SU1766404A1 - Method for correcting refraction anomaly - Google Patents

Abstract

The invention relates to medicine, namely to ophthalmosurgery and can be used to correct refractive errors (myopia of low, medium and high degree, astigmatism, etc.). The method of surgical correction of refractive errors is to apply non-perforating incisions to the cornea. The proposed method is characterized in that, in order to improve the safety and efficiency of the operation, micro-incisions are applied to the cornea and tunnels are made of them in the corneal stroma, the upper wall of which is dissected, and the lower wall of the tunnels is protected with guide protectors.

Description

The invention relates to medicine, namely to ophthalmosurgery, and can be used to correct refractive errors (myopia of weak, medium and high degree, astigmatism, etc.). The most common variant of the technique of anterior metered keratotomy (according to Fedorov) is to make radial or other in the direction of non-through cuts of the cornea from the side of its surface to the depth calculated by pachymetry. Under the conditions of a real-life clinic, even in the hands of experienced surgeons of microcetials of the descemetum, through cuts of its fabric with a small outflow of chamber moisture are not so rare (according to our data, on average 5-10 percent of operations). With more rapid knife handling, more extended perforations may be observed, which requires stitching and worsens the prognosis.

A known method for correcting myopia (ed. No. 940769, class A 61 F 9/00, 1978) by applying notches on the cornea from the border of the central optical zone to the limbus, the diameter of the central optical zone is preliminarily determined by the formula:

D -1.25 (1 + 6.5,

where D is the degree of reduction of corneal refraction;

d - diameter of the central optical zone.

This method does not exclude microprobes, which leads to subsequent complications.

A method of correcting myopia is also known (ed. No. 993936, class A 61 F 9/00, 1980), characterized in that, for 3-5 days after the incision of the cornea, the ocular block wears a non-correcting contact lens, which is removed after the time required to regenerate the cornea.

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This method also does not exclude microprobes and subsequent complications.

The prototype of the proposed invention is a method of surgical correction of myopia (ed. No. 1122315, class A 61 F 9/00, 1982, authors: S.N. Fedorov and others), which includes marking the central optical zone and applying to the cornea diminishing in depth from the periphery to the center of the non-perforated cuts, the depth of the cuts is changed stepwise, and the cuts are made from the periphery to the center.

The disadvantages of this technical solution include the complexity of the operation, since the depth of the incisions has to be varied in steps, the unevenness of scarring, as well as the increased trauma associated with the microseals.

The aim of the proposed solution is to increase the safety and efficiency of the operation.

This goal is achieved in that according to the method of surgical correction of refractive errors, which involve applying non-perforated cuts to the cornea, micro-incisions are applied to the cornea and tunnels are made from them in the corneal stroma .

Before the operation, patients are examined and, in addition to measuring the standard parameters of the eye, a pachymetric measurement of the cornea thickness at the limbus is performed in six meridians (in four direct and two oblique, in addition to measurements already taken at 4 and 7 j.

The following parameters are related to the measurement of standard eye parameters: cornea diameter in mm is determined using a special meter (vertical and horizontal diameters), cornea refraction in the center and peripheral zones (using an autokeratometer), rigidity of the cornea (using an Maklakov elastometer), the thickness of the cornea in the standard for keratotomy according to Fedorov points - in the lower nasal and lower temporal meridians from the center of the cornea to the periphery and, moreover, in the paralymbal zone on the main meridians 3, 6, 9 and 12 h (with using a keratopachometer). After that, clinical refraction is determined (on an autorefractometer), visual acuity is examined without correction and with correction, the patient's age is recorded.

The research results are entered into a computer and are processed according to a program developed by the head organization of the IRTC. Eye microsurgeons. Based on the results of the processed data, an individual variant of the subsequent operation of keratomy is calculated.

Immediately before the operation, the eyes are anesthetized with a 1% solution of dikain,

The patient is placed on the operating table under the operating microscope and the surgical field is treated. The eye slit expands with a dilator, after which the circle of the optical zone and the lines of future radial cuts of the cornea are applied to the cornea with the help of appropriate stamps. The eyeblock is fixed with double fork tweezers, the dosed diamond knife is exposed on

the depth of the incision, which is 10–15 microns, should be less than the thickness of the cornea at the limbus along each of the intended meridional incisions, subject to this condition the limbus along each of the intended

The meridians are performed in a notch with a length of 0.75-1.0 mm. Cuts are made directly from the limbus, if necessary, hemostasis is performed. Special trowel from the depth

each notch to the center of the cornea to the annular limiter of the optical zone, tunnels are made that are 20-50 microns from the Descemet's membrane (the layered nature of the corneal stroma allows this procedure to be performed without deviations from the intended plan and with a guarantee against random perforations of the Descemet membrane).

In each of the original cuts

after all the intended tunnels have been completed, the blade of a special diamond knife is inserted, which is pushed along the tunnel and cut a part of the corneal tissue located above the tunnel (i.e. between it and

cornea surface), while to prevent the cornea from cutting through, the tunnel bottom is protected with a special metal protector.

After that, using a cannula on

with a heated saline solution, the incisions are washed, the antiseptic drops are instilled, the expander is removed and a gauze bandage is applied.

PRI me R 1. Ill. F., 32 years. As a result of the examination, myopia of the moderate degree of the left eye was established. Visual acuity before surgery .050. with correction sf. -4,250, visual acuity 1.0.

Ophthalmometer: 44.37 - 96 °, 44.25 - 6 °. The cornea thickness at the center is 590 µm, at a distance of 3 mm from the center of 605 µm, at a distance of 7 mm from the center of 676 µm, at a distance of 11 mm from the center of 756 µm. The cornea diameter in the vertical meridian is 11.5 mm, in the horizontal meridian 11.5 mm.

Produced radial keratotomy by tunneling. Completed 10 radial notches, 02.20.90.

Ophthalmometer: 02.28.90 visual acuity 0.4, ref. + 4, OO cyl. -1, 90 ° 1; 03/02/90 visual acuity 0.5, sf. 1.50 cyl. -0.5, 03/05/90 visual acuity of 0.4, sf. + 1,, 0; 3/14/90 visual acuity 1.0.

Example 2. Patient G. 30 years. As a result of the examination, a high myopic degree of the right eye was established.

Ophthalmometer: Visual acuity 0.06, sf. -0 ,. -1.50, 0, 44.37073, 42.750163. The cornea thickness at the center is 512 µm, at a distance of 3 mm from the center of 535 µm, at a distance of 7 mm from the center of 623 µm, at a distance of 11 mm from the center of 681 µm.

Held tunnel keratotomi March 1, 1990. As a result of the operation: 02.03.90 visual acuity 0.3 sf. +4.00 - improvement; 03/05/90 visual acuity of 0.7 sf. + 1 ,. -1.50; , 03/15/90

- no worsening.

Example 3. Patient B., 36 years old. Diagnosis

- mixed astigmatism of direct type,

degree 6.00, visual acuity 0.08 sp. + 2.00 cyl.-4.00, 91 ° 0.7.

Ophthalmometer: 42.12 87 °

42.12 177 °

The cornea thickness at the center is 552 microns, at a distance of 3 mm from the center of 570 microns, at a distance of 7 mm from the center of 641 microns, at a distance of 11 mm from the center of 756 microns.

The tunnel keratotomy and longitudinal keratotomy 22.02.90 was produced. 6 cuts were made in the 91 ° meridian and no-cut btunnels in the perpendicular meridian. 02.22.90 visual acuity of 0.7 (uncorrective)

03/05/90 visual acuity of 0,6 st. + 1, .- 1,, 8

03/14/90 visual acuity 0.8-0.9 sp. + 0, .O, 75O,, 0

Claims (1)

Invention Formula A method for correcting refractive errors by making non-perforating incisions on the cornea, characterized in that, in order to increase the safety of the operation, micro-incisions are made in the cornea and tunnels are made of them in the cornea’s stroma, the upper wall of which is dissected, while the lower wall tunnel is protected by guiding protectors.