WO2021071449A1

WO2021071449A1 - A test box for the testing of glaucoma drainage implant in an in-vitro experimental setup

Info

Publication number: WO2021071449A1
Application number: PCT/TR2019/051249
Authority: WO
Inventors: Emre KARA
Original assignee: Gaziantep Universitesi Rektorlugu
Priority date: 2019-10-10
Filing date: 2019-12-30
Publication date: 2021-04-15

Abstract

The invention relates to a three-layer test box that was developed for the sensitively and comparatively testing of glaucoma drainage implants in an in-vitro experimental setup and for obtaining accurate measurement values. In general, the test box according to the invention consists of a bottom layer (1) having two holes (2) near the center, through which the glaucoma drainage implant tube can enter, a middle layer (4) comprising a chamber (5) in which the glaucoma drainage implant is placed, and an upper layer (6) is of transparent material.

Description

A TEST BOX FOR THE TESTING OF GLAUCOMA DRAINAGE IMPLANT IN AN

IN-VITRO EXPERIMENTAL SETUP

Subject Matter of the Invention

The invention relates to a three-layer test box that was developed for the sensitively testing of glaucoma drainage implants in an in-vitro experimental setup.

State of the Art

Intraocular pressure is generated by a fluid called aqueous humor produced in the choroid of the eye. After produced the aqueous humor is secreted into the eye. There is a balance between the production and extraocular exit of this aqueous humor. This slightly altered pressure balance during the day causes to glaucoma

Glaucoma means that the intraocular pressure increases as a result of insufficient flow of intraocular fluid (aqueous humor) and this pressure leads to damage to the optic nerve.

In the surgical therapy of glaucoma, special implants are used which carry the aqueous humor out of the eye by providing an alternative route. Implants other than micro/mini invasive glaucoma drainage implants (Ahmed Glaucoma Valve, Molteno and Baerveldt implants, etc.), consists of various outlet plates attached to the end of a silicone elastomer tube with an inner diameter of 0.32 mm, an outer diameter of 0.64 mm and a length of 16 mm. The aqueous humor is discharged from the outlet plate placed in the episclera by passing through the tube placed in the anterior chamber of the eye and thereby reducing intraocular pressure. In the state of the art, there are some studies related the testing of glaucoma drainage implants in in-vitro experimental setup .

Examples of the state of the art include US5656026A Patent document. Aforesaid document relates to the examination of glaucoma drainage implants in an in-vitro experimental setup. In said experimental setup, the glaucoma drainage implant is fixed with the aid of a shelf in a container containing water or salt solution. In the first phase, the same liquid (water or salt solution) is present in the test liquid chamber and container. Then a colored test liquid is obtained with the aid of the dye added to the liquid chamber and the passage of this colored liquid through the glaucoma drainage implant is observed with the aid of a microscope. In the apparatus of aforesaid document, there is no special chamber for placing the glaucoma drainage implant and a controlled inlet and outlet port for measuring pressure values. Therefore, it is thought that the measured values may vary. Furthermore, it is thought that the presence of the glaucoma drainage implant in a container containing an aqueous or salt solution will prevent clear observation of the flow of the test fluid.

Another example may include the document "Micro Particle-Image- Velocimetry for characterization of a micro-mechanical valve in a glaucoma implant". Said document describes a system for characterizing the micromechanical valve in a glaucoma drainage implant. In the experimental setup of this document, the microstent having the valve structure to be characterized is placed in a special test box. The test box consists of two separate sections. While the outlet of liquid from microstent is located on the side where the pressure is low, inlet of liquid into microstent is located on the side where the pressure is high. Further, there is a window above the test box that allows observing the experiment. In the test box of aforesaid document, a chamber in which the glaucoma implant can be placed was unmentioned. Therefore, it is thought that the measured values may vary.

Test boxes generally used in the prior art for in-vitro experimental setups for testing glaucoma drainage implants consist of only a syringe tip, a glaucoma drainage implant attached to it, and a transparent box containing them. With these test boxes, it is intended to measure the pressure at the inlet. Therefore, there is no controlled box outlet to measure the outlet pressure. Furthermore, in this test boxes, it is not possible to measure only the pressure drop due to the glaucoma drainage implant. Pressure drop caused by syringe and random placement of glaucoma drainage implant leads to differences in pressure measurements.

To eliminate the above-mentioned drawbacks, it is intended to develop a test box for sensitively testing of the pressure drop provided by the glaucoma drainage implant in-vitro.

Detailed Description of the Invention

An object of the invention is to sensitively and comparatively testing of glaucoma drainage implants in an in-vitro experimental setting and to develop a test box to minimize measurement errors.

The invention generally belongs to the field of biomedical engineering where fluid mechanics and ophthalmology departments match up with.

The invention is generally a test box for testing a glaucoma drainage implant in an in-vitro environment, comprising:

- a first layer comprising holes (2) for entering the tube of the glaucoma drainage implant, - a second layer located above the first layer and comprising a chamber (5) for fixing the body of the glaucoma drainage implant.

An embodiment of the invention comprises a third layer located above the second layer and comprising a transparent material for monitoring flow in the glaucoma drainage implant.

In an embodiment of the invention, the holes (2) are located close to the center.

In an embodiment of the invention, there are two holes (2), namely inlet and outlet holes.

In an embodiment of the invention, the depth of the holes (2) which are presented at the first layer is 12 mm.

In an embodiment of the invention, the diameter of the holes (2) presented at the first layer is 0.32 mm.

In an embodiment of the invention, the chamber (5) has a circular structure .

In an embodiment of the invention, the second layer is modular.

In an embodiment of the invention, the third layer is of transparent material. Preferably it is glass.

In an embodiment of the invention, the layers are connected to each other by a fastener. Preferably, the layers have engagement holes (3) at their corners, wherein the layers are connected to each other by screw-nuts through these engagement holes (3). Preferably, the layers have four engagement holes (3). Preferably there is a gasket between the layers. In an embodiment of the invention, the first layer is referred to as the bottom layer (1); the second layer is referred to as the middle layer (4); the third layer is referred to as the upper layer (6).

Figure 1 illustrates the bottom layer (1) according to the invention. The bottom layer (1) is developed to be located under the other layers, at the bottom between the screw-nut by the four engagement holes (3) placed at the corners thereof(by threading) . After the two holes (2) close to the center come to a depth of 12 mm, it reaches the middle layer (4) through holes (2) of 0.32 mm through which the tested glaucoma drainage implant tube can enter.

Figure 2 illustrates the middle layer (4) according to the invention. As in the bottom layer (1), in the middle layer (4) which is placed between bottom layer (1) and upper layer (6) with the screw-nut engagement holes (3) at the corners thereof, there is the glaucoma drainage implant. By means of one of the holes (2) in the bottom layer (1), a fluid passes through the tubing portion of the tested implant and discharges from the outlet plate of the implant in the annular chamber (5) to the other hole (2). Aqueous humor-like BSS solution (Balanced Salt Solution) is used as said fluid.

Figure 3 illustrates the upper layer (6). As in other layers, the upper layer (6), which is fixed by means of screw-nut engagement holes (3) at the corners thereof, is of a transparent material. Thus, the flow under the microscope can be visually tested. Any sealing problems or bubble formation can also be observed and understood from the upper layer (6). If necessary, a gasket may be placed/disposed between these layers. An embodiment of the invention is provided in Figure 4. Accordingly, the test box consists essentially of a bottom layer (1) having two holes (2) near the center, through which the glaucoma drainage implant tube can enter, a middle layer (4) comprising a chamber (5) in which the glaucoma drainage implant is placed, and an upper layer (6) of transparent material.

In an embodiment of the invention, the bottom layer (1), the middle layer (4) and the upper layer (6) are joined by means of screw-nut engagement holes (3). Preferably, the gasket is provided between the bottom layer (1), the middle layer (4) and the upper layer (6).

Thanks to the developed invention, the chamber (5), where the glaucoma drainage implant is fully fitted, prevents variable measurement values from occurring. The entrance and exit to/from the box according to the invention can be made imperviously through holes (2) of the same diameter. Sealing is provided by using "Tube Fitting with Ferrule" method. Thanks to the test box according to the invention consisting of three layers and upper layer (6) being transparent, it is understood how the implant placed between them works exactly and it is provided to easily monitor the flow through it. Thanks to the modularity of the middle layer (4) of the test box according to the invention, different configurations are possible after the test.

Description of the Figures

Figure-1 The view of the bottom layer of the test box structure according to the invention from different angles

Figure-2 The view of the middle layer of the test box structure according to the invention from different angles

Figure-3 The view of the upper layer of the test box structure according to the invention from different angles

Figure-4 Perspective view of the test box according to the invention Description of Reference Numbers in Figures

1. Bottom layer

2 . Hole 3. Engagement hole

4. Middle layer

5 . Chamber

6. Upper layer

Claims

1. A test box for testing a glaucoma drainage implant in an in-vitro environment, characterized in that comprising;

- a first layer comprising holes (2) for entering the tube of the glaucoma drainage implant,

- a second layer in which positioned above the first layer and comprising a chamber (5) for fixing the body of the glaucoma drainage implant.

2. The test box according to Claim 1, comprising a third layer which is located above the second layer and contains a transparent material for monitoring the flow in the glaucoma drainage implant.

3. The test box according to claim 1, wherein the holes (2) are located close to the center.

4. The test box according to claim 1 or 3, wherein the holes (2) are two, namely inlet and outlet holes.

5. The test box according to claim 1 or 3, wherein the depths of the holes (2) are 12 mm.

6. The test box according to claim 1 or 3, wherein the diameters of the holes (2) are 0.32 mm.

7. The test box according to claim 1, wherein the second layer is modular.

8. The test box according to claim 1, wherein the chamber (5) has a circular structure.

9. The test box according to claim 1 or 2, wherein the layers are connected to each other by screw-nuts engagement holes (3).

10 . The test box according to claim 9, wherein it comprises a gasket between the layers.