RU2122390C1 - Device for through keratoplasty - Google Patents

Abstract

FIELD: medicine; ophthalmosurgery. SUBSTANCE: device is made in the form of diamond microknife. It contains concave-convex transparent lens. Lens curvature radius corresponds to average curvature radius of man's cornea, and its diameter is 2-3 mm larger than average diameter of cornea. Through hole in the form of extended oval is made in lens to receive microknife blade. Form and dimensions of through hole correspond to those of noncutting part of diamond microknife. Lens is superimposed on cornea surface so that hole for arrangement of diamond microknife blade is aligned with trepanation incision, and lens is positioned concentrically with corneoscleral limbus. Then cutting out of cornea through disc is completed by moving the microknife exactly along incision made by trepan. EFFECT: additional cutting of cornea tissues after trepanation with minimum traumatizing of incision edges and obtaining of correct form of cut-out disc. 4 dwg, 1 expi

Description

 The invention relates to medicine, namely to ophthalmology, and can be used for surgery through keratoplasty, in particular for the final cutting of corneal tissue after trepation.

It is known to use microscissors for cutting corneal tissue after trepanation using curved microscissors (A. Callahan. Surgery of eye diseases. - Medgiz: 1963, p. 170). The disadvantages of the known microscissors are:
- trauma to the edges of the incision, since cutting tissue with scissors is associated with squeezing;
- the difficulty of obtaining steep edges of the section;
- the irregular shape of the resulting cut due to mismatch of the radius of curvature of the branch of the scissors and the trepanation hole.

 It is known to use viscoelastic materials (hyalon, vizitin) to maintain the depth of the anterior chamber of the eye when opening it. However, this is possible with relatively short corneal incisions. Often with through keratoplasty, the total length of the incision is such that the hyalon in the anterior chamber is not held.

 A device for end-to-end keratoplasty, made in the form of a diamond micro-knife (Abstracts of the International Conference on Keratoplasty and Keratoprosthetics, Odessa, September 27-29, 1978, pp. 37-38).

 The specified device is an object of the same technical purpose and is taken as a prototype. It is a diamond coronal section and use it to remove deep muddy layers of the cornea, as well as reduce unevenness of the bed. For cutting corneal tissue after trepanation, it is not applicable.

 We set the task of developing a device that allows the cornea to be cut after trepanation with minimal injury to the edges of the incision, to obtain the correct shape of the cutting disc, to maintain the depth of the anterior chamber of the eye by preventing leakage of viscoelastic material from the anterior chamber.

 The problem is solved by using the proposed device, made in the form of a diamond micro-knife, containing a rigid concave-convex transparent lens located concentrically to the corneoscleral limb, the radius of curvature of which corresponds to the average radius of curvature of the human cornea, and the diameter is 2 ... 3 mm larger than the average diameter of the human cornea in which a through hole is made in the form of an elongated oval to accommodate a diamond micro-knife blade, followed by advancement along the trepanation notch, shape and size of the through-hole corresponding to the shape and size of the non-cutting diamond microblade.

 In FIG. 1 schematically shows the anterior section of the eyeball after trepanation; figure 2 - the position of the lens applied to the cornea after trepanation, viscoelastic is introduced into the anterior chamber; figure 3 - the position of the diamond micro knife when cutting corneal tissue; figure 4 is a top view.

 The device for penetrating keratoplasty is made in the form of a diamond micro-knife, contains a convex-concave lens 1 of a transparent rigid material, has a through hole, which is located so that when concentrating the lens on the cornea, it coincides with the edge of the trepan disk. The dimensions and shape of the hole correspond to the size and shape of the non-cutting part of the diamond micro-knife.

 The device is used as follows. Corneal trepanation 2 is performed before opening the anterior chamber. Through the resulting through incision 3, viscoelastic substance 4 (hyolone, vizitin) is introduced into the anterior chamber in an amount sufficient to restore the normal depth of the anterior chamber. After that, a concave-convex lens 1 is applied to the surface of the cornea so that the hole 5 of the lens 1 coincides with a trepanation incision, and the lens is concentric with the corneoscleral limb. Then, by advancing the micro-knife 6 precisely on the notch made by a trepan, the cutting of the through corneal disc is completed. In the process of cutting, the lens holds the domed shape of the cornea, prevents the flow of viscoelastic from the corneal incision, and maintains a constant depth of the anterior chamber. After the corneal disk is cut, the device and the disk are removed, while the viscoelastic material extends beyond the front chamber. Residues are removed by washing. After that, the operation is continued according to the generally accepted technique.

 Using the proposed device can significantly reduce the risk of injury to the iris and lens during cutting of the corneal disc after trepanation. Due to the fact that the lens of the device prevents the outflow of viscoelastic material and thereby maintains a constant depth of the anterior chamber.

 Example: Patient K., 12 years old, was admitted with a diagnosis of OD - a consequence of a penetrating wound of the cornea, corneal scar. Visual acuity: 0.1 does not correct. The operation was performed using the proposed device.

 A trephine with a diameter of 7 mm produced an incision of the cornea before opening the anterior chamber. Through a through incision of the cornea, viscoelastic is introduced into the anterior chamber. After restoration of the normal depth of the anterior chamber, a lens is applied to the cornea, and a diamond micro-knife blade is inserted through an opening in it into the trepanation incision. Then, with the movement of the diamond micro-knife along the trepanation incision, the corneal disk was cut. A transplant of a donor cornea is placed on a bed prepared in this way, which is fixed with 16 interrupted sutures 10-0. No complications during surgery, such as damage to the iris or lens, were observed. Sufficient depth of the anterior chamber remained during the entire time the corneal disc was cut. Received a hole of regular round shape with sheer edges. The clinical observation allows us to conclude: the proposed device for end-to-end keratoplasty allows to achieve the goal, namely, to ensure the possibility of cutting corneal tissues after trepanation with minimal injury to the edges of the incision, obtaining the correct shape of the disc being cut out and maintaining the depth of the anterior chamber of the eye by preventing leakage of viscoelastic material from anterior chamber of the eye, and thereby provide a higher functional result of the operation.

Claims (1)

 A device for end-to-end keratoplasty, made in the form of a diamond micro-knife, characterized in that it contains a rigid concave-convex transparent lens located concentrically to the corneoscleral limb, the radius of curvature of which corresponds to the average radius of curvature of the human cornea, and the diameter is 2-3 mm larger than the average diameter of the cornea eyes, in which a through hole is made in the form of an elongated oval to accommodate a diamond micro-knife blade, followed by advancement along a trepanation notch, with the shape and size s of the through hole correspond to the shape and size of non-cutting portion of the diamond microblade.

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