RU2434614C2 - Explantodrainage for antiglaucoma surgery - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to medicine, ophthalmology and can be used as drainage for surgical treatment of refractory glaucoma. Explantodrainage presents 10-20 mcm thick track membrane from polyethylene terephthalate or polycarbonate, irradiated by heavy charged particles and processed by ultraviolet irradiation and chemical etching in water solution of sodium hydroxide until through canals with 0.3-0.4 mcm diameter are obtained. Superficial layer of membrane is nanostructured by processing in oxygen-containing medium.

EFFECT: explantodrainage makes it possible to preserve formed during antiglaucoma operation intrascleral cavity, achieve high level of biocompatibility, filtering ability, areactivity with minimum of complications, reduce adsorption of blood cells, proteins and other constituents of intraocular fluid on drainage surface.

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Description

The invention relates to medicine, namely to ophthalmology, and can be used for the surgical treatment of refractory glaucoma, which is the most intractable nosological form.

Unsuccessful attempts at antiglaucomatous operations, as a rule, are the result of proliferation of connective tissue and blocking of the surgically formed outflow pathways by the processes of the ciliary body, the root of the iris, fragments of the vitreous body, blood, and crystalline masses. Long-term preservation of surgically formed outflow paths is ensured by implantation of various drainages. By now, the disadvantages of various materials used as drainage are already obvious. Autodrainages (drainage from the patient’s tissues), allodrainages (from the donor’s tissues) soon undergo organization with the formation of a coarse connective tissue capsule impermeable to intraocular fluid [Fedorov et al., Sat. scientific ISTC articles “Eye Microsurgery”. - M., 1989. - S. 47-50; Sokolovsky G.A. et al., 6th All-Union Congress of Ophthalmologists. - M., 1985, T. 2. - S.204-205 .; Smirnov V.P. et al. Ophthalmosurgery. - 1995. - N.1. - p.24; Strampelli B. Valvo, Am. J. Ophthalmol. - 1967. - Vol. 64. - P.371]. Xenodrainages (from animal tissues) cause a pronounced local reaction of the surrounding tissues of the eye, due to the immuno-allergenic effect of foreign tissue [Cherkunov BF, Transactions of Kuybyshevsky honey. Institute. Questions of glaucoma .-- Kuibyshev, 1969 .-- V. 55. - S.181-185; Woltman S.R., J.B. Zippincott Company, - 1980. - P.181-185; Schnayder et al., 101 Congress de la societe Francaise d′ophtalmologie. - Mai, 1995. - P.9].

To date, the most widespread drainage from polymer materials of medical grade purity [Cheglakov Yu.A., Dis. Doct. honey. Sciences.- M., 1989, Krupin T., Am. J. Ophthalmol. - 1980. - Vol. 89. - P.338-343; Molteno, Austr. J. Ophthalmol. - 1985. - Vol.13. - N.4. - P.329-335].

Closest to the proposed in its design is a porous membranous drainage from a nuclear membrane based on lavsan, with a pore diameter of 0.05-2.0 μm, a thickness of 10 μm [RU 2089149 C1, 09/10/97. Saprykin P.I. et al. A method for the treatment of secondary glaucoma].

However, this material has the following disadvantages:

1) protein, blood elements, exudate are adsorbed on its surface, which lead to clogging of pores in the drainage;

2) a dense connective tissue capsule is formed around the drainage in a month [Ryazantseva T.V., Dis. Cand. honey. sciences. - Samara, 1997].

According to our clinical observations, in the long term (after 3-5 years), the lumen between the drainage and the fibrous-altered capsule surrounding it is blocked, which leads to an increase in intraocular pressure and the need for repeated surgery.

We are the first to propose the implementation of explant drainage from nanostructured polymer track membranes made of polyethylene terephthalate or polycarbonate.

The technical result of the invention is that due to the chemical composition and topography of the surface layer, the structure of the pores, the drainage retains intrascleral cavities formed during the anti-glaucomatous operation for a long time, has a high level of biocompatibility, and allows its long-term presence in the eye under conditions of minimal intra- and postoperative complications.

The technical result is achieved in that the drainage is made of a nanostructured membrane of polyethylene terephthalate or polycarbonate with a thickness of 10-20 microns. The membrane is nanostructured as follows:

1) is irradiated with heavy charged particles;

2) is processed by ultraviolet radiation;

3) is subjected to chemical etching in an aqueous solution of sodium hydroxide to obtain through channels with a diameter of 0.3-0.4 microns;

4) in order to hydrophilize the surface of the drainage and increase its porosity, it is processed in an oxygen-containing plasma (air, oxygen, a mixture of oxygen and nitrogen) [Elinson V.M. et al. // Proceedings of the IV International Symposium on Theoretical and Applied Plasma Chemistry. Ivanovo, May 13-18, 2005, T.2, S.346-349, V. Elinson et al. // Mater. conf. “Vacuum Science and Technology”, 2002, p. 384-389].

Figure 1 presents a view of the track membrane, on which the formed holes are clearly visible.

An increase in the content of carboxyl groups in the surface layer of the film, causing an increase in negative charge, as well as the development of surface roughness leads to an additional positive result of the proposed technical solution - a decrease in the adsorption of proteins, other components of intraocular fluid and blood cells, and the absence of the formation of a coarse connective tissue capsule around the drainage. This result is due to the repulsion of protein molecules, which also have a negative charge. Figure 2 presents electron micrographs of the surfaces of the original polyethylene terephthalate track membrane (a) and the membrane processed in an oxygen-containing plasma (b). Figure 3 presents a General view of the drainage.

Thus, the claimed drainage due to nanostructuring has several important advantages:

1) does not adsorb protein, blood elements, exudate, which eliminates clogging of pores in the drainage;

2) the formation of a coarse connective tissue capsule does not occur around the drainage, which in the long term after the operation eliminates the blockage of the outflow of intraocular fluid and an increase in intraocular pressure.

Experimental Examples

Example 1. In a rabbit of chinchilla breed, 2 years old, weighing 3 kg, secondary glaucoma was simulated by introducing a 1% Janus green solution into the anterior chamber of the eye. Secondary glaucoma developed after 1 month.

Before the operation, an ophthalmoscopy was performed daily in direct and reverse light, tonometry with a 10-gram load of Maklakov tonometer in both eyes. The average intraocular pressure reached 28.8 ± 3.1 mm RT. Art. The presence of signs of glaucoma has given rise to an antiglaucomatous operation with implant drainage implantation from a nanostructured polycarbonate membrane.

On the first day after surgery, intraocular pressure was 20 ± 1.2 mm Hg. Art., signs of inflammation were absent. 3 days after surgery, intraocular pressure (IOP) was 21 ± 1.3 mm Hg. Art., there were signs of an inflammatory reaction and on a scale of L.S. Chabrova corresponded to 0 and 1 degrees of inflammation. A mild inflammatory reaction completely stopped on day 5 against the background of standard anti-inflammatory treatment. Further, the pressure was measured after 2 weeks, 1 month and 2 months after surgery. The following IOP indicators were noted, respectively, in terms of: 20 ± 1.5 mm Hg. st .; 20 ± 1.1 mmHg. st .; 21 ± 1.4 mmHg. Art. During a morphological study of the eyes, two weeks later, in the perifocal zone around the drainage, the formation of soft fibers infiltrated by single segmented white blood cells and a significant number of fibrocytes and fibroblasts was revealed. Between drainage and loose fibrous structures, slit-like spaces were clearly defined.

After 3 months, a slit space was determined between the scleral flap and drainage. Reactive inflammatory changes were absent in the tissues surrounding the implant; no signs of drainage biodegradation were found.

Example 2. In a rabbit of chinchilla breed, 2 years old, weighing 2.5 kg, secondary glaucoma was simulated by introducing a 1% Janus green solution into the anterior chamber of the eye. Secondary glaucoma developed after 1 month. Before the operation, an ophthalmoscopy was performed daily in direct and reverse light, tonometry with a 10-gram load of Maklakov tonometer in both eyes. The average intraocular pressure reached 29.8 ± 3.2 mm Hg. Art. The introduction of a 1% solution of Janus green into the anterior chamber of the eye led to the development of secondary glaucoma within one month. The presence of signs of glaucoma provided the basis for an anti-glaucomatous operation with implant implant drainage from a nanostructured polyethylene terephthalate membrane. The operation went without complications.

In the first day after surgery, intraocular pressure was 19 ± 1.3 mm RT. Art., signs of inflammation were absent. 3 days after surgery, the IOP was 20 ± 1.3 mm Hg. Art., signs of an inflammatory reaction on a scale of L.S. Chabrova corresponded to 1 degree of inflammation. A mild inflammatory reaction completely stopped on day 6 against the background of standard anti-inflammatory treatment. Further, the pressure was measured after 2 weeks, 1 month, 2 months and 6 months after surgery. The following IOP indicators were noted, respectively, in terms of: 19 ± 1.8 mm Hg. st .; 21 ± 1.7 mmHg. st .; 20 ± 1.3 mmHg. Art; 19.0 ± 2.1 mmHg Art.

After 6 months after surgery on histological preparations of this series of experiments, loose fibrous connective tissue structures were revealed around the implant. Clearly defined the free space between the scleral flap and drainage throughout. No morphological signs of inflammation were noted.

Clinical examples.

Example 3. Patient F., 67 years old. Preoperative diagnosis: - O / C III with operated glaucoma of the right eye, O / C II and glaucoma of the left eye. A history of glaucoma for 10 years. Antiglaucomatous surgery on the right eye was performed 1.5 years ago. At the time of admission, the patient instilled antihypertensive drugs that did not have a positive effect. On admission: visual acuity of the right eye - 0.6 does not correct, with perimetry revealed a tubular field of view, IOP - 35 mm RT. Art. The operation was performed: deep sclerectomy with intrascleral implantation of drainage from a nanostructured polycarbonate track membrane. The operation and the postoperative period were uneventful. At discharge, visual acuity - 0.8 does not correct, IOP - 17 mm RT. Art. When viewed through 3, 6, 12 months after surgery, visual acuity and IOP are stable - 17.19.19 mm Hg. Art., the field of view expanded by 10 degrees from the fixation point. The data of ultrasound biomicroscopy and optical coherence tomography confirm the presence of free space between the drainage and the scleral flap, i.e. the safety of newly formed pathways of the outflow of intraocular fluid.

Example 4. Patient T., 59 years old. The diagnosis on admission is secondary decompensated uveal glaucoma, complicated cataracts in both eyes. Visual acuity of both eyes - 0.2, does not correct. Intraocular pressure (IOP) of the right eye - 39 mm RT. Art., IOP of the left eye - 37 mm RT. Art. A history of IOP elevation for 1-1.5 years. Instills antihypertensive drugs (ocupress 0.5% 2 times a day). Against the background of drug therapy, IOP of both eyes is not compensated. An operation was performed on the right eye: non-penetrating deep sclerectomy with intrascleral implantation of drainage from a nanostructured polycarbonate track membrane. After 2 weeks, a similar operation was performed on the left eye. Operations and the postoperative period were uneventful. At discharge, the acuity of both eyes remained unchanged, the IOP of both eyes - 18 mm RT. Art. When viewed 6 months after surgery, the IOP remains compensated and amounts to 18-19 mm RT. Art. Against the background of normalized IOP, cataract was removed after 3 months with implantation of an intraocular lens. When viewed after 1 year, the acuity of both eyes is 0.6-0.7. IOP of both eyes - 20 mm RT. Art. The data of ultrasound biomicroscopy and optical coherence tomography confirm the presence of an extensive intrascleral cavity with clearly visualized drainage.

Thus, the data obtained by us from experimental studies and clinical observations clearly indicate the advantages of explant drainage from nanostructured polymer track membranes.

Explant Drainage:

1) does not adsorb protein, blood elements, exudate, which eliminates clogging of pores in the drainage;

2) the formation of a coarse connective tissue capsule does not occur around the drainage, which in the long term after the operation eliminates the blockage of the outflow of intraocular fluid and an increase in intraocular pressure.

Claims (1)

Explant drainage for antiglaucomatous interventions, which is a track membrane of polyethylene terephthalate or polycarbonate, characterized in that the surface layer of the membrane is nanostructured by treatment in an oxygen-containing plasma.

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