SU1192818A1 - Method of removing intraocular metal foreign bodies - Google Patents

Description

The invention relates to medicine and can be used in ophthalmosurgery to remove metallic intraocular foreign bodies.

The aim of the invention is to reduce trauma to the tissues of the eye and increase the reliability of fixation of a foreign body.

The method is as follows.

Through the incision of the eye shells, the tip of the probe with electrodes is introduced into the eye cavity and is brought to the foreign body. When both electrodes touch a foreign body, placing the electrodes around the foreign body, the circuit is closed and the foreign body is welded to the electrodes. The tip of the device along with the foreign body is removed from the eye. The voltage on the electrodes is 15–40 V, the current is 0.01–0.6 A.

The drawing shows a diagram of the device that implements the method.

The device contains two electrodes 1, separated by an insulating material, mounted in the body-holder (probe)

2, matching circuit 3, waiting for a multivibrator 4, gang forming unit 5 of a constant constant current, a dial current indicator 6, a light signaling unit 7, an audible alarm multivibrator 8, a power supply unit 9, the electrodes 1 being connected to the matching circuit 3 input, the output of which is connected with the input of the standby multivibrator 4 and the multivibrator 8 audible alarm, the output of the standby multivibrator is connected to the matching circuit 3 and to the input of the block 5 of the formation of a gated constant stabilized current, the output of which is connected to the dial current indicator 6 and the light signaling unit 7, as well as through the matching circuit 3 is connected to the electrodes 1, the output of the power supply unit 9, which forms a constant stabilized voltage of 5V, is connected to the matching circuit 3, the waiting multivibrator 4 and the multivibrator 8 sound signaling, and the output with voltage ZOV — to block 5 of the formation of a gated constant stabilized current.

The device works as follows.

The device connects to AC power. The power supply unit 9 provides a stabilized DC voltage of 5V to the matching circuit 3, the waiting multivibrator 4 and the multivibrator 8 beep alarm, and the voltage COV to the block 5 of the formation of the gated constant stabilized current. When electrodes 1 of probe 2 are touched to a metallic foreign body, a short circuit signal is supplied to the matching circuit 3, which contains the operating control control body, a decoupling circuit on a diode array, and an electronic switch that converts the short circuit signal to a logical “0” signal. A logical multivibrator 4 is triggered by a logical “0” signal, which generates a negative U-shaped pulse to start the gated source 5 of a stabilized current, has a control “Setting the pulse duration” and “Monitoring the current setting” using the dial indicator 6. Gated source 5 of the stabilized current when a trigger pulse arrives, it opens and produces a positive U-shaped current pulse, which has a duration corresponding to the trigger pulse duration and Whose value is preset at the current dial gauge 6 governing body "Replacing current value" strbirovannom available in the constant current source 5. The current pulse when the voltage on the electrodes 1 15-40 V and a current of 0.01-0.6 And goes through a decoupling circuit of the circuit 3 of the agreement and the electrodes 1 to a metal foreign body, flowing through which causes the effect of contact welding of a foreign body to the electrodes 1 probe 2. The moment of welding of a foreign body to the electrodes 1 and the presence of a closed circuit between the electrodes 1 is fixed using the matching circuit 3 and the waiting multivibrator 4, which in this case generates a logical signal "3" and through the junction circuit 3 ivibrator 8 audible alarm. The device provides a range of choice of pulses from 0 to 60 V and a current from 0 to 1 A, which makes it possible to select the optimal welding modes depending on the parameters of an intraocular metal body over a wide range.

Example 1. The proposed method of removing metallic foreign bodies and the device for its implementation tested on 15 experimental rabbits. The model of intraocular foreign body in animals was obtained as follows.

After the pupil was diluted three times by instillation of 1 ° / atropine into the eye and intramuscular injection of sodium thiopental at the rate of 1 ml per 1 kg of rabbit weight, it was tied to a special machine with head fixation. Eyelids were smeared with alcohol and covered with a sterile eyecup. After epibulbar anesthesia with a threefold instillation of a 0.25% solution of dikain and a retrobulbar injection of 2 ml of a 2 ° / novocaine solution, the third eyelid was taken with surgical forceps and cut with scissors. Eyeball sprained

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glass rod and fixed in this position with sterile gauze flagellum.

In the upper outer quadrant of the eyeball, in the flat part of the ciliary body, all the membranes of the eyeball were punctured with a cutting knife. A needle was introduced into the cavity of the eyeball, from which a mandrin was used to push a piece of steel wire with a diameter of 0.5 mm and a length of 1.5-2 mm, which, by virtue of its gravity, fell onto the fundus of the eye. In 5 rabbits when pushing mandrin from a needle. a piece of wire its distal end partially embedded in the retina. Then the needle was removed. In the eye slit were buried ZO ° / o-ny solution of albutside. The rabbit was placed in a cage. After 3 days, the operated eyes were calm. All 15 rabbits in the fundus of the eye was determined by a foreign body. In 5 animals it was partially impacted into the retina, there were small foci of hemorrhages around the foreign body. In the remaining 10 rabbits, the foreign body in the fundus of the fundus was fixed to the inner membranes by fibrin and did not move when turning the head of the animal. 2 weeks after the introduction of a foreign body into the cavity of the eye, an operation was performed to extract it by the proposed method and device.

The method of extracting a metallic foreign body from the eye was carried out as follows.

After maximum expansion of the pupil by instillation into the eye slit of a 1% solution of atropine and the introduction of intramuscular thiopental at the rate of 1 ml per 1 kg of rabbit weight, they were tied to a special machine with head fixation. The operative field was treated with alcohol and covered with a sterile eyecup. After epibulbar anesthesia with a threefold instillation into the eye slit of a 0.25% dikain solution and a retrobulbar injection of 2 ml of a 2% novocaine solution, the eyeball was dislocated with a glass rod and fixed in this position with a sterile flagellum. In the upper-outer quadrant of the eyeball, in the region of the flat part of the ciliary body (in the same place)

I made an incision in the membranes of the eyeball with a cutting knife. Through the formed incision in the membranes of the eye, the tip of the device included in the electrical network was inserted into the vitreous body, and under the control of the ophthalmoscope, the tip was brought to the foreign body on the fundus. At the moment of contact of the electrodes of the probe with a metallic foreign body, a sound alarm appeared in the device that the foreign body was fixed. The tip along with the foreign body was removed. On the edges of the wound, due to the small size

(2 mm), the seam is not imposed. As a result of the experiment, the limits of the thresholds of the optimal modes of welding to the probe of intraocular metallic foreign bodies were established. In terms of the level of pulses on the electrodes, they corresponded to values of 15–40 V with a current strength of 0.01–0.6 A.

At pulse levels below 15V, welding of the foreign body to the probe electrodes was not strong enough; above 40 V, significant vitreous coagulations occurred. The optimal mode in each specific case was determined by a gradual increase in the level of pulses on the electrodes in the range from 15–40 V and current strength from 0.01–0.6 A to the implementation of durable welding of a metallic foreign body to the probe.

Example 2. Patient D. is 24 years old on the 3rd day after injury with a diagnosis of penetrating wound of the cornea, intraocular foreign body, included in the sheath of the posterior pole of the right eye. On the cornea there is a paracentral corneal wound with adapted edges. Front camera of normal depth. The lens is transparent. In the vitreous body slight turbidity. In the fundus below the optic nerve head, a metallic foreign body impacted in the eye membrane is covered with fibrin. Visual acuity 1.0. Peripheral boundaries of the visual field and intraocular pressure within normal limits. On the Comberg-Baltin radiograph in the right eye, there is a shadow of a metallic foreign body 1x0.5 mm in size along the Zch 50 meridian, at a distance of 8 mm from the anatomical axis and 22 mm from the plane of the limbus. In the study of the magnetometer magnetic properties are not detected. Ophthalmic magnetic test is negative.

The operation was performed - removal of a copper intraocular foreign body impacted into the shells of the posterior pole of the eye. After epibulbar anesthesia with a 1/4% solution of dikain, 0.2 ml of a 0.1% solution of adrenaline was injected under the conjunctiva of the eyeball to maximize pupil expansion. A speculum was inserted into the eye slit. For fixing the eyeball, a bridle suture was applied to the upper rectus muscle. On the meridian of 10 h ’and 2 h in 4 mm from the limbus and parallel to it, a 5 mm long conjunctiva was incised. In the same places, the punctures of the eye membranes were made with a scissors knife. A soft fundus lens was placed on the cornea, through which a foreign body was found on the eyeball under a microscope. Through punctures in the sclera, a micro spatula and a probe for electric welding were introduced into the eye cavity. The voltage on the probe electrodes was 25 V. At the moment of contact of both electrodes of the probe with the foreign electrode

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the electrical value of the internal body occurred, resulting in a sound signal in the device, indicating the fixation of a foreign body to the tip of the probe. After releasing the foreign body from the membranes and fibrin using a micro spatula, the foreign body, fixed to the tip of the probe, is removed from the eye. On the edges of the scleral wounds, silk silk was applied one at a time, and knotted silk sutures on the edges of the conjunctival wounds. Under the conjunctiva introduced 100 thousand units. streptomycin. Applied a binocular bandage. Bed rest for three days. Disinfectant drops and streptomycin once daily for a period of three days. Starting on the 4th day, the decadence is narabulbarno but 0.5 ml every other day.

On the 12th day after the operation, the patient was discharged with a calm eye, a delicate corneal scar, a chorioretinal focus at the site of the removed foreign body. The lens and vitreous body are transparent. Acuity of maturity 1.0. Peripheral boundaries of zero vision and intraocular pressure within normal limits.

In the long-term follow-up (5.5 months), the eye is calm. Chorioretinal scar is not visible. Eyeball without visible pathological changes. Visual acuity - 1.0. Visual field and intraocular pressure within normal limits.

The proposed method using the device for its implementation operated on 7 patients aged 16 to 52 years with metal, non-magnetic foreign bodies, localized in the back of his eye section. As a result of the operation, in all 7 patients, metal foreign bodies were removed without complications. Any changes associated with electric welding in the vitreous body, the inner membranes and the anterior part of the eye according to biomicroscopy and ophthalmoscopy were not found. Visual acuity in all patients remained from 0.6 to 1.0. The chorioretinal focus remained in place of the foreign body impacted into the eye shell. Terms of remote observations more than 5 and 1-3 months.

Claims (2)

METHOD FOR REMOVAL OF INTRA-GLAZE METAL FOREIGN BODIES by attaching a foreign body to the probe, characterized in that, in order to reduce trauma to the eye tissues and improve the reliability of fixation of the foreign body, the probe is two parallel electrodes, while the latter are located on both sides of the foreign body, and its attachment to the probe is carried out by spot welding at a voltage on the electrodes of 15–40 V and a current of 0.01–0.6 A. 1192818 2 one