RU2562541C1 - Method for producing carbon-based fibre drain microtube for ophthalmosurgical operations and carbon-based fibre drain microtube for ophthalmosurgical operations - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: producing a carbon-based fibre drain microtube for ophthalmosurgical operations involves thermal processing of a viscous filament, activation of the produced carbon-based filament in a gas flow and impregnation thereof in a glucose solution. A temperature of the thermal processing of the filament makes 1,700°C. The activation procedure is performed in an air flow at a temperature of 600°C for 45 minutes. The carbon-based fibre drain microtube produced as described above represents a cord of 1,000-1,200 carbon-based filaments of 7-9 mcm in diameter.

EFFECT: using the group of inventions provides stable antihypertensive effect and preserving visual functions in the patients with a developed, advanced and terminal stage of glaucoma, preventing postoperative complications, and reducing intraoperative injuries.

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Description

The present invention relates to medicine, namely to ophthalmology, and can be used to treat primary and secondary glaucoma.

It is known to use drainage from synthetic and polymeric materials (silicone, polyurethane, polypropylene, polytetrafluoroethylene, kapron thread). Currently, in ophthalmology, silicone or polyamide tubes are used in treatment [1]. Silicone and polyamide have several disadvantages and therefore are not widely used. These materials are not biocompatible materials. They are prone to aging and, as a rule, last no more than 10 years. In the future, such properties as cold flow, swelling and rejection are manifested. Despite the rather successful result of surgical treatment, which according to different authors is 25-98%, the development of postoperative complications such as prolonged postoperative hypotension, small anterior chamber syndrome, corneal edema, retinal detachment, uveitis, endophthalmitis, choroidal bleeding, etc.

Known drainage for the surgical treatment of open-angle secondary glaucoma, used by the method of microdraining in the treatment of glaucoma [1]. A scleral tunnel incision is made and one end of a multifilament carbon fiber 20–25 mm long is inserted into the anterior chamber. The other end of the thread is brought into the subtenon space of the eyeball. The disadvantages of the method is the inability to ensure the proper outflow of intraocular fluid from the eye.

Known carbon microdrainage proposed Maximova L.V. in 2000 [2]. An implant in the form of a piece of fibrous tissue with a length of 2.0–3.0 mm and a width of 1.0–1.5 mm, which was cut out of a carbon napkin, was used as microdrainage [2]. The woven carbon fabric is based on activated viscose yarn. Carbon material does not have a general toxic, irritating, sensitizing effect on the body and is highly biocompatible with human tissues.

However, the disadvantages of this analogue include:

- low sorption capacity of carbon fiber;

- inability to ensure proper outflow of intraocular fluid from the eye;

- pronounced fragility and friability of carbon fiber, which complicates the active use of this material as microdrainage.

The closest is carbon microdrainage [3], which is a thread 25-30 mm long, with a diameter of 100-150 microns from carbon fiber cellulose, previously heat-treated at 1000 ° C and activated in a CO ₂ stream at 900 ° C with a carbon dioxide consumption of 20 l / hour, before direct use, the thread should be aged for 1 min in a 40% glucose solution. Microdrainage provides effective removal of fluid from the cavities of the eye.

The objective of the present invention is to develop a method for producing biocompatible, long-lasting carbon drainage, with high functional characteristics, providing drainage of fluid from the bottom of the eyeball in the surgical treatment of glaucoma. For these purposes, carbon fiber obtained from viscose yarn is most suitable. In the practice of carbon fiber production, the parameters of high-temperature processing range from 1000 ° C to 3000 ° C, depending on the field of its application.

In the proposed technical solution, the optimum temperature for producing carbon fiber is 1700 ° C, it is this temperature that provides the goals in terms of density, chemical purity, sorption capacity, strength and other characteristics of the resulting product. Higher temperatures of the final processing of the fibrous material lead to an increase in strength characteristics and inversely to a decrease in the sorption capacity and specific surface of the material. The density of the obtained carbon fiber is 1.4 g / cm ³ , the carbon content is not less than 99.93%, the tensile strength of the tow is not less than 300 MPa. The obtained carbon fiber undergoes surface activation at 600 ° C in an air stream for 45 min, due to this the fiber increases its sorption capacity from 0.7 to 120 cm / g and has a capillary type porosity of up to 200 nm over the entire length of the fiber, the density increases up to 1.84 g / cm ³ . The number of filaments in the fiber microdrain bundle is 1000-1200 pcs., Filament diameter 7-9 microns. Viscose yarn used as a raw material for the production of carbon yarn, proposed by the authors as microdrainage, has a filament diameter of 7–9 μm, which, as the studies show, is optimal. The number of threads in the tow 1000-1200 pcs., Is optimal for complete drainage of the volume of fluid released from the eye, was chosen experimentally. Carbon fiber is transferred from the roving state to the twisted state, which has advantages during surgical operations. Then, the twisted carbon fiber is impregnated in a 40% glucose solution, after which it is hermetically sealed in plastic bags and sterilized by gamma radiation at a dose of 25 Mrad. Sterilization of carbon fiber allows you to achieve the necessary medical purity of the proposed facility.

The technical result when using the invention is a persistent antihypertensive effect and preservation of visual functions in patients with advanced, distant and terminal stages of glaucoma, prevention of postoperative complications, and a decrease in morbidity.

The carbon fiber microdrainage obtained by the proposed solution was used in the surgical treatment of glaucoma at the Moscow Research Institute of Eye Diseases named after Helmholtz Federal Agency for High-Tech Medical Care, as part of a cooperation agreement with NIIgrafit OJSC. After two hours after surgery and the termination of the action of anesthesia, patients are allowed to rise and move freely. In the postoperative period, anti-inflammatory and prophylactic antibacterial therapy is performed. An extract from the hospital is performed on the 5-6th day after the operation. Patients are prescribed the installation of a Diclo-F 0.1% solution, followed by examination after 7 days. Next, they conduct a clinical examination and registration after one, three, six months, one year up to 2.5 years after the operation. The use of the proposed carbon fiber microdrainage is illustrated by the following clinical examples.

Example 1

Patient D., 77 years old, was hospitalized with a diagnosis of open-angle glaucoma IV "C" of the right eye (terminal stage). Concomitant diseases: angina pectoris, coronary heart disease. Complaints about the lack of objective vision for the past six months, vision progressively worsened over the past 3 years, conservatively treated on an outpatient basis, the last year of compensation for intraocular pressure was not observed.

Visual acuity of the right eye: light sensation with the wrong projection of light. With biomicroscopy: destruction of the pupil border, a single rubeosis of the iris. Gonioscopy: the anterior chamber angle is wide, pigmentation is III degree. In the fundus: optic nerve disc gray, glaucomatous excavation, Salus II-III. Tonometry: IOP = 36-42 mmHg Tomography: P ₀ = 34, C = 0.04, P ₀ / C = 850. Field of View: None.

Microdrainage was performed with carbon fiber microdrainage. The postoperative period was uneventful. Observations of the patient are carried out for 2 years after surgery. The result is a long-term compensation of intraocular pressure, a satisfactory outflow of intraocular fluid, which is important for preserving the eyeball and the absence of pain, and ultimately improving the patient's quality of life.

Example 2

Patient Sh., 56 years old, was hospitalized with a diagnosis of open-angle II B glaucoma of the right eye (developed stage of glaucoma). Concomitant diseases: hypertension 11 tbsp., Angina pectoris, coronary heart disease. Complaints of “fog” in front of the right eye at dusk and in the morning, decreased vision of the right eye. Sick for 3 years. Topically received a 0.5% solution of okumeda 2 times a day in the right eye.

During biomicroscopy, pigment spraying along the pupil edge was noted, a symptom of emissary. DZN pale with glaucoma excavation DZN, moderate shift of the vascular bundle to the nasal side. Visual acuity of 0.3 s - 1.0 D = 0.7. Gonioscopy: the iris-corneal angle is wide, the profile is high, the apex is acute, pigmentation is II degree, exogenous. Tonometry: IOP = 28-32 mm Hg Tonography: P ₀ = 28 mm Hg, C = 0.1 mm ³ min / mm Hg, P ₀ / C = 280. Field of view: narrowing of the borders from the nasal side by 10 ° -15 °. Microdrainage was performed with carbon fiber microdrainage. The postoperative period was uneventful.

A day after the operation: moderate conjunctival hyperemia, mainly in the projection of the conjunctival suture, the filtration cushion is well contoured, a black graft is visible in the anterior chamber, the iris is not changed in color, the pupil is round, in the center, it reacts languidly to light. On the 7th day: residual conjunctival injection, conjunctival suture removed, the iris is normally colored, the pupil is round, in the center, actively responds to light. After 3 months: there is no injection of the eyeball, the pupil is round, in the center, responds well to light. After 6 months: the eye is calm, there is no eyeball injection. Observation continued up to 2.5 years.

Information sources

1. Patent of the Russian Federation No. 2385697 dated 02.12.2008, publ. 04/10/2010.

2 “Carbon implant microdrainage in the treatment of primary uncompensated open-angle glaucoma: Abstract. dis ... cand. honey. Sciences, Rostov-on-Don, 2000, pp. 7-9.

3. RF patent No. 2030173 dated 12/30/1999, publ. 06/12/2002.

Claims (3)

1. A method of producing carbon fiber microdrainage for ophthalmic surgery, including heat treatment of viscose-based filaments, activation of the obtained carbon filament in a gas stream and impregnation of it in glucose solution, characterized in that the temperature of the heat treatment of the filament is 1700 ° C, and activation is carried out in air flow at a temperature of 600 ° C for 45 minutes. 2. Carbon fibrous microdrainage obtained by the method according to claim 1, for ophthalmic surgery, which is a bundle of 1000-1200 carbon filaments with a diameter of 7-9 microns. 3. Carbon fibrous microdrainage for ophthalmic surgery according to claim 2, characterized in that it is sterilized in a hermetically sealed form.