Device for influencing intraocular pressure

Abstract

Device (1) for influencing intraocular pressure (IOP) with a controllable drainage device (2) which is suitable and intended for draining fluid from at least one area of ​​the eye (50), characterized in that the device (1) has a first sensor device (4) which detects at least one first value (W1) characteristic of the intraocular pressure (IOP), and a second sensor device (6) which detects at least one second value (W2) characteristic of a pressure acting on the eye, and a control device (8) which controls the drainage device (2) at least temporarily taking into account the first characteristic value (W1) and the second characteristic value (W2), wherein the second characteristic value (W2) is characteristic of an intracranial pressure and / or a cerebrospinal pressure.

Description

The present invention relates to a device for influencing intraocular pressure. The invention is described with reference to glaucoma, but it is noted that the device according to the invention can also be used in other areas. It is known from the prior art that intraocular pressure (IOP) is important in glaucoma. More recently, however, it has also been determined that, for example, while elevated IOP is an important risk factor in the development of glaucoma, it is not present in all forms of glaucoma. Furthermore, elevated IOP does not necessarily always increase the risk of developing the disease. It has been found that, in addition to intraocular pressure, the so-called intracranial pressure (ICP) also plays a role.The cerebrospinal fluid (CSF) pressure is important, and in particular the ratio of this pressure to the intraocular pressure. Furthermore, procedures for lowering intraocular pressure (IOP) are known in the field of glaucoma therapy. For example, it is known to use shunts or stents, which allow fluid to drain from the eye. Current glaucoma therapies (e.g., for narrow-angle and open-angle glaucoma) are based solely on lowering the IOP or adjusting it to statistically determined normal ranges (e.g., less than 15–20 mmHg). It is also known to observe glaucoma progression (normal-tension glaucoma), for example, by detecting a decrease in the thickness of the retinal nerve fiber layer. In these cases, the pressure can only be lowered further, for example, to 8–10 mmHg. In addition, surgical procedures (iridectomies, trabeculectomies) or the aforementioned implants (shunts or stents) are used to improve natural drainage pathways. In particular, trabecular or uveoscleral drainage can be created. Furthermore, it is also known that entirely new drainage pathways can be created, for example, from the anterior chamber into the suprachoroidal or subconjunctival space, or even onto the ocular surface. For example, unregulated shunts are known from the prior art, which have a constant outflow resistance, so that the pressure gradient achieved depends on the current aqueous humor flow and can therefore fluctuate throughout the day. Devices and methods of this kind are also known, for example, from patent application US 2015 / 0257931 A1 and the article "JONAS, JB; WANG, N.: Association between arterial blood pressure, cerebrospinal fluid pressure and intraocular pressure in the pathophysiology of optic nerve head diseases. In: Clinical and Experimental Ophthalmology, Vol. 40, 2012, e233 - e234." The present invention is therefore based on the objective of achieving a more favorable normalization or adjustment of intraocular pressure differences. This objective is achieved according to the invention by the subject matter of the independent claim. Advantageous embodiments and further developments are the subject of the dependent claims. An inventive device for influencing intraocular pressure comprises a controllable drainage device which is suitable and intended for draining fluid from the eye or from a region of the eye. According to the invention, the device comprises a first sensor device which detects at least one value characteristic of the intraocular pressure of that eye, a second sensor device which detects at least one value characteristic of a pressure acting on the eye, and a control device which controls the drainage device taking into account the first and second values. It is therefore proposed according to the invention that (at least) two characteristic values ​​are used to control a corresponding drainage device. Control taking into account the first and second values ​​means that these two values ​​can be used either directly or indirectly, for example by determining a result value that considers these two values, such as, as mentioned in more detail below, a difference or a ratio, and using this result value for control. In particular, the control device controls the drainage device with regard to a flow cross-section and / or a quantity of fluid to be drained from the eye. Preferably, at least one of the two sensor devices is arranged intracranially. Preferably, at least the first sensor device is arranged intracranially. Preferably, both sensor devices are arranged intracranially. However, it would also be possible for at least one of the two sensor devices, and in particular the second sensor device, to be arranged extracranially. Preferably, the drainage device is also arranged intracranially. For example, it is possible to adjust the pressure difference between the IOP and the ICP, or to control the system based on this pressure difference. The invention is therefore also based on the consideration that if the difference or ratio deviates from the normal range, it can be assumed that this can lead not only to mechanical stress on the optic nerve, but also to deficits in axonal transport, i.e., in the supply of nutrients to the nerves, which can lead to atrophy and even nerve death. It is therefore proposed that the drainage device be controlled specifically based on two parameters. In a further advantageous embodiment, the device includes a limiting device that prevents the pressure drop from falling below a certain minimum value. In another preferred embodiment, the control device is designed to also control the quantity and / or the flow cross-section of the fluid drained from the eye. It would be possible, for example, to control and / or regulate the flow resistance. According to the invention, the second characteristic value is characteristic of an intracranial pressure and / or a cerebrospinal pressure. As mentioned above, these two values ​​are particularly related to each other. It would also be possible to determine a quantity related to these values, such as a dynamic characteristic of the optic nerve. In a further advantageous embodiment, the device includes a processor which determines a result value taking into account the first characteristic value and the second characteristic value, with the control unit controlling the discharge device based on this result value. Advantageously, this result value is used as a control variable, which, for example, regulates the flow rate of the discharge device. This flow rate, in turn, can be a manipulated variable of the control system. This result is particularly preferred as a difference or ratio between the first characteristic value and the second characteristic value. Generally, the lamina cribrosa separates the two pressurized regions, and the pressure drop occurring across this lamina cribrosa is also referred to as the translaminar pressure difference. In a further preferred embodiment, the two said sensor devices are arranged separately from each other. In a further preferred embodiment, a communication link exists between at least one sensor device and the control device, enabling data exchange. This communication link is preferably selected from a group of communication links, including radio links, wired links, sound links (especially ultrasound links), and optical or light-based communication links. In a preferred embodiment, the respective communication signal could be transmitted as a modulated sound signal. In the case of an optical link, infrared light of a predetermined wavelength could be transmitted through the skull and / or the optic nerve. Modulated signals via the nerve pathway, modulated sound signals, or the like would also be conceivable. Different communication connections would also be conceivable. In a preferred embodiment, the first sensor device is designed as a unit with the control device. Preferably, communication connections between the first sensor device and the control device can be provided as cable or wired connections. In a further advantageous embodiment, the device includes a processing unit for generating differences and / or ratios between the measured values. As mentioned above, the measured values ​​are in particular pressure values, and the sensor devices are preferably pressure sensor devices. In another preferred embodiment, the control device is designed such that it controls the drainage device, at least temporarily, based on only one of the two measured values. For example, the control device can temporarily control the drainage device using only the measured value for intraocular pressure. The measurement of the second characteristic value can be performed at regular, predetermined intervals, and a result or control can be modified based on this measurement. The first sensor device can also perform measurements at predetermined intervals. Preferably, the first sensor device performs measurements more frequently than the second sensor device. Preferably, the control device is designed to continuously adjust the pressure difference between IOP and ICP. This allows the ICP to be continuously or at specific intervals measured by the second sensor device located in or on the skull. As mentioned above, the IOP can be measured in or on the eye using the first sensor device. The signals from these sensor devices, which are particularly preferably pressure sensors, are transmitted, preferably processed, and used, in particular, to control the drainage device, which in this case is an element that modifies (generally lowers) the IOP. In particular, it is possible that an adjustable drainage device (shunt) is provided to achieve a desired pressure difference between IOP and ICP. The drainage device can be designed in various ways. For example, the discharge device could include an osmotically actuated fluid valve. Such a valve can have an inlet channel for a fluid and an outlet channel that is connected to the inlet channel via an opening. Such a valve is described, for example, in US 2014 / 0172090 A1. Alternatively, it would also be possible to provide a so-called shunt that can be inserted into Schlemm's canal. This shunt can include a Venturi element to control the fluid flow from an inlet to an outlet. Furthermore, the drainage device can preferably include a pump for aspirating fluid. In a preferred embodiment, this pump can be implantable. The drainage device may further include a valve element for controlling the flow of a liquid. The control device may preferably also control this valve element. In a preferred embodiment, the drainage device may also include a sensing device for detecting the position of such a valve. Another usable pumping system for draining fluid from the eye is described, for example, in US 6,589,198 B1. Furthermore, the discharge device may include elements that regulate the flow of liquids, such as orifices. For example, an orifice with a variable diameter could be provided. Alternatively, orifices that are movable relative to each other could be provided to regulate the flow. In a further advantageous embodiment, the discharge device includes a drive unit for controlling the flow rate. This drive unit can be, for example, a servo motor, or more generally, an electric motor. Piezoelectric motors or piezoelectric actuators can also be used. In a further preferred embodiment, the first sensor device and / or the second sensor device and / or the drainage device comprises an electrically operated implant, and in particular an implant that is inserted or can be inserted into the eye. Furthermore, a transmitting device and / or a transmitter can be used, which can, for example, be placed outside the head. This transmitting device emits an electromagnetic field that is strong enough to supply the implant with electrical energy. The implant can also include a shunt element—which can be placed, in particular, within this electric field—that is also energized by this electric field and can thus be operated. In a further advantageous embodiment, the drainage device comprises a shunt and / or a stent. A shunt typically forms an artificial drainage connection for removing fluid, while a stent is used to modify the flow cross-section of a naturally occurring flow connection. The device preferably includes a storage device in which reference values, in particular reference values ​​for the aforementioned result value, for example, a difference between IOP and ICP, are stored. The controllable discharge device can be controlled accordingly such that a specific target value for this result value, i.e., the difference between IOP and ICP, is reached. In a preferred embodiment, the sensor devices are designed to detect at least one change in intraocular pressure (IOP) and / or intracranial pressure (ICP) and preferably use this information to control a variable of the pressure-regulating element or the drainage device. For example, the control behavior can be designed as a patient-specific, dynamically learning system, or as a model-based system for individually and optimally adjusting the pressure, for example, to minimize control errors. This allows, for instance, the consideration of fluctuations in aqueous humor production throughout the day, particularly when the drainage device has a limited capacity. In this way, the pressure reduction could begin even before the increase in aqueous humor production, which typically occurs in the morning. In a further advantageous embodiment, the device, and in particular the control unit, includes a storage device suitable and intended for storing measurement and / or operating parameters. It is particularly possible to store personal parameters or factors, such as the person's age, gender, environmental factors, and the like. Preferably, the processor or control unit also controls the drainage device taking these parameters into account. Since the effects of unfavorable pressure conditions can also depend on anatomical factors (such as the thickness of the lamina cribrosa) or other personal factors (age, ethnicity, medical or therapeutic history, medication), the possibility of considering these personal factors in the processing unit or control device is preferred. In addition, it is also possible to consider other factors or environmental factors, such as the time of day, the circadian rhythm, and the like. In a further advantageous embodiment, the control device has at least one control output for controlling a drug depot. Preferably, the control device also has a second control output for controlling a second drug depot. This means that at least one, and preferably two, additional drug dosages can be controlled. In particular, this allows for the support of pressure management through controlled drug delivery from preferred drug depot implants. For example, prostaglandins can be administered to improve aqueous humor outflow through ocular tissue, or beta-blockers can be administered to suppress aqueous humor production in the ciliary body. The control device is preferably designed and intended to consider a treatment priority sequence in order to minimize side effects. For example, regulation via the outflow mechanism can be addressed first, followed by the delivery of prostaglandins, and finally beta-blockers.It is also possible to use ICP-altering elements and medications to achieve or support the difference between IOP and ICP, i.e., the pressure differential setting. As mentioned above, it is possible to lower the pressure to a minimum level, for example, 8 mmHg. It would also be possible to initially take individual measurements of absolute ICP (CSF) and IOP values ​​and then only record changes using the sensor devices. Alternatively, ICP or ICP-related parameters could be measured only occasionally (e.g., daily), while IOP values ​​are determined more frequently, for example, every second, minute, or hour. In a further advantageous embodiment, the IOP sensor device and preferably also the pressure control unit (i.e., in particular the discharge device) are implemented in a common module or a common unit and preferably also operate in the event of a breakdown of the communication connection with the second sensor device. In a further advantageous embodiment, the device includes an additional sensor assembly that detects measurements characteristic of the user's position, orientation, and / or movement, particularly of the user's skull. It has been shown that such parameters can also influence intraocular pressure. This additional sensor assembly can be arranged both intracranially and extracranially. Furthermore, other sensor assemblies can be provided that detect values ​​such as ambient pressure or temperature. Preferably, this additional sensor device is selected from a group of sensor devices that includes tilt sensors, motion sensors, accelerometers, and the like. Furthermore, a break-stop device could preferably be provided which interrupts the measurement of IOP and / or ICP depending on the data output by the additional measuring device. For example, a measurement of IOP or ICP could be interrupted at certain head tilts. For example, it is possible to take into account the head position and / or the body's acceleration, as these values ​​can influence the pressure conditions in the skull and eye. Knowing this allows for better regulation and control of these pressure conditions. As an alternative to direct ICP measurement, the dynamics of the optic nerve can also be observed, for example, by monitoring the pulsation of vessels at the optic nerve head (ONH). This observation allows for inferences about the magnitude of the ICP relative to the IOP, and this relationship can then be used for pressure regulation. Vascular and tissue pulsations can be detected using methods such as OCT (optical coherence tomography), confocal scanners, or ultrasound. In a further preferred embodiment, this device includes an energy storage device that supplies at least one of the aforementioned units, and in particular the drainage device, with electrical energy. The energy storage medium can be one that derives its energy from an electrolyte and / or a substance that is at least partially derived from the body. As mentioned above, however, energy sources can also be provided that supply the sensor device and / or the drainage device with energy from an external source. In a further advantageous embodiment, the control device is designed as a relay station and / or external communication interface. This can preferably issue control commands to the discharge device. In a further preferred embodiment, the control device is designed to enable bidirectional (data) communication with at least one sensor device, and preferably with both sensor devices. Preferably, the control device is also designed to enable bidirectional (data) communication with the discharge device. This allows control commands to be issued from the control device to the discharge device. Conversely, data, such as data characteristic of the position of valves or the like, can preferably also be issued from the discharge device to the control device. In another preferred embodiment, the control device can also include a timer. This allows, for example, the timing of the individual values ​​measured by the sensor devices to be controlled. More generally, the control device can be configured to issue commands to the sensor devices, which in turn cause the sensor devices to perform measurements. This allows, in particular, the transmission of measurement data from the sensor(s) to the control unit. Conversely, data and / or commands can preferably also be transmitted from the control unit to the sensor(s). The present invention further relates to a method for influencing intraocular pressure. In this method, a fluid is drained from at least one area of ​​the eye at least temporarily by means of a controllable drainage device. According to the invention, a first sensor device at least temporarily detects at least one first value characteristic of the intraocular pressure (of that eye), and a second sensor device detects at least one second value characteristic of a pressure acting on the eye. Furthermore, a control device controls the drainage device at least temporarily, taking into account the first characteristic value and the second characteristic value. In a further advantageous method, at least one sensor device, and in particular the second sensor device, communicates wirelessly with the control device. In a further preferred method, at least one of the characteristic values ​​is a pressure value. Preferably, the first and second sensor devices measure the characteristic values ​​at predetermined time intervals. These time intervals preferably differ from each other. Preferably, the second sensor device measures the second value at longer time intervals and / or less frequently than the first sensor device. In a further preferred method, the control device controls at least one drug delivery. Particularly preferably, the control device also controls the drug delivery depending on at least one of the two measured values. The invention is explained in more detail below with reference to the drawing by way of example. In the drawing: Fig. 1 shows a representation of a human eye to illustrate the problem underlying the invention; Fig. 2 shows a block diagram representation of a first embodiment of a device according to the invention; Fig. 3 shows a block diagram representation of a second embodiment of a device according to the invention; and Fig. 4 shows a representation of an alternative device according to the invention. Fig. 1 shows a schematic representation of a human eye 50. Reference numeral 52 refers to the iris of the eye, and reference numeral 54 to the cornea. Reference numeral 56 denotes the lens, and reference numeral 58 the pupil. Reference numeral 62 denotes the retina, and reference numeral 64 the optic nerve. As indicated by the arrow IOP, the intraocular pressure acts outwards from the eyeball. Furthermore, as shown by the second arrow ICP, the cerebrospinal pressure also acts inwards. The pressure difference ICP - IOP occurs in the area indicated by the dashed lines. This is a particularly relevant measurement. The reference numeral CSF refers to the cerebrospinal fluid. It is known to drain aqueous humor using drainage devices (not shown in Fig. 1), thereby reducing the intraocular pressure IOP. Fig. 2 shows a block diagram representation of a first embodiment of the device 1 according to the invention. This device 1 has a drainage device 2, which is controllable and serves to drain fluid from the eye 50. This drainage device 2 is controllable and preferably adjustable, whereby in particular the flow rate of the fluid to be drained from the eye 50 is adjustable. Reference numeral 8 designates a control device which serves to control or regulate the discharge device 2. In particular, the control device 8 can regulate the flow rate caused by the discharge device 2. Reference numeral 4 identifies a first sensor device that acquires a measurement W1 characteristic of intraocular pressure (IOP) and outputs it to the control device 8. Reference numeral 6 identifies a second sensor device that outputs a measurement W2 to the control device 8, where, as mentioned above, this measurement W2 is a value for intracranial pressure and / or cerebrospinal pressure. As indicated by the arrows at W1 and W2, these measured values ​​W1 and W2 are provided to the control unit 8. The reference numeral 82 designates a processor unit which serves to determine a result value E from these two values ​​W1 and W2, in particular by means of a mathematical operation. This result value E could, for example, be a difference between the two values ​​W1 and W2, i.e., for example, a difference between the ICP and the IOP. Reference numeral 84 identifies a storage device, which is or may also be part of the control device 8 and in which, for example, person-specific data can be stored. A further processor device 86 determines a manipulated variable S from the result value E, which is supplied to the drainage device 2 so that it controls, in particular, the flow of ocular fluid accordingly. As mentioned above, it is possible, for example, that the control device 8 and the discharge device 2 are implemented as a single module. Furthermore, it would also be possible that the first sensor device 4 and the control device 8 are implemented as a single module. Similarly, the first sensor device 4 and the discharge device 2 could be implemented as a single module. Finally, it would also be possible that the first sensor device 4, the control device 8, and the discharge device 2 are implemented as a single module. Fig. 3 shows another block diagram-like representation of a second embodiment of the device according to the invention. Here again, the first sensor device 4 and the second sensor device 6 are shown, which transmit the respective values ​​W1 and W2 to the control device 8. In addition, a further sensor device 12 is provided, which transmits environmental values ​​U to the control device 8. These environmental values ​​can be, for example, acceleration values, inclination values, and the like; that is, in particular, values ​​that characterize the movements or positions of the user whose intraocular pressure is to be corrected. The storage device 84 can also transmit values ​​P, that is, personal values ​​of the user, to the control device 8, such as, as mentioned above, values ​​that characterize the user's age, ethnicity, or medical history.The control unit 8, and more precisely, for example, the processor unit 82 (not shown), processes these values ​​and, based on these values, also controls the discharge unit 2 via an output 80 by means of a manipulated variable S. The discharge unit 2, in turn, can have a sensor unit 22, which measures a manipulated variable or a position of the discharge unit 2 (in particular of an actuating element of this discharge unit) and, if necessary, also transmits these values ​​back to the control unit 8 for control. Reference numeral 94 designates a control output of the control unit 8, via which, for example, a signal S1 can be output to a first medication depot 14. Reference numeral 92 designates a second control output, via which, for example, a signal S2 can be output to a second medication depot 16. Based on these signals, these medication depots can dispense medication to the user, particularly in a predefined manner. Fig. 4 shows a further embodiment of a device 1 according to the invention. In this embodiment, an external communication interface or control unit 8 is provided. This is arranged, in particular, outside the user's head (extracranially), for example in a spectacle temple or in a head-mounted device (HMD). It is specifically provided that the control unit 8 communicates bidirectionally with the sensor units 4 and 6 as well as the drainage unit 2. The sensor units 4 and 6 as well as the drainage unit 2 are located intracranially, i.e., inside the head. The pressure of the discharge device 2 is regulated by the control device 8. Conversely, status information can be transmitted from the discharge device 2 to the control device 8 via the bidirectional connection. Furthermore, it would also be possible to measure certain values ​​non-invasively or from outside the skull. For example, a device could be used that is based on the principle that the intracranial pressure (ICP) correlates directly with the pressure within the central retinal vein in the eye. The applicant reserves the right to claim all features disclosed in the application documents as essential to the invention, provided they are novel individually or in combination compared to the prior art. It is further noted that the individual figures also describe features which may be advantageous on their own. A person skilled in the art will immediately recognize that a particular feature described in a figure may be advantageous even without incorporating other features from that figure. Furthermore, a person skilled in the art will recognize that advantages may also arise from a combination of several features shown in individual or different figures. Reference symbol list 1 First embodiment of a device according to the invention 2 Drainage device 4 First sensor device 6 Second sensor device 8 Control device 12 Further sensor device 14 First drug depot 16 Second drug depot 22 Sensor device of the drainage device 50 Human eye 52 Iris 54 Cornea 56 Lens 58 Pupil 62 Retina 64 Optic nerve 80 Output 82 Processor device 84 Storage device 86 Further processor device 92 Second control output 94 Control output E Result value IOP Intraocular pressure P Values ​​S Control variable S1 Signal S2 Signal U Ambient values ​​W1 Measured value W2 Measured value CSF Cerebrospinal fluid ICP Intracranial pressure

Claims

Device (1) for influencing intraocular pressure (IOP) with a controllable drainage device (2) which is suitable and intended for draining fluid from at least one area of ​​the eye (50), characterized in that the device (1) has a first sensor device (4) which detects at least one first value (W1) characteristic of the intraocular pressure (IOP), and a second sensor device (6) which detects at least one second value (W2) characteristic of a pressure acting on the eye, and a control device (8) which controls the drainage device (2) at least temporarily taking into account the first characteristic value (W1) and the second characteristic value (W2), wherein the second characteristic value (W2) is characteristic of an intracranial pressure and / or a cerebrospinal pressure. Device (1) according to claim 1, characterized in that the device (1) has a processor unit (82) which determines a result value (E) taking into account the first characteristic value (W1) and the second characteristic value (W2), and the control unit (8) controls the discharge unit (2) taking into account this result value (E). Device (1) according to claim 2, characterized in that this result value (E) is a difference or ratio between the first characteristic value (W1) and the second characteristic value (W2). Device (1) according to one of the preceding claims, characterized in that a communication link exists between at least one sensor device (4, 6) and the control device (8) and this communication link is preferably selected from a group of communication links which includes radio links, wired links, sound links, in particular ultrasound links, or light-based communication links. Device (1) according to one of the preceding claims, characterized in that the control device (8) controls the discharge device (2) at least also temporarily only taking into account one of the two measured values ​​(W1, W2). Device (1) according to one of the preceding claims, characterized in that the control device (8) has a storage device (84) which is suitable and intended for storing operating parameters. Device (1) according to one of the preceding claims, characterized in that the control device (8) has at least one control output (92, 94) for controlling a drug depot (14, 16). Device (1) according to one of the preceding claims, characterized in that the device (1) has a further sensor device (12) which detects measured values ​​which are characteristic of a position or orientation, in particular of the body or body parts of a person. Device (1) according to one of the preceding claims, characterized in that the drainage device (2) has a shunt and / or a stent. Method for influencing intraocular pressure (IOP), wherein a fluid is drained from at least one area of ​​the eye (50) at least temporarily by means of a controllable drainage device (2), characterized in that at least a first value (W1) characteristic of the intraocular pressure (IOP) is detected at least temporarily with a first sensor device (4), and at least a second value (W2) characteristic of a pressure acting on the eye (50) is detected at least temporarily with a second sensor device (6), and a control device (8) controls the drainage device (2) at least temporarily taking into account the first characteristic value (W1) and the second characteristic value (W2), wherein the second characteristic value (W2) is characteristic of an intracranial pressure and / or a cerebrospinal pressure.

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