RU2010558C1 - Method and device for treating myopia and astigmatism - Google Patents

Abstract

FIELD: ophthalmology. SUBSTANCE: non-perforating measured sections are applied onto the cornea. Each section is made at first by pointed blade, then the blade with blunt edge is used to prolong the section; this blades has cutting side faces. Membrane is shifted simultaneously. Device for realization has casing, limiting rest, holder provided with blade and mechanism of measured longitudinal movement of the blade relatively the rest. The blade blunt-shaped edge and two cutting side edges disposed onto the opposite side faces. Length of any cutting edge corresponds to maximum thickness of the cornea. EFFECT: improved efficiency of treating. 2 cl, 6 dwg

Description

 The invention relates to medicine, namely to ophthalmology, and can be used for surgical correction of myopia of weak, moderate, high degree and astigmatism.

 There is a method of surgical correction of myopia and astigmatism, which includes marking, in addition to the central optical zone and lines of future cuts, one or more concentric to the center of the zones, respectively, which, when making cuts from the periphery to the center, the depth of corneal cutting is stepwise reduced, since the thickness of the cornea decreases from peripherals to the center.

The disadvantage of this method is:
high invasiveness of the operation and its long duration, due to multi-stage conducting of incisions, an increase in the number of marking elements, a forced increase in the number of incisions and their length, since the potential refractive effect of each incision is not fully used;
a high risk of such a complication as perforation of the cornea, due to the fact that the incision is made with a pointed blade along its entire length;
a large duration of preoperative examination, since numerous measurements of the thickness of the cornea and the calculation of the diameter of the zones of change in the depth of the incision are necessary;
the complexity of the operation for the surgeon, since accurate marking of areas for reducing the depth of the incision is necessary, otherwise the risk of complications increases significantly.

The technical result obtained by the implementation of the proposed method is:
less invasiveness of the operation and shorter lead time due to: reducing the risk of perforation of the cornea, since a blade with a blunt ending is used, reducing the number of corneal cuts or reducing their length, as all the potential refractive effect from each section is realized, reduction of marking elements due to the lack of step section, the absence of the need for multiple changes in the length of the exit blade;
shorter examination time for the patient, since the number of measurements of the thickness of the cornea is not more than two, there is also no need to calculate areas for reducing the depth of cut;
less possibility of reducing the refractive effect of the operation in the postoperative period, since all layers of the cornea above the descemet membrane are cut;
great simplicity of the technique, which does not require highly qualified surgeon;
the possibility of incisions both from the periphery of the cornea to the center, and from the center of the cornea to its periphery;
the ability to perform an operation without measuring the thickness of the cornea, using the average value of the thickness of the cornea at the periphery.

 The essence of the method lies in the fact that in the method of surgical correction of myopia and astigmatism by applying non-perforating cuts to the cornea, the latter, up to the depth of the descemetic membrane, begin with an injection of a pointed blade, and continue with a blunt end blade and cutting lateral faces, while at the same time pushing the Descemetov membrane, thereby avoiding its perforation.

 A number of devices are known for applying non-perforating cuts to the cornea of the eye, consisting of a body, a stop, a holder with a blade and a dosed longitudinal movement of the blade relative to the stop. However, these devices, having differences in the mechanism of adjusting the exit of the blade and appearance, all have a pointed blade, which sharply enters the tissue of the cornea of the eye, but with a further section, it is also easy to perforate the Descemet membrane, so the surgeon is forced to avoid contact of the blade with the Descemet membrane. This means that when performing an incision with these devices, a layer of corneal tissue above the descemet membrane always remains undissected, which reduces the potential result of the operation. Otherwise, if the surgeon wants to strengthen the effect of the incision, complication easily arises.

The technical result obtained by the implementation of the proposed device is:
a significant reduction in complications such as perforation of the cornea, since when carrying out the incision with the proposed device, the blunt end of the blade pushes the Descemet membrane away without perforating it;
increasing the efficiency of the operation, since cutting the lateral edges of the blade, which extends beyond the restrictive emphasis by a length close to the maximum thickness of the cornea, is almost completely dissected throughout the incision in the tissue over the descemet membrane;
the universality of the use of the device both when making cuts from the center and from the periphery of the cornea, as well as when making a cut, first in one direction, and then in the other without removing the blade from the cut.

 This is achieved by the fact that in the device for conducting ophthalmological operations, comprising: a body, a limit stop, a holder with a blade and a dosed longitudinal movement of the blade relative to the stop - the blade has a blunt end and a cutting side face.

 In FIG. 1 shows the proposed device for applying to the cornea non-perforating dosed sections, where there are: a body 4, a blade holder 3, a stop 2, a blade 1, a dosed longitudinal movement of the blade 5.

 In FIG. 2 shows a close-up of the end part of the blade holder 3 and the blade 1 with a blunt end and two cutting side edges 2. In FIG. 3 shows, as an option, a blade with one cutting side edge 2 and a blunt end, the second face does not have a cutting edge.

 In FIG. 4 shows a cornea 6 with a section profile (shown by hatching), where the dotted line indicates the part of the section made by a pointed blade (the smaller part) and the part of the section made by a blunt-ended blade, descemet membrane 7. In FIG. 5, for example, a section profile is shown with a stepwise method of conducting an operation with a pointed knife, where the first notch level is delimited from the second dotted line. In FIG. 6 shows the moment of the cut by the proposed device, where the blade with a blunt end and a cutting side face 1, having an exit beyond the limit stop 2, greater than the thickness of the cornea at this point, pushes the Descemet membrane 7 and dissects the tissue of the cornea 6.

 The proposed method is as follows. Before the operation, all the necessary examinations are carried out, including measuring the thickness of the cornea in the center and on the periphery. A few minutes before the operation, superficial anesthesia of the eye is performed with dikain - 1%. Next, markers mark the central optical zone and the lines of future sections. The eye is fixed with tweezers at the limb. An incision is made with a microsurgical knife with a pointed blade, and the blade exit should not exceed the thickness of the cornea at the injection site. The length of this section of the incision is sufficient up to 1.5 mm, in practice it can simply be injected into the cornea. After that, the proposed device with the exit of the blade slightly smaller than the maximum thickness of the cornea continues the incision to the intended length, dissecting the corneal tissue above the descemet membrane, pushing the latter with the blunt end of the blade. If necessary, if the device has a blade with two cutting lateral edges, the cut can be extended in the opposite direction, without removing the device from the cut. The operation is completed by washing the incisions and injecting an antibiotic under the conjunctiva.

 The method is illustrated by examples.

PRI me R 1. Patient K., 23 years. Diagnosis: right eye myopia 7.5 D, left eye myopia - 8.25 D. Ophthalmometry: right eye - 43.2 D - 94,
- 42.6 D - 3. left eye - 43.4 D - 86,
- 42.9 D - 176.

 The thickness of the cornea of both eyes in the center is 530 μm, on the periphery of the limb - 720 μm.

 An operation was performed - anterior radial keratotomy of the left eye. Under local anesthesia with 1% dicaine solution, 12 radial incisions were made epibulbarly with a diameter of the central optical zone of 3.2 mm. The depth of the incision made by a pointed blade, 700 μm, length 1.5 mm. The blade of the microsurgical knife with a blunt ending had a yield of 680 microns. With this exit of the blade, the cuts are brought to the edge of the optical zone. The duration of the operation is 7 minutes

When viewed on the first day: a small mixed injection of the conjunctiva of the left eye, the incisions are clean. Distant vision improved dramatically, but somewhat difficult near. On the 5th day, the visual acuity of the left eye with + 0.75 D - 1.0. Ophthalmometry: 34.6 D - 92,
34.1 D - 1.

On the 6th day, the operation of the right eye was performed according to the same technique, the postoperative period without complications. On the 12th day after the 1st operation, the vision of the left eye is 1.0 n / a, ophthalmometry: 35.4 D - 93,
35.3 D - 2.

Vision of the right eye - 0.8 s + 0.75 D - 1.0, ophthalmometry: 34.2 D - 87,
34.0 D - 176.

 After 1 month from the day of the first operation, the visual acuity of the right eye is 1.0, the visual acuity of the left eye is 0.9 s - 0.25 D - 1.0. The patient does not complain of vision.

PRI me R 2. Patient S., 34 years. Diagnosis: right eye myopia 9.0 D, left eye myopia - 5.25 D. Ophthalmometry:
right eye - 44.1 D - 112,
43.2 D - 21;
left eye - 43.4 D - 81,
42.7 D - 172.

 The thickness of the cornea of both eyes is 530 microns in the center, 720 microns - on the periphery of the limb. Under local anesthesia with a 1% solution of dicain, an operation was performed - anterior radial keratomy of the right eye. 12 corneal incisions were made with preservation of the optical zone with a diameter of 3.2 mm. A pointed surgical knife held the initial section of the incisions 1.5 mm long, 700 μm deep. Next, a microsurgical knife with a blunt-pointed blade, and its output at 690 μm, the sections were brought to the optical zone.

On the 1st day, conjunctival injection is moderate, the incisions are clean, the patient notes a sharp improvement in vision, moderate lacrimation. On the 5th day, the visual acuity of the right eye was 0.8 n / a, ophthalmometry: 34.8 D - 101, 35.0 D - 10. On the 6th day, an operation on the left eye was performed using the same technique. 6 sections of the cornea were performed, the optical zone was 3.2 mm. The depth of the initial part of the cuts is 700 μm, the length of the exit of the blade with a blunt end during the rest of the cuts is 680 μm. On the first day, conjunctival injection is moderate, the incisions are clean. After 1 month, the visual acuity of the right eye is 0.8 n / a, the left eye is 0.8 s -0.75 D is 1.0. Ophthalmometry:
right eye - 35.3 D - 100,
35.1 D - 9,
left eye - 37.8 D - 80,
37.2 D - 169.

 The patient does not complain of vision.

 The proposed method performed 32 operations in the eyes of 16 patients. During the operation and in the postoperative period, complications were not identified. Contraindications to the method are degenerative and traumatic changes in the cornea of the eye, high degree of amblyopia.

Claims (3)

 1. A method of treating myopia and astigmatism, including applying non-perforating metered incisions to the cornea, characterized in that the incision is started with an pointed pointed blade and continued with a blunt end and cutting side faces, while at the same time the Descemet membrane is pushed back.  2. A device for conducting ophthalmological operations, comprising a housing, a limit stop, a holder with a blade and a dosed longitudinal movement of the blade relative to the stop, characterized in that the blade is made with a blunt end and two cutting side edges located on opposite side faces, the length each cutting edge is made corresponding to the maximum thickness of the cornea.  3. The device according to p. 2, characterized in that the blade is made with one cutting side edge.

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