SU1637797A1 - Device for surgical treatment of myopic astigmatism - Google Patents

Abstract

The invention relates to medical technology, in particular to ophthalmic devices for the surgical treatment of the eye in myopic astigmatism by laser irradiation of its cornea. The goal is to improve the accuracy of obtaining a given shape of the corneal surface while simultaneously forming the entire radiation flux and reducing the time of treatment. The device contains a pulsed laser 1, a housing 2, a laser radiation conversion element enclosed in it in the form

Description

about her

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two cylindrical telescopic lenses 3 and 4 in the frames 5 and 6, which can rotate relative to each other, absorbing medium 7 and channels 8 for circulating this medium. The inner surfaces of the lenses 3 and 4 are convex cylindrical surfaces.

1637797

t of rotation of the 2nd order. The impact of the radiation beam 11 on the cornea 12 of the eye 13 leads to photo-evaporation of such a layer of the cornea, the removal of which is necessary for the correction of vision in the case of myopic astigmatism. 1 il.

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The invention relates to a medical technique, in particular, to ophthalmic devices for surgical treatment of the eye during myopic astigmatism by exposing the cornea to laser radiation.

The purpose of the invention is to improve the accuracy of obtaining a given shape of the surface of the cornea while at the same time forming the entire radiation flux and reducing the treatment time.

The drawing shows a diagram of the proposed device.

The device contains an ultraviolet pulsed laser 1, a housing 2. a unit for converting laser radiation into it in the form of two; cylindrical telescopic lenses 3 and 4 into the frame 5 n 6, which can rotate relative to each other around the axis of the laser beam, absorbing medium 7 (gas or liquid) and channels .8 for circulating the absorbing medium. The inner surfaces of the lenses 3. and 4 are convex cylindrical surfaces of rotation of a second to a row.

The device works as follows.

A parallel beam of radiation emerging from the laser 1 with a uniform distribution of the energy density over the beam cross section passes through the lens 3 and the parallel beam 10 passes through space. between lenses 3 and 4. Due to the fact that the thickness of the medium layer 7 is not constant, the radiation absorption in the medium 7 leads to an uneven (cross section) weakening of the radiation effect, so that the parallel radiation beam 11 transmitted through the lens 4 has an uneven density distribution45

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These energies have two symmetry planes, the shape and parameters of which are determined by the shape of the inner surfaces of the lenses 3 and 4, the absorption coefficient of the medium 7, depending on the pressure of the absorbing gas or on the concentration of the solution in the case of using a liquid medium, as well as on the angle between the main lens planes, which may vary from zero to. The impact of the radiation beam 11 on the cornea 12 of the eye 13 leads to photo-evaporation of such a layer of the cornea, the removal of which is required for vision correction during hypermetropic astigmatism of the eye.

Claims (1)

Invention Formula A device for the surgical treatment of myopic astigmatism, comprising a UV pulsed laser and a laser radiation conversion element enclosed in a housing, characterized in that, in order to increase the accuracy of obtaining a given corneal surface shape while simultaneously forming the entire radiation flux and reducing the treatment time two cylindrical telescopic lenses, the inner surfaces of which are convex cylindrical surfaces of the second order, and the lenses They are enclosed in frames with the possibility of their rotation relative to each other around the axis of the laser beam and the change in the angle between the main planes of the lenses in the inter-. between zero and / 2, while the space between the lenses is filled with the medium absorbed by the laser radiation, connected by channels for its circulation made in the housing.