RU2727036C1 - Method of treating open-angle glaucoma, device for implementation thereof and working tool - Google Patents

Abstract

FIELD: medicine.SUBSTANCE: group of inventions relates to ophthalmology. Method of treating the open-angle form of glaucoma by providing a watery outflow through the sclera in a projection of the ciliary body by a series of laser applications along its perimeter. Closed cavity is formed in the place of each specific application by means of the working tool, the pressure in which the pressure is less than the intraocular pressure inside the cavity. Laser radiation is directed. Intensity of the laser radiation reflected from the sclera is measured to determine its minimum and maximum values, when the ratio of the said values takes a value in range of 2.5–3.0, laser radiation is terminated and said sequence of operation is repeated in adjacent point of sclera along perimeter of ciliary body. Device comprises laser with working tool connected to it through optical waveguide. Laser through controller is connected by electric line to electronic unit and by one of two optical lines to optoelectronic unit, and through another optical line through reverse coupler to working tool, connected via reverse coupler to optoelectronic unit. Working tool is connected to the electronic unit by electric lines, and a switch is installed in the laser communication line with the controller. Working tool comprises housing accommodating metal tube accommodating optical waveguide having metalized inner layer with end surface contacting eyeball. At the end of the tube there is an elastic hemispherical suction cup having a metallized surface on its inner side, wherein metallized surfaces of waveguide and suction cups are connected via electric lines to contact sockets intended for connection to electronic unit of device.EFFECT: use of this group of inventions enables higher effectiveness and safety of treating open-angle glaucoma.5 cl, 9 dwg

Description

The group of inventions relates to ophthalmology, and more specifically, to a method for treating various stages of open-angle glaucoma, a device for its implementation and a working tool.

A large number of works have been devoted to methods of treatment by laser irradiation of biological tissues. Moreover, in medicine, in particular, in ophthalmology, the irradiation regime is mainly controlled visually by the doctor performing the operation on the patient's eyes and depends on his individual experience. This is possible in the case of laser action on the eye tissue, where the dose of laser energy absorbed in the tissue is precisely calculated. In this case, the previously calculated radiation dose should be adjusted taking into account the individual optical properties of patients. This adjustment is done empirically manually, and its effectiveness and safety depends on the experience of the ophthalmologist. This is how most laser eye surgeries are performed, including for various forms of glaucoma, starting with the method proposed by M.M. Krasnov. in 1970 (Copyright certificate for inventions for various forms of glaucoma in the USSR No. 313544, IPC, publ. (USSR).

In the case of routine operations, for example, during laser surgery, to change the refraction of the cornea "Lasik", the irradiation mode is controlled automatically by measuring the thickness of the corneal layer required for removal by laser ablation. At the same time, the irradiation mode, the energy dose are calculated using a computer, and then layer-by-layer keratoplasty is performed until the desired thickness is reached (ZIEMER S Femto LDV Z http://www.femtoldv.ru).

A control system for laser ablation of biological tissue is declared in US patent 5.107.516 Apparatus for controlled ablation by laser radiation, IPC A61B 18/20, publ. 04.21.1992. A control system for laser welding of biological tissues with scattered radiation feedback is presented in US patent 5334191 "Laser tissue welding control system" August 2, 1994 IPC A61B 18/20, publ. 02.08.1994.

In the treatment of glaucoma using diode contact trans-scleral cyclophotocoagulation (Yap-Veloso MI et al. J. Glaukoma. - 1998. - Vol.7. - No. 5. - P. 319-328.), The irradiation mode is set manually, and the intraocular pressure is carried out the next day after the operation by one of the known methods of tonometry.

Control of changes in tissue permeability at the point of its irradiation is carried out by the flow of intraocular fluid through the sclera (Avetisov S.E. et al. National Journal. Glaucoma. - 2015. - T14. - No. 2. - S. 5-15.) In a closed volume adjacent to the irradiated area. The possibility of enhancing the filtration of intraocular fluid through the sclera has been established (Bolshunov A.V. et al. Bulletin of Ophthalmology. - 2013. - T.129. - No. 1. - S. 46-53). A closed low-pressure volume is created using a suction cup, which is installed on the sclera in a place irradiated with laser radiation.

When carrying out a similar transscleral cyclophotocoagulation using a diode laser at a wavelength of 820 nm "Micro Pulse" manufactured by IRIDEX (http://www.iridex.com), a sequential point effect of laser micro-pulses on the sclera in the projection of the ciliary body is used to amplify uveal outflow of intraocular fluid, leading to a gradual decrease in intraocular pressure. Irradiation is carried out using a special instrument, the so-called. "G-probe", which is placed at an angle to the surface of the sclera. No diagnostics are performed during the irradiation process. Delayed tonometry is performed after laser therapy.

In the above methods of laser action on the eye tissue, the diagnosis of the state of the intraocular fluid is carried out after irradiation and does not allow determining the moment of the beginning of the intensification of the transscleral outflow of fluid, on which the intraocular pressure depends. It should be noted that prior to the proposed method of treating various stages of open-angle glaucoma, insito (in-situ) diagnostics of intraocular pressure during laser irradiation was not carried out. Feedback was not used in the control laser control systems during transscleral cyclophotocoagulation. Due to the lack of control of intraocular pressure during the operation, these methods are not able to ensure the effectiveness of laser exposure and the safety of the operation.

Closest to the proposed method is the method according to the patent RU 2463029 "Method for the treatment of resistant forms of open-angle glaucoma", IPC A61F 9/08, publ. 10.10.2011

In accordance with this method, applications are applied to the sclera in the projection of the ciliary body along the entire circumference of the sclera, with the formation of microchannels at the same distance from each other by means of contact action with laser radiation. This ensures the outflow of aqueous humor through the sclera and a drop in intraocular pressure.

The irradiation mode is selected on the basis of the average statistical parameters of increasing the permeability of the sclera for the uveal outflow of moisture, which provides a decrease in intraocular pressure due to the formation of microchannels in the sclera and increased filtration of the fluid. The irradiation process is controlled by an ophthalmologist and is selected on the basis of experimental data from a calculation performed for an average patient. Operational monitoring of intraocular pressure (IOP) in the treatment of glaucoma by this method is not carried out. The effectiveness of laser treatment is determined based on the patient's subjective data and IOP measurements after surgery

The disadvantages of this method is that IOP measurement during treatment is carried out immediately after tissue irradiation or after some time. The impossibility of controlling the current changes in the hydropermeability of the sclera and, as a result, a decrease in IOP during irradiation leads to a decrease in the effectiveness of laser treatment, and an overdose of irradiation makes the procedure unsafe.

The technical task of the proposed method is to ensure the current control of IOP by monitoring the hydropermeability of the sclera.

The technical result from the application of the method is to increase the efficiency and safety of treatment of various stages of open-angle glaucoma.

The solution of the technical problem and the achievement of a technical positive result is ensured by the fact that in the method of treating various stages (initial, developed or far advanced) of open-angle glaucoma by ensuring the outflow of aqueous humor through the sclera by applying a series of laser applications around the perimeter at the site of each specific application, a closed a cavity, the pressure in which is less than atmospheric pressure, laser radiation is directed to the surface of the sclera inside the cavity, the intensity of the laser radiation reflected from the sclera is measured to determine its minimum and maximum values, when the ratio of these values takes on a value in the range 2.5- 3.0 laser radiation is stopped and the specified sequence of operations is repeated at an adjacent point of the perimeter of the ciliary body.

A device for the treatment of resistant open-angle glaucoma is known, containing an erbium laser with a wavelength of 1.56 μm in a quasi-continuous generation mode of 200/200 μs with a power of 0.75 W and an exposure of 4 s for each application (RU 2463029 "Method for the treatment of resistant forms of open-angle glaucoma" , IPC A61f 9/08, publ. 10.10.2011).

The disadvantage of the known device is the impossibility of controlling the time of laser irradiation of the sclera, depending on its hydropermeability. The exposure time is chosen by calculation based on averaged data, which reduces the effectiveness of treatment and can be dangerous for the patient.

The technical problem in creating a device for the treatment of various stages of open-angle glaucoma is to ensure the termination of laser radiation at the site of application when a predetermined IOP value is reached. In addition, two feedback loops are provided in the laser control system to ensure the efficiency and safety of the device. One is local (local), which controls the shutdown of the laser when a predetermined level of hydraulic permeability of the sclera is reached at the site of the laser application, and the second is general (global), which blocks the activation of the laser after the predetermined level of intraocular pressure is reached.

The technical result is to create a device that can automate the operation process, increase its efficiency and ensure the safety of the application of laser energy to the tissues of the eye.

The solution to the technical problem and the achievement of the technical result is ensured by the fact that in a device for the treatment of various stages of open-angle glaucoma, containing a laser with a working tool connected to it through an optical waveguide, the laser is connected through a controller via an electric line (circuit) to the electronic unit and one by one from two optical lines to the optoelectronic unit, and along the other optical line through the reverse coupler to the working tool connected through the return coupler to the optoelectronic unit, while the working tool is connected to the electronic unit by electric lines, and a switch is installed in the laser communication line with the controller. A dichroic mirror can be used as a reverse coupler.

The application of laser applications is carried out with an instrument connected by an optical waveguide with a laser. Such a tool is used in the implementation of the method according to patent RU 2463029. However, such a tool does not allow automatic shutdown of the laser when the normal IOP is reached at the site of application.

The technical problem is to overcome this drawback.

The technical result is to increase the effectiveness of treatment of various stages of open-angle glaucoma, to facilitate the work of an ophthalmologist.

The solution to the technical problem and the achievement of the technical result is ensured by the fact that a metal tube is placed inside the housing, inside of which an optical waveguide with a metallized inner layer passes. The end surface of this layer can be in contact with the eyeball, at the end of the tube there is an elastic hemispherical suction cup having a metallized surface on the inside, and the metallized surfaces of the waveguide and the suction cups are connected via electrical lines to the contact connectors intended for connection to the electronic unit of the device. In this case, the optical waveguide can be made in the form of a bundle of individual fibers, which are distributed inside the suction cup along the perimeter of the surface of the ciliary body at the points of laser applications.

The essence of the group of inventions is illustrated by diagrams in the figures.

FIG. 1 - Device diagram.

FIG. 2 - Diagram of a working tool.

FIG. 3 - Layout of the suction cup of the working tool suction cup on the eyeball.

Ftg. 4 - Scheme of the position of the sucker on the eyeball during the period of laser irradiation.

FIG. 5 - Scheme of the position of the sucker on the eyeball after the termination of laser irradiation.

FIG. 6 - Graph of changes in the intensity of forward and backward radiation during laser exposure to the sclera with constant average power.

FIG. 7 - Diagram of a tool suction cup with a waveguide in the form of a bundle of individual fibers

FIG. 8 - Section along a-A of Fig. 7.

FIG. 9 - Graph of pressure changes under the suction cup in the process of laser irradiation from the moment the laser is turned on and until it rebounds from the sclera and the laser is turned off.

The method is implemented using a device containing a laser 1, which is connected through an electric line through a switch 2 to a controller 3. The latter is connected to an electronic unit 5 through an electric circuit 4, used in the general feedback circuit, which blocks the laser from switching on after the moment of intraocular decrease. pressure to a given (normal) level. Through the optical signal circuit 6, the controller is connected to the opto-electronic unit 7 used in the local (local) optical feedback circuit. The light guide 8 is installed between the laser 3 and the optical coupler 9, which is connected via fiber optic lines with the working tool 10 and the optoelectronic unit 7. The working tool 10 has a housing 11 to which a suction cup 12 made of elastic material is attached. A seal 13 is placed between the housing 11 and the suction cup 12, which ensures the sealing of the cavity of the suction cup during operation of the device. On the surface of the housing 10 there are electrical contacts 14, 15 (Fig. 2) connected, respectively, to the metallized inner surface of the suction cup 12 and the metallized inner layer of the optical waveguide placed inside the tube 16 passing through the housing 10. Contacts 14. 15 along electric lines 17, 18 are connected to the electronic unit 5.

The proposed method for the treatment of various stages of open-angle glaucoma is implemented as follows. On the sclera of the eye in the place of the planned application, by pressing, a working tool 10 is installed using an elastic suction cup 12 (Fig. 3). When pressed, the air from the cavity of the suction cup is displaced, the radius of its curvature R increases to the value of R ₁ (Fig. 4). A vacuum with a reduced pressure P _ap arises inside the cavity. The pressure inside the cavity P _{ap is} significantly lower than the atmospheric P _a and below the intraocular pressure P. Thus, there is a differential hydraulic pressure on the scleral membrane ΔР. According to Darcy's law, there is a flow of moisture from the eye into the cavity proportional to the pressure drop and the hydropermeability K. Under normal conditions (without tissue irradiation), this flow is not large and does not cause an increase in pressure in the cavity. In this case, the metallized inner surface 19 of the suction cup 12 and the metallized end 20 (shown conditionally) of the light guide passing through the tube 16 come into contact with the sclera.

To carry out the application, the contacts of the switch 2 are closed and the voltage is supplied to the laser 1, which generates light radiation entering through the light guide 8 and the optical coupler 9 into the light guide located inside the working tool. To the point of application comes light from the laser 1 (shown in Fig. 1 by a solid line). At the same time, the electrical circuit of the device is closed. The current I ₀ (Fig. 4) passes through the circuit: controller 3, line 4, electronic unit 5, line 17, contact 14, metallized surface of the waveguide passing in the instrument, the surface of the sclera, contact 15, line 18. The signal obtained during the passage of current processed in the electronic unit 5.

When laser radiation enters the eye tissue, pores are formed, which leads to an increase in hydropermeability and a decrease in intraocular pressure. At the same time, an increase in the flow of liquid inside the cavity of the suction cup, which occurs during this, causes an increase in pressure in this cavity. As a result of increasing pressure in the said cavity, deformation of the elastic suction cup occurs. The radius of curvature of the inner surface of the suction cup varies from R ₁ to R (Fig. 5), and R> R ₁ . As a result of changing the radius of curvature, the contact between the metallized end face 20 of the light guide passing through the tube 16 and the surface of the eyeball is broken, and a gap h appears between them. The creation of a gap causes an open circuit in the above-named electrical circuit. The moment of disappearance of electrical contact with the sclera signals the completion of the process of increasing the hydropermeability to the value at which the vapor pressure under the suction cup is equal to VD. During irradiation, simultaneously with the formation of pores, the intensity of backscattered radiation entering the optical coupler 9 increases, which is a feedback signal for the operation of the optoelectronic unit 7 (Fig. 1). In the course of the experiments, a relationship was established between the intensity of direct radiation and backscattered radiation from the sclera (in Fig. 6 shown by a dotted line). It was found that in the range of the ratio of the ratio of the intensity of forward and backward radiation 2.5-3.0 (Fig. 6), VD decreases to a normal value. A break in the electrical contact means that it is necessary to stop the laser application. The signal about the termination of the electrical contact is sent to the electronic unit 5, from which this information is sent to the controller 5. When such information is received, the controller turns off the laser power and the application process ends.

It is obvious that one application may not be enough to reduce IOP. The permeability of the sclera in one place of application of the application can be achieved, and the IOP does not fall to the normal level. Therefore, the process of applying laser energy in one place is stopped and transferred to another point on the sclera. The working instrument is placed at a different point in the ciliary body and a new application process is started. And so they repeat, until the IOP drops to a normal level. In this case, the sucker “bounces”, the general feedback circuit is opened and the laser is blocked.

Thus, if the start of the application is started by the doctor by closing contact 2, then the termination of applications occurs automatically by blocking contact 2.

In order to ensure simultaneous application at several points of the ciliary body and, therefore, to shorten the operation time, the sucker is made to the size of the corresponding eyeball, and the part of the waveguide inside the sucker is made in the form of a bundle of separate waveguides. Each of these separate waveguides 21 of the bundle comes into contact with the surface of the ciliary body at a specific site of application (Figs. 7 and 8). The suction cup does not move over the surface of the eyeball, and the application is carried out simultaneously or sequentially by switching the supply of laser energy to different optical waveguides 21 of the bundle (Figs. 7 and 8).

With the help of the proposed device, experiments were carried out to irradiate the sclera of the isolated rabbit eye in one place in the projection of the ciliary body. Simultaneously with the irradiation, the pressure was monitored in the area of contact with the sclera, directly under the suction cup. With an increase in this pressure to a level at which the sucker bounced off, a decrease in IOP was achieved. FIG. 9 shows the dynamics of pressure under the suction cup in the process of laser irradiation from the moment the laser is turned on and until it bounces off the sclera and the laser is turned off.

The experiments carried out have shown the possibility of using the technical solutions of the present group of inventions for the treatment of the initial, advanced, advanced and resistant stages of open-angle glaucoma.

Claims (5)

1. A method of treating open-angle glaucoma by ensuring the outflow of aqueous humor through the sclera in the projection of the ciliary body by means of a series of laser applications along its perimeter, characterized in that at the site of each specific application using a working tool, a closed cavity is created, the pressure in which the pressure is less than the intraocular pressure located inside the cavity, laser radiation is directed, the intensity of the laser radiation reflected from the sclera is measured to determine its minimum and maximum values, when the ratio of these values takes a value in the range of 2.5-3.0 laser radiation is stopped and the specified sequence of operations is repeated in an adjacent point of the sclera along the perimeter of the ciliary body, and the working tool contains a housing, inside which a metal tube is placed, inside which an optical waveguide passes, which has a metallized inner layer, the end surface of which can be in contact be with the eyeball, an elastic hemispherical suction cup is placed at the end of the tube. 2. A device for the treatment of open-angle glaucoma, containing a laser with a working tool connected to it through an optical waveguide, characterized in that the laser is connected through a controller via an electric line to an electronic unit and along one of two optical lines to an optoelectronic unit, and via another optical lines through the reverse coupler to the working tool connected through the reverse coupler to the optoelectronic unit, while the working tool is connected to the electronic unit by electric lines, and a switch is installed in the communication line of the laser with the controller, and the working tool contains a body, inside which a metal tube is placed, inside through which an optical waveguide passes, which has a metallized inner layer, the end surface of which can contact the eyeball, an elastic hemispherical suction cup is placed at the end of the tube. 3. The device according to claim 2, characterized in that a dichroic mirror is used as a reverse coupler. 4. A working tool of a device for treating various stages of open-angle glaucoma, containing a housing, inside which an optical waveguide passes, characterized in that a metal tube is placed inside the housing, inside of which the specified optical waveguide passes, which has a metallized inner layer, the end surface of which can be in contact with with an eyeball, an elastic hemispherical suction cup is placed at the end of the tube, having a metallized surface on the inner side, and the metallized surfaces of the waveguide and the suction cups are connected via electric lines to contact connectors intended for connection to the electronic unit of the device. 5. The working tool according to claim 4, characterized in that the optical waveguide is made in the form of a bundle of individual fibers, which are distributed inside the suction cup over the scleral surface along the perimeter of the ciliary body at the points of laser applications.

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