RU2614102C2 - Drainage for intraocular fluid outflow - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention refers to medicine and aims at surgical treatment of various types of glaucoma. The proposed drainage has an oval form, maid as a collapsible corrugated structure with a possibility of folding. Drainage is thickened in the central part and has a claw-like elements at the edges.

EFFECT: invention provides not only the effect of intraocular pressure normalisation, but also the prolonged therapeutic effect on eye tissues.

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Description

FIELD OF TECHNOLOGY

The invention relates to medicine and is intended for the surgical treatment of various types of glaucoma.

Glaucoma is a disease that causes damage to the optic nerve as a result of increased intraocular pressure. One of the main methods for reducing excessive pressure is surgical, which consists in creating additional ways for the outflow of intraocular fluid. Drainage implantation is one of the stages of the operation, provides compensation for intraocular pressure and prevents the formation of intrascleral adhesions.

BACKGROUND

A known model of drainage for anti-glaucoma operations, made in the form of a tube of cylindrical shape with porous walls (US patent No. 5968058), used in secondary glaucoma and implanted at one end into the anterior chamber of the eye, and the other, the outer end, under the conjunctiva. The proposed drainage design does not exclude its dislocation into the anterior chamber of the eye at different times after implantation, which can lead to trauma to the iris or endothelium of the cornea and cause recurrent hyphema, iridocyclitis, and epithelial-endothelial dystrophy of the cornea. The stiffness of the cylindrical drainage can lead to excessive expansion of the puncture of the sclerotic corneal tissue at the injection site into the anterior chamber during eyeball movements and, in turn, lead to the development of the small anterior chamber syndrome and then to its complete emptying, which is fraught with detachment of the choroid, prolonged hypotension and macular edema. Drainage of the proposed form and with the proposed method of fixation can also shift under the conjunctiva, which leads to the loss of its drainage role. In addition, the drainage lumen can become clogged with blood or hemose fibrin, which prevents the drainage from performing its function and reduces the hypotensive effect of antiglaucoma surgery. Also, the implantation of a cylindrical drainage requires additional suture fixation, which requires additional time and a certain qualification of the surgeon. In addition, the material from which this model is made does not prevent the formation of a connective tissue capsule around, and, thus, a rapid obliteration of the formed drainage paths occurs and the drainage loses its functions.

Also known patent "Drainage for anti-glaucoma operations" of the Russian Federation No. 2309781, authors Pashtaev Nikolay Petrovich (RU), Gorbunova Nadezhda Yuryevna (RU), Treushnikov Valery Mikhailovich (RU), Viktorova Elena Aleksandrovna (RU), Starostina Olga Valeryevna (RU). For the manufacture of drainage, a new polymer material, Digel, is synthesized, which is a transparent polymer obtained by photopolymerization of a mixture of monomers and oligomers. The perforated drainage structure allows incoming HPW to circulate in all directions and stimulates all possible routes of intraocular fluid outflow in patients with refractory glaucoma. Designed for the surgical treatment of refractory glaucoma.

A method for the treatment of refractory glaucoma (RF №2313314) Pashtaev Nikolay Petrovich (RU), Gorbunova Nadezhda Yuryevna (RU) is considered by us as a prototype. The invention is intended for the surgical treatment of refractory glaucoma. Separate the superficial scleral flap with the base to the limb and exfoliate the sclera beyond the scleral bed with the formation of an extensive intrascleral pocket. A deep scleral flap is removed and a rectangular perforated drainage of polymer material is implanted. The drainage is made in the form of a rectangular plate 100-200 microns thick with through holes.

However, implantation of this drainage does not exclude fouling with its connective tissue capsule, which leads to the formation of sclero-scleral adhesions. The dimensions of the openings in the mesh drainage are insufficient for the free circulation of intraocular fluid, which leads to the subsidence of blood elements or hemose fibrin on the surface of the drainage, which, in turn, prevents the drainage from performing its function and reduces the hypotensive effect of antiglaucoma surgery, especially in the long term.

SUMMARY OF THE INVENTION

The aim of the invention is the creation of a new type of drainage from chitosan for the outflow of intraocular fluid used in surgical operations for the treatment of various types of glaucoma, which has significant advantages over prototypes, biocompatibility, the creation of a stable hypotensive effect due to the formation of the intrascleral outflow pathway and prolonged therapeutic effect due to the biodestructive properties of chitosan.

Justification of the choice of material and the resulting technical result. Chitosan is a derivative of the crustacean chitin biopolymer. Chitosan is destroyed in humans and animals to ordinary substances, N-acetylglucosamine or glucosamine. Chitosan has immunomodulatory, antimicrobial, fungistatic, anti-inflammatory, hemostatic effects. This biopolymer activates neutrophilic leukocytes and macrophages, while enhancing their functional activity (synthesis of cytokines and superoxide production), is a biostimulator. Chitosan has all the indicators necessary for drainage, namely high biocompatibility, the complete absence of allergic and inflammatory reactions, elasticity, the ability to create the necessary shape and size, and the possibility of biodegradation.

The technical result is a stable normalization of intraocular pressure in patients with various types of glaucoma due to implantation of drainage from chitosan during antiglaucomatous operations.

The technical result is achieved by the fact that drainage from chitosan is implanted in the intrascleral space. The formation of an intrascleral space is one of the main elements of antiglaucomatous operations and is used both for perforating (sinistrabeculectomy and its variants) and non-perforating (deep sclerectomy). The proposed drainage from chitosan can be used for all types of these operations.

The design of the drainage ensures the optimization of anti-glaucomatous surgery and the normalization of intraocular pressure. The material chitosan was used for the first time, having a number of advantages over other materials:

1) absolute biocompatibility (no cases of chitosan rejection in the tissues of the body, including in contact with blood),

2) the absence of an allergic reaction,

3) the absence of an inflammatory reaction,

4) elasticity and the ability to shape with specified parameters,

5) chitosan has immunomodulating, antimicrobial, fungistatic, anti-inflammatory, hemostatic effects.

DETAILED DESCRIPTION OF THE INVENTION

The form of drainage has design features that provide the advantages of its use in glaucoma surgery.

The drainage is oval. This makes it possible to implant it into the intrascleral canal without subsequent displacement. The serrated edges do not allow to move outward from the intrascleral canal. The general shape does not allow anterior displacement towards the anterior chamber of the eye. The drainage in the cross section has a corrugated shape, which ensures the passage of intraocular fluid. The design of the drainage ensures the optimization of the outflow of intraocular fluid, because, unlike the prototype, it flows not through the microholes, but in the radial direction in the space between the layers of the sclera. Also, this form facilitates the ability to fix it with forceps when it is implanted in the intrascleral pathway. In the middle part of the drainage, there is an increase in the thickness, and, consequently, in elastic properties, which prevents the possibility of closure of the intrascleral canal without damaging both the drainage itself and the surrounding tissues. The elasticity of the chitosan material makes it possible to additionally form the dimensions and shape using a microsurgical instrument (scissors, knife). The drainage is made in the form of a corrugated structure with the possibility of folding, when folded, the structural elements are parallel to each other, the presence of serrated elements along the edges of the drainage is necessary for its fixation in the intrascleral space. Biodegradation occurs gradually, providing an additional therapeutic effect (antimicrobial activity, biostimulation, antioxidant properties), which in case of glaucoma is justified and necessary. Thus, chitosan drainage provides not only the effect of normalizing intraocular pressure, but also an extended therapeutic effect on eye tissue.

Example 1. Patient T., age 61 years. Diagnosis: OD - open-angle uncompensated glaucoma of the initial stage. On the right eye, a non-penetrating deep sclerectomy was performed with intrascleral implantation of chitosan drainage according to the invention. The operation and the postoperative period proceeded without complications. At discharge, the acuity of both eyes remained unchanged, the IOP of both eyes was 18 mm Hg.

Example 2. Patient J., 59 years old. Diagnosis Open-angle uncompensated developed glaucoma. A deep sclerectomy operation was performed with intrascleral implantation of chitosan drainage according to the invention. The operation and the postoperative period proceeded without complications. At discharge, visual acuity unchanged, IOP - 17 mm Hg When viewed 3, 6, 12 months after surgery, visual acuity and intraocular pressure are stable.

Claims (1)

Drainage for the treatment of glaucoma made of chitosan, characterized in that the oval-shaped drainage is made in the form of a corrugated structure with the possibility of folding, is thickened in the middle part and has serrated elements at the edges.