RU179971U1 - Bioresorbable anti-glaucoma drainage - Google Patents

Abstract

Bioresorbable anti-glaucoma drainage refers to ophthalmology and is intended for the treatment of glaucoma. The drainage is made of a collagen hemostatic sponge and consists of a rectangular part for implantation into the intrascleral canal 3 × 2 mm in size and an annular part for subconjunctival administration with an outer diameter of 10 mm and an inner diameter of 6 mm. Drainage prevents hypotension due to excessive filtration of aqueous humor in the early postoperative period, and prolongs the hypotensive effect of fistulizing anti-glaucoma interventions with a decrease in scarring of the created outflow pathways of the intraocular fluid, and a decrease in the risk of acute and chronic inflammatory reactions.

Description

The proposed utility model relates to ophthalmology and is intended for the treatment of glaucoma. Bioresorbable drainage can be used as a component of fistulizing anti-glaucoma surgery to prolong the hypotensive effect of the intervention by reducing the risk of scarring of the surgical area, as well as to form a metered outflow of intraocular fluid in the early and late postoperative period.

Surgical treatment of glaucoma is to reduce ophthalmotonus by creating additional pathways for the outflow of intraocular fluid. However, often the reason for the lack of a persistent hypotensive effect of the operation is scarring of the surgical area. Risk factors for the development of excessive scarring include the patient’s young age (up to 40 years), intraocular surgery performed up to 3 months, history of ineffective anti-glaucoma surgery, prolonged local hypotensive therapy, postoperative aphakia, inflammatory eye diseases, neovascular glaucoma, traumatic glaucoma . In addition, according to studies, glaucoma is accompanied by a violation of cellular and humoral immunity, degenerative damage of the conjunctiva, sclera and tissues of the drainage system of the eye, a change in the composition of intraocular fluid, and an increase in the intensity of lipid peroxidation. All this contributes to a more pronounced inflammatory reaction, cell proliferation and scarring of the surgical area in the early and late postoperative period.

The use of drains as a component of anti-glaucoma surgery is aimed at reducing the risk of excessive scarring of the created pathways of the outflow of intraocular fluid and providing a stable hypotensive effect of surgical intervention. Currently, bioresorbable drains (Xenoplast, Glautex, OloGen) are widely used. The use of biocompatible materials can reduce the severity of the inflammatory reaction in response to implantation of drainage in the early and late postoperative periods, the gradual resorption of drainage (within 6-12 months) ensures the formation of stable pathways for the outflow of intraocular fluid.

Currently, synthetic polymers derived from dicarboxylic acid esters and natural polymers (collagen, chitosan) are used as a material for bioresorbable anti-glaucoma drains.

Known drainage "Glautex", which is a bioresorbable porous film consisting of polylactic acid (polylactide) and ethylene glycol (Alekseev IB, Dolgiy S.S., Korigodsky A.R., Slonimsky A.Yu. patent RU 126931 from 04/20/2013). The drainage has the shape of a rectangular coupling, its folded thickness is 80 microns, pore diameter 30-50 microns. During trabeculectomy, Glautex is put on a superficial scleral flap, thereby reducing the risk of sclero-scleral and sclero-conjunctival adhesions. Complete resorption of drainage occurs within 4-8 months, while a stably functioning zone of outflow of intraocular fluid is created. The disadvantage of this drainage is its pronounced swelling, which leads, on the one hand, to a decrease in the volume of the intrascleral cavity and a decrease in the outflow of intraocular fluid, and on the other hand, to possible contact with the conjunctiva and eruption with the formation of external filtration of aqueous humor.

Known drainage "Xenoplast" for implantation in the intrascleral space during filtering surgery for glaucoma (Anisimov S.I., Anisimova S.Yu., Anisimova N.S. Patent RU 2585728 dated 06/10/2016) This drainage is 3.0-4.0 mm-1 in size. 5 mm -0.5-0.8 mm, made of highly purified collagen type I of animal origin, saturated with sulfated glycosaminoglycans. The pore size is from 200 to 700 microns. The outflow of intraocular fluid is carried out along the entire length of the drainage, while its swelling is not more than 0.1%. The porous structure provides a dosed outflow of intraocular fluid, and a gradual long-term resorption of drainage (within 12 months) reduces the risk of scleroscleral scarring. A serious disadvantage of Xenoplast drainage is the lack of prevention of the formation of sclero-conjunctival adhesions, leading to encapsulation of the filter pad, a decrease in the outflow of intraocular fluid and an increase in intraocular pressure. In addition, prolonged resorption of drainage may be a risk of an immune reaction in the long-term postoperative period.

Known bioresorbable drainage "OloGen" (OculusGen Biomedical Inc. Taipei, Taiwan), which has a cylindrical shape and is a porous matrix consisting of 1% collagen and chondroitin-6-sulfate. The diameter of the drainage is 6-8 mm, the thickness is 4 mm, the pore size ranges from 20 to 200 microns. “OloGen” was developed for implantation in trabeculectomy on a scleral flap in order to prevent sclero-conjunctival scarring in the postoperative period. The porous matrix provides a dosed outflow of intraocular fluid in the early postoperative period, reducing the risk of hypotension with the development of complications such as ciliochoroid detachment and lens opacification (Sarkisian, 2010). The disadvantage of this drainage is its cylindrical shape, which does not allow the use of this drainage as an intrascleral implant in order to reduce the risk of sclero-scleral adhesions. In addition, OloGen does not contain medicinal substances with antibacterial and antiseptic effects, which can reduce the local acute inflammatory reaction that occurs in response to implantation of drainage.

The closest analogue of the proposed utility model is a bioresorbable anti-glaucoma drainage device made of a biocompatible material (collagen, stabilized hyaluronic acid, copolymers of acrylic monomers with collagen) and used for the surgical treatment of glaucoma (Kozlova T.V. RU 2160574 from 12.20.2000). The author of this drainage was developed for use in non-penetrating deep sclerectomy. It consists of a rectangular working part implanted in the intrascleral space, perpendicular to the limb, in place of the removed deep scleral flap and a V-shaped supporting part located on the surface of the sclera in the subconjunctival space. The outflow of intraocular fluid is carried out from the intrascleral space through a drainage device under the conjunctiva. The author notes that the length of the supporting parts can vary from 4 to 18 mm, the angle of departure of the supporting parts from the working varies from 30 to 160 °. The disadvantage of this drainage is the V-shape of the supporting part, which does not fully impede sclero-conjunctival scarring. In addition, the description does not indicate the use of a drainage device in penetrating glaucoma surgery.

Thus, the task of developing a utility model is to further improve the design of a bioresorbable anti-glaucoma drainage device.

The technical result of the proposed utility model is the prevention of hypotension due to excessive filtration of aqueous humor in the early postoperative period, and prolongation of the hypotensive effect of fistulizing anti-glaucoma interventions with a decrease in scarring of the created pathways of the outflow of intraocular fluid, and a decrease in the risk of acute and chronic inflammatory reactions.

The technical result is achieved through the use of drainage of complex design made of a hemostatic sponge and represented by a rectangular intrascleral part and an annular subconjunctival part.

As a bioresorbable material, a hemostatic sponge was used, which includes collagen (98%), boric acid (1.25%), furatsillin (0.75%) (P N001656 from 08.08.2008). High biocompatibility of collagen reduces the severity of the inflammatory response in response to implantation of drainage in the early and late postoperative periods. Boric acid has an antiseptic effect, coagulating proteins of the microbial cell and disrupting the permeability of the cell wall. Furatsillin, being an antibacterial agent, is active against gram-positive and gram-negative flora (Staphylococcus spp., Streptococcus spp., Shigella dysenteriae, Shigella flexneri, Shigella boydii, Shigella sonnei, Escherichia coli, Clostridium perfringpp, fungus, Salmon.

The design of the drainage allows it to be used for implantation simultaneously into the intrascleral canal and subconjunctival. The rectangular intrascleral part has a length of 3 mm and a width of 2 mm and fills the scleral canal along its entire length. The subconjunctival part has an annular shape, the inner diameter is 6 mm, the outer diameter is 10 mm (Fig.). The configuration of the drainage provides directional filtration of intraocular fluid from the anterior chamber under the conjunctiva and reduces the risk of scleral and sclero-conjunctival scarring. Drainage is obtained from a collagen hemostatic sponge by cutting with a trephine.

Due to the porous structure, a dosed outflow of intraocular fluid is provided in the early stages after anti-glaucoma surgery, the risk of eyeball hypotension is reduced. The subconjunctival part of the drainage in a hydrated state increases the height of the cavity of the filtration Pillow, prevents sclero-conjunctival scarring along its periphery and in the central zone. In addition, its configuration reduces the risk of eruption of the drainage through the conjunctiva with its pronounced swelling with the formation of external filtration of aqueous humor.

Gradual resorption of the proposed drainage occurs within 6-8 months, at which time stable pathways of the outflow of intraocular fluid are formed.

This utility model can be used in penetrating glaucoma surgery.

The design of the drainage is shown in the Figure, where 1 is the intrascleral part of the drainage of a rectangular shape (length 3 mm, width 2 mm), 2 is the subconjunctival part of the annular shape (inner diameter 6 mm, outer diameter 10 mm). The drainage thickness is 1.5 mm.

Drainage is used as follows. After the formation of a conjunctival flap, a trabeculectomy is performed through the limbal microtunnel with the help of Punch Kelly. Then bioresorbable drainage is implanted in such a way that the intrascleral part is located in the formed canal, and the subconjunctival part is located under the conjunctival flap.

We conducted experimental work on 7 chinchilla rabbits (14 eyes). All rabbits underwent penetrating anti-glaucoma surgery with implantation of bioresorbable drainage. Ophthalmoscopically there were no signs of local irritant or toxic effects throughout the observation period. Animals were withdrawn from the experiment on days 7-30-60-90. A histological study of the obtained biopsy specimens showed a mild inflammatory response on day 7. after surgery and the absence of signs of a cellular reaction for 30-60-90 days. after surgery, which indicates a high biocompatibility of the drainage. By 60 days. after implantation, complete drainage resorption and narrowing of the intrascleral canal, the appearance of loose connective tissue in its lumen were noted. However, the path of the outflow of intraocular fluid into the subconjunctival space was maintained. After 90 days. after the operation, the intrascleral canal was partially filled with loose connective tissue, the path of the outflow of aqueous humor to the subconjunctival space was visualized. It should be noted that given the severity of the scarring process in animals, the results of a period of 90 days. after penetrating anti-glaucoma surgery on a rabbit’s eye, they can be extrapolated for 1 year of observation after a similar operation performed by humans. Thus, the obtained data in the experiment indicate the safety and high efficiency of the use of drainage in glaucoma surgery.

Example 1

Patient G., 75 years old, diagnosis: OD Primary open-angle glaucoma IIIC, artifact. Visual acuity 1.0 s corr., Intraocular pressure (according to Goldmann) 30.0 mm Hg The patient underwent trabeculectomy with implantation of bioresorbable drainage into the intrascleral canal and under the conjunctiva. The operation and the postoperative period without complications. A decrease in intraocular pressure (according to Goldmann) on the 7th day to 6.4 mm Hg was achieved. After 6 months after the intervention, intraocular pressure (according to Goldmann) 8.6 mm RT. St. without antihypertensive regimen, after 12 months - 1.3 mm Hg without antihypertensive regimen. Data from morphofunctional studies (static perimetry Humphrey, confocal laser scanning ophthalmoscopy) state of the optic nerve without negative dynamics. According to optical coherence tomography of the filter cushion zone by 12 months. of observation, complete resorption of the drainage was noted, while the height of the cavity of the filtration pad did not change; there were no signs of scarring in the area of the intrascleral canal and subconjunctival space.

Example 2

Patient Sh., 59 years old, diagnosis: OS Primary open-angle glaucoma IIC. Visual acuity 1.0 s corr., Intraocular pressure (according to Goldmann) 33.4 mm Hg The patient underwent trabeculectomy with implantation of bioresorbable drainage into the intrascleral canal and under the conjunctiva. The operation and the postoperative period without complications. On the 7th day after the operation, a decrease in intraocular pressure (according to Goldmann) to 11.1 mm Hg, visual acuity of 1.0 s corr. After 6 months after the intervention, intraocular pressure (according to Goldmann) 18.0 mm Hg, visual acuity 1.0 s corr., after 12 months. - 16.3 mm Hg, visual acuity 1.0 s corr. Data from morphofunctional studies (static perimetry Humphrey, confocal laser scanning ophthalmoscopy) state of the optic nerve without negative dynamics. According to optical coherence tomography of the filter cushion zone by 12 months. The observation showed complete resorption of the drainage, a slight decrease in the height of the cavity of the filter pad, there are no signs of scarring in the area of the intrascleral canal and subconjunctival space.

Thus, the porous structure of the drainage provides a metered directed outflow of intraocular fluid from the anterior chamber into the subconjunctival space, preventing excessive filtration, leading to the development of a shallow anterior chamber syndrome and ciliochoroidal detachment in the early postoperative period. The intrascleral part of the drainage reduces the risk of scleral scarring. The subconjunctival part of the drainage in a hydrated state increases the height of the cavity of the filtration cushion, prevents sclero-conjunctival scarring along its periphery and in the central zone. The proposed configuration of the annular part of the drainage reduces the risk of eruption of the drainage during its pronounced swelling with the formation of external filtration of aqueous humor. Gradual resorption of drainage contributes to the formation of persistent pathways of outflow of aqueous humor in the late postoperative period and in long-term follow-up. The high biocompatibility of collagen drainage, as well as the presence of boric acid and furatsillin in its composition, hinders the local inflammatory response in response to its implantation.

Claims (1)

Bioresorbable anti-glaucoma drainage, characterized in that it is made of a collagen hemostatic sponge and consists of a rectangular part for implantation into the intrascleral canal 3 × 2 mm in size and an annular part for subconjunctival administration with an outer diameter of 10 mm and an inner diameter of 6 mm.

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