Keratoprosthesis

The invention relates to medicine, particularly to ophthalmology, and can be used in ophthalmic surgery to replace the cornea at its opacity varying etiologies.

Known keratoprosthesis (US N 5030230) that contains the optical cylinder (lens) made of different biocompatible synthetic material by casting or polymerization form, such as PMMA, polycarbonates, polysulfones, poliGEMA, silicones, and others, and a supporting plate made of biological materials, such as the cornea, sclera, fascia, tendon, cartilage, bone and other connective tissues. Compound optical cylinder the supporting part is performed by various adhesives, preferably bioadhesives polifenolproteinov type. The authors prefer keratoprosthesis fabric backing plate prior to the manufacture process keratoprosthesis formalin, alcohol, glutaraldehyde and similar substances, to reduce antigenicity, inhibition of vascularization and increase shelf life.

However, the optical connection of the cylinder to the base plate by any of the adhesives do not provide sufficient biomechanical strength of the bond due to significant differences in physicochemical characteristics such components prosthesis materials. During storage, and also after implantation into a patient such keratoprosthesis occur in such cases, the inevitable changes of adhesive (lysis, proteolysis, hydrolysis), significantly reduces the strength of the compound until the collapse of the whole structure. Additionally, all currently known bioadhesives to varying degrees of toxicity and antigenicity.

The object of the invention is to provide a keratoprosthesis having improved strength and biological properties to prevent its rejection.

The technical result is achieved by using keratoprosthesis according to the invention is the prevention of rejection keratoprosthesis due to its more robust construction, a good biocompatibility with the tissues of walleye and rapid accretion of the patient's cornea with a supporting part keratoprosthesis.

The technical result is achieved in that the support and the optical part keratoprosthesis connected directly to each other due to the transition zone of interpenetrating polymer networks of polymers and / or copolymers of the optical parts and biopolymers of natural tissue supporting part, wherein the connection support and the optical part is the physical interpenetration of materials and / or chemical binding of proteins bearing part with polymers and copolymers of the optical part.

The support portion may be made of porous proteinaceous materials obtained by processing of native natural fabrics, which reduces the immune response of the recipient as compared to native tissue.

The optical portion can be made of polymers of ethylenically unsaturated monomers (for example, vinylpyrrolidone, 2-hydroxyethyl methacrylate), copolymers of ethylenically unsaturated compounds with collagen, polymers obtained by polycondensation (for example, polyurethanes, polysulfones, polycarbonates), silicon polymers, and the optical portion can be further It provided with a UV-absorbers, for example benzophenone and / or benzotriazole.

Compound core and the optical portion occurs simultaneously with forming the optical portion, and a direct connection of the optical and support part is achieved thanks to the fact that the monomer mixture by polymerization which is formed by the optical part, initially penetrates to the desired depth in the mesh of natural tissues and / or porous proteinaceous materials obtained by processing natural native tissues, and only then subjected to the polymerization simultaneously with the formation of the optical part. The polymerization of the monomer mixture support portion at the juncture of the optical and support portions formed keratoprosthesis transition zone interpenetrating networks of synthetic polymers and / or copolymers of the optical part and biopolymers, and / or natural porous materials obtained by processing natural native tissues. Further, the optical part, polymerized in the form of a cylinder, grind lathe according to the program, a similar program vytachivaniya intraocular or contact lenses, without prejudice to the support portion, and a transition zone. The optical part is made with the diopter value on the basis of optimal values ​​for maximum visual acuity of the patient.

Implantation of the proposed keratoprosthesis follows. With trephine produce a through trepanation and remove the required diameter of the cornea. Keratoprostheses same size sutured into place remote obvivnym corneal suture. Aseptic dressing.

EXAMPLE 1 Patient C., 35 years old. Diagnosis: vascularized corneal burns walleye.

Visual acuity of the right eye (OD) right light perception.

Visual acuity of the left eye (OS) 0.020 not corr.

Electroretinography: moderate reduction of functions of the retina of both eyes.

On the right eye surgery performed - keratoprosthesis implantation, is: optical part - poly-2-hydroxy (ethyl methacrylate), the supporting part - donor cornea.

Visual acuity after surgery 0.6. The operation and the postoperative period was uneventful. When control inspections throughout the entire period of observation (1 year) keratoprosthesis is the correct way, signs of rejection were observed. Visual functions are stable.

Example 2. Patient K., 47 years old. The diagnosis: a secondary epithelial-endothelial corneal dystrophy, aphakia (OS).

Visual acuity of the left eye (OS) right light perception.

Electroretinography: OI - retinal function in the normal range.

On the left eye surgery performed - keratoprosthesis implantation, is: optical part - poly-N-vinylpyrrolidone, the supporting part - donated sclera. Visual acuity after surgery 0.8. The operation and the postoperative period was uneventful. When control inspections throughout the entire period of observation (1 year) keratoprosthesis is the correct way, signs of rejection were observed. Visual functions are stable.

Example 3. Patient D., 56 years old. Diagnosis: vascularized corneal burns walleye.

Visual acuity of the right eye (OD) right light perception.

Electroretinography: Reduced function of the retina of both eyes.

On the right eye surgery performed - keratoprosthesis implantation, is: optical part - statistical equimolar copolymer of poly-2-hydroxyethyl methacrylate and N-vinylpyrrolidone, equipped with a UV absorber, supporting part - a porous material obtained by defibrillation cornea cattle.

Visual acuity after surgery 0.1. The operation and the postoperative period was uneventful. When control inspections throughout the entire follow-up period (1.5 years) keratoprosthesis is the correct way, signs of rejection were observed. Visual functions are stable.

Example 4 Patient S., 39 years old. Diagnosis: vascular cataract cornea (OD).

Visual acuity of the right eye (OD) right light perception.

Electroretinography: moderate reduction of functions of the retina of the right eye (OD).

On the right eye surgery performed - keratoprosthesis implantation, is: optical part - feniletilsiloksan, the supporting part - a porous material obtained by enzymatic treatment of bovine sclera.

Visual acuity after surgery 0.2. The operation and the postoperative period was uneventful. When control inspections throughout the entire follow-up period (0.5 years) keratoprosthesis is the correct way, signs of rejection were observed. Visual functions are stable.

EXAMPLE 5 Patient S., 65 years old. Diagnosis: vascular cataract cornea (OS).

Visual acuity of the left eye (OS) is correct light perception.

Electroretinography: moderate reduction of functions of the retina of the left eye (OS).

On the left eye surgery performed - keratoprosthesis implantation, is: optical part - polycarbonate, the supporting part - a porous material obtained by enzymatic treatment of pericardial cattle.

Visual acuity after surgery 0.1. The operation and the postoperative period was uneventful. When control inspections throughout the entire observation period (2 years) keratoprosthesis is the correct way, signs of rejection were observed. Visual functions are stable.

Thus, the proposed model keratoprosthesis allows for more comprehensive medical rehabilitation of patients with severe vascular cataracts, to prevent rejection keratoprosthesis improve biological tolerability keratoprosthesis walleye and stabilize tissues obtained after surgery functional effect for a long time.