / h, the sliding table moving distance to 50-280mm, the scanning speed to 20mm / s, the speed of the receiving device to 500r / min, the distance between the needle and the stainless steel wire on the receiving device to 5cm, the voltage to ±3.8kv, and install a stainless steel wire with an outer diameter of 40μm as the receiving device. Turn on the electrospinning machine, when the outer diameter of the fiber membrane on the stainless steel wire reaches 230μm, remove the stainless steel wire, place the stainless steel wire with the cellulose membrane on the surface in water vapor at 95℃ for 30min, and then soak it in a 20% sodium hydroxide solution containing 1% BDDE at 60℃ for cross-linking, remove the stainless steel wire after cross-linking, soak it in water, and after vacuum drying at 60℃, obtain a drainage tube with an outer diameter of 130μm and an inner diameter of 40μm.

[0068] The drainage tube was dried at room temperature for 30 minutes, then immersed in water until the tube was filled with water. The tube was taken out and placed in a vacuum drying oven set at 60°C. After drying for 2 hours, it was picked up with tweezers and placed in a disposable sterile injection needle.

[0069] Performance Test Example 1: Testing of the in vitro pull-out force of glaucoma drainage tubes

[0070] After the samples in Examples 1 to 5 and Comparative Example 1 were inserted into the pig's eye and the silicone tube, the needle was withdrawn, and the drainage tube was left in the silicone tube and the needle was pulled out. The pig's eye and the silicone tube with the drainage tube inserted were fixed in a tensile machine, and then pulled out at a speed of 30 mm / min. The maximum pull-out force was measured using the UTM6202 electronic universal tensile testing machine of Shenzhen Sansi Zongheng Technology Co., Ltd. The greater the pull-out force, the greater the bonding force between the drainage tube and the tissue, and the less likely it is to slip off. The sample test results are shown in Table 1.

[0071] Table 1 Maximum pull-out force test results of samples

[0072]

[0073]

[0074] It can be seen from Table 1 that when the drainage tube is implanted in the pig's eye for a pull-out test, the maximum pull-out force of Examples 1 to 5 is significantly improved compared with Comparative Example 1. Compared with Comparative Example 1 (0.0024N) made of the same polyvinyl alcohol material, the maximum pull-out average force of the drainage tube of Example 1 can be increased to 0.0033N, with an increase of 37.5%. This indicates that the setting of the fixing part has an effect of improving the pull-out force of the drainage tube after implantation.

[0075] At the same time, when the drainage tube is implanted with a higher density silicone tube, the maximum pull-out force of Examples 1 to 5 is increased by 47.1%, 79.4%, 111.8%, 102%, and 110% respectively compared with Comparative Example 1. This also shows that the fixing part has an effect of improving the pull-out force of the drainage tube after implantation. Therefore, the in vitro pull-out test shows that the structure of the fixing part of the present application helps to improve the stability of the product after implantation and prevent the displacement of the drainage tube.

[0076] Performance Test Example 2: Lumen Resistance Test of Glaucoma Drainage Tube

[0077] The samples in Examples 1 to 5 and Comparative Example 1 were respectively loaded into a 29G injection needle, and then the pressure sensor, the syringe and the 29G injection needle with a drainage tube were connected through a T-type connector, and then the syringe was installed on a micro-injection pump so that it was at the same water height as the pressure sensor and the injection needle to form a test system. The flow rate of the micro-injection pump was 2.5 μL / min, artificial tears were added to the syringe, and the lumen resistance of the drainage tube was tested under an environment of 37°C ± 2°C, and the lumen resistance values ​​at 0 days, 10 days, 30 days, 60 days and 90 days were recorded, respectively. The results are shown in Table 2.

[0078] Table 2 Lumen resistance test results of samples

[0079]

[0080] As can be seen from Table 2, the lumen resistance of Examples 1 to 5 is relatively stable within 90 days, with almost no significant changes, while the lumen resistance of Comparative Example 1 begins to decrease after 30 days, and after 90 days, the lumen resistance has dropped to 10.35 mmHg, with a decrease of nearly 3%. Compared with the drainage tube of Example 1 with the same polyvinyl alcohol, the lumen resistance change rate is as high as 10 times. According to the relationship between the inner diameter of the pipe and the lumen resistance of the Hagen-Poiseuille equation, it can be seen that this is caused by the change in the size of the inner diameter of the drainage tube. The drainage tube of Comparative Example 1 has no fixed part structure, so when it is in an artificial tear environment for a long time, the inner diameter size of the drainage tube changes greatly, the lumen resistance changes greatly, and it is unstable; while the combined drainage tube structure of Example 1 has a fixed part with a high degree of cross-linking and a small expansion multiple. Under its action, the inner tube size of Examples 1 to 5 can remain stable and uniform, and the lumen resistance is stable and has no significant changes. It shows that the fixed part structure provides a relatively stable lumen resistance for the inner tube, which is conducive to maintaining the stability of intraocular pressure.

[0081] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, and these simple modifications all belong to the protection scope of the present invention.

Claims

1. A gel-type glaucoma drainage tube, characterized in that: The drainage tube comprises an inner tube and a fixing part sleeved on the outside of the inner tube, the inner tube and the fixing part are both hydrogels, the rehydration expansion multiple of the inner tube is greater than the rehydration expansion multiple of the fixing part; the fixing part is one or more.

2. The gel-type glaucoma drainage tube according to claim 1, characterized in that: The difference between the rehydration expansion multiple of the inner tube and the rehydration expansion multiple of the fixing portion is 5% to 15%.

3. The gel-type glaucoma drainage tube according to claim 1 or 2, characterized in that: The rehydration expansion multiple of the inner tube is 45%-70%; the length of the inner tube after drying is 5-10 mm, the outer diameter is 130-170 μm, and the inner diameter is 40-60 μm.

4. The gel-type glaucoma drainage tube according to claim 1 or 2, characterized in that: The rehydration expansion multiple of the fixing part is 35%-60%; the length of the fixing part after drying is 1-3mm, and the radial span is 155-250μm.

5. The gel-type glaucoma drainage tube according to claim 1, characterized in that: The fixing portion is in a hollow tubular shape.

6. The gel-type glaucoma drainage tube according to claim 1, characterized in that: The fixing portion is in the shape of a cylinder, a truncated cone, a fish fin, an ellipsoid or an umbrella.

7. The gel-type glaucoma drainage tube according to claim 6, characterized in that: The fixing part is cylindrical, and its length after drying is 1 to 3 mm, its inner diameter is 135 to 185 μm, and its outer diameter is 155 to 205 μm.

8. The gel-type glaucoma drainage tube according to claim 6, characterized in that: The fixing part is truncated cone-shaped, with a length of 1 to 3 mm after drying, an inner diameter of 135 to 185 μm, an outer diameter of 155 to 205 μm at the top, and an outer diameter of 180 to 250 μm at the bottom; Alternatively, the fixing portion is ellipsoidal in shape, and after drying, the major axis length is 1 to 3 mm, and the minor axis length is 155 to 250 μm.

9. The gel-type glaucoma drainage tube according to any one of claims 1 to 8, characterized in that: The materials of the inner tube and the fixing part are polyvinyl alcohol, gelatin, collagen or sodium hyaluronate, and the materials of the inner tube and the fixing part are the same or different.

10. A gel-type glaucoma drainage tube implantation device, characterized in that: The implantation device comprises the gel-type glaucoma drainage tube according to any one of claims 1 to 9 and a sterile injection needle, wherein the gel-type glaucoma drainage tube is located inside the sterile injection needle.

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