KR100305222B1 - Artificial cornea - Google Patents

Abstract

The present invention prevents the detachment of the artificial cornea from the eyeball of the operator during corneal surgery, and prevents complications such as leakage and necrosis, formation of the graft posterior membrane, inflammation, and endophthalmitis at the junction of the artificial cornea and the recipient cornea. It relates to an artificial cornea.

The failure of the artificial cornea so far can be divided into two types: the defect caused by the inadequate adhesion between the artificial cornea and the surrounding tissue, that is, the structural failure and the functional failure of the scar tissue covering the optics of the artificial cornea. to be.

The present invention comprises an artificial corneal body (1), a cut (3) installed on the top of the main body 1, and a front flange (2) coupled to the upper surface of the cut (3), the artificial corneal body (1) is composed of a cylinder portion 10 inserted into the eyeball and an optical portion 11 exposed on the front surface of the eyeball, and the optical portion 11 is formed with a diameter smaller than the diameter of the cylinder portion 10 The stepped portion 12 is formed at the lower periphery of the optical portion 11, and the support portion 4 supporting the artificial cornea is formed at the lower portion of the cylinder 10, thereby strengthening the coupling between the artificial cornea and the eye and complications. It is effective to prevent the occurrence of.

Description

Artificial cornea {Artificial cornea}

The present invention relates to an artificial cornea and a surgical method thereof, and more particularly, to prevent the artificial cornea from deviating from the eyeball of the operator during corneal surgery, and to prevent leakage, necrosis, and formation of the graft posterior membrane at the junction between the artificial cornea and the recipient cornea. It relates to an artificial cornea which can prevent complications such as inflammation, endophthalmitis and the like.

The cornea can be severely damaged by severe dry eye, such as Stevens-Johnson syndrome, or severe corneal scars or neovascularization due to severe burns, blepharoplasty, or bullous keratopathy.

The damaged cornea can be implanted with the same cornea to restore visual acuity, but allograft transplant surgery has a high probability of failure.

In addition, in cases where other corneas cannot be transplanted or in cases where allogeneic corneal transplantation has failed several times, artificial corneal transplantation is the only alternative to visual recovery.

Until now, there have been many research and development efforts on the material and design of artificial cornea. As a typical artificial cornea, acrylic method was used in the 1950s, and Cardona, which played an important role in the research of artificial corneas in the 1960s. ) Developed and commercialized artificial nuts and bolts of bolt nut type until recently.

Necessity and Importance of Research and Development of Artificial Cornea

end. Technical aspect

In severe dry eyes, corneal burns, blepharoplasty, Stevens-Johnson syndrome, and multiple unsuccessful corneal grafts, allografts are less likely to recover from vision. However, various kinds of artificial corneas researched and developed to date have many problems. Therefore, it is urgent to develop artificial corneas that are recognized for their stability and efficacy not only in Korea but also in foreign countries.

I. economy. Industrial aspect

Artificial corneas are being used as a last resort in various refractory corneal diseases where allografts are impossible to transplant. Currently, there are no commercialized corneas in Korea, and all of them depend on artificial corneas imported from foreign countries such as the US and France. Most of these artificial corneas are patented, so the price is very expensive. In addition, until now, artificial corneas developed in foreign countries have not shown a consistent success rate and are often blinded due to various complications even after repeated reoperations.

All. Social. Cultural aspects

In developed countries, the artificial cornea has been researched and developed only as a treatment for intractable corneal disease, which is difficult for allograft transplantation, but Korea has another reason to develop artificial cornea. In other words, most of the people in our country avoid organ donation after death due to conservative Confucianism, so the donor cornea needed for allograft transplantation is in short supply. to be. Therefore, if more stable artificial cornea is developed, it is expected that rapid corneal recovery and social return of many corneal disease patients will be possible.

The present invention has been made to solve the above problems.

The failure of the artificial cornea so far can be divided into two types: the defect caused by the inadequate adhesion between the artificial cornea and the surrounding tissue, that is, the structural failure and the functional failure of the scar tissue covering the optics of the artificial cornea. to be.

In order to overcome these failure factors, we developed a new artificial cornea by determining the optimal conditions to maximize biocompatibility through research on the design of artificial cornea, surface treatment of optic and support material, surgical method and postoperative treatment. In order to contribute to the localization of high-tech medical devices and to contribute to the improvement of medical technology, we will prove the stability through animal experiments and present basic data for future clinical trials and industrialization.

The present invention for achieving the above object has the following features.

All the indications of artificial cornea are allergic corneal grafts, which are so severe that the corneal scars cannot be maintained or their original shape cannot be maintained. In the present invention, the corneal fixation was designed to adhere to the surrounding tissue using a polyurethane cut having excellent bioconjugation, and at the same time, to fix the artificial cornea inside the healthy sclera. It was.

In addition, by extending the back and forth the cylinder of the optical (optic), we tried to prevent the formation of the fiber membrane on the back of the graft. In addition, conjunctival flaps may be covered in the past to allow stable corneal and biosynthetic bonding during initial wound healing. In some cases, the conjunctiva is also damaged in patients who require actual corneal transplantation. In many cases, the conjunctiva is constricted and may promote tissue softening.

Therefore, the present invention was performed by covering the amniotic membrane in order to promote the stable binding of the artificial cornea and the biosynthesis during the initial wound healing period during artificial corneal surgery.

The amniotic membrane is the membrane surrounding the fetus and its exact role is unknown, but it is known to act as an immunological barrier between the fetus and the mother.

Amniotic membrane is composed of epithelial cells, basement membrane, and epilepsy. The basement membrane and epilepsy are tissue-rich tissues that promote the movement, proliferation, and adhesion of epithelial cells. It was first implanted in the conjunctiva and defect of the conjunctiva in 1940.

In addition, there have been reports of partial reconstruction of corneal surface by implanting human amnion into experimental corneal burn model of rabbit. In the present invention, attempts were made to cover the amniotic membrane after the artificial corneal procedure in order to assist in the wound healing effect of the basement membrane components as well as to stabilize the artificial cornea and the biojunction during the initial wound healing.

In addition, by removing the lens and vitreous body in an effort to suppress the formation of the graft posterior fibrous membrane, a very common complication of artificial corneal graft, the contact between intraocular tissue and artificial cornea was reduced, and anticoagulant heparin was mixed in the perfusion solution.

In addition, we tried topical and subconjunctival injection of steroids to reduce the softening of peri-corneal tissues. Antibiotics were used before and after surgery to prevent endophthalmitis.

1 is an exploded perspective view of the artificial cornea of the present invention

2 is a cross-sectional view showing an artificial cornea of the present invention.

Figure 3 is a cross-sectional view showing a state in which the operation of the artificial cornea of the present invention in the eye

<Explanation of symbols for main parts of drawing>

1. Main body 2. Front flange

3. Cut 4. Support

10. Cylinder 11. Optics

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is an exploded perspective view showing the artificial cornea of the present invention, Figure 2 is a side cross-sectional view showing the artificial cornea of the present invention, Figure 3 is a cross-sectional view showing a state in which the artificial cornea of the present invention operated on the eyeball.

As shown in Figures 1 to 3, the artificial cornea of the present invention is coupled to the artificial corneal body 1, the cut 3 is installed on the upper portion of the main body 1, the upper surface of the cut 3 Is composed of a front flange (2), the artificial corneal body (1) is composed of a cylinder portion 10 is inserted into the eyeball, and the optical portion 11 exposed to the front of the eyeball, the optical portion 11 Is formed to a diameter smaller than the diameter of the cylinder portion 10 to form a step 12 on the lower periphery of the optical portion 11, to form a support portion 4 for supporting the artificial cornea in the lower portion of the cylinder 10 It is composed.

The projectile 12 is formed to be inclined so that the height is lowered toward the outside so that the cut 3 seated thereto may be installed to be curved.

The front flange 2 is also formed to be curved in accordance with the corneal curvature so as to cover the front of the cornea.

The main body 1 is composed of a transparent polymethylmethacrylate (PMMA), and the cut 3 is formed of a polyurethane having a thickness of 0.4 mm and a pore of 40 μm. The front flange 2 is made of pro-silicon (RGP) excellent in oxygen permeability.

In addition, between the front flange (2) and the cylinder (10) and between the optical portion (11) and the cut (3) n-butyl 2-cyanoacrylate (Histoacryl, B. Braun, Melsugen AG) , Germany) and the cylinder (10) and the support (4) was attached by generating heat instantaneously with ultrasonic waves.

The front flange 2 has a diameter of 6 mm and a thickness of 0.2 mm, the cylinder 10 has a diameter of 4 mm and a length of 3.5 mm, and the cut 3 has a front flange of a donut shape having an inner diameter of 6 mm, an outer diameter of 9 mm, and a width of 3.0 mm. Attached to the back side, the support portion (4) attached to the lower portion of the cylinder 10 is formed of two semi-elliptic, so that the total diameter is 11mm.

All artificial corneal parts were sterilized with ethylene-oxide gas.

Referring to the surgical procedure using the artificial cornea of the present invention configured as described above are as follows.

Collection and preparation of amniotic membranes

Placenta from a caesarean mother is washed with physiological saline under a laminar flow hood, and a force is placed in the space between the chorion and the amniotic membrane to remove the amnion from the chorion. Peeled off easily.

The epithelium of the amniotic membrane was stretched upward to the nylon membrane filter, and washed three times with saline mixed with 8ul / cc of gentamicin and 20ul / cc of cefamezine.

The amniotic membrane and the nylon membrane (filter) were cut into 2 cm X 2 cm and the minimum amount of medium (glycerol) and the same amount of glycerol (glycerol) in the same amount of sterling solution and stored in a freezer at -70 ℃ freezer.

During the artificial corneal procedure, it was dissolved at room temperature, soaked in saline mixed with 8ul / cc of gentamicin and 20ul / cc of cefamezine for 30 minutes, and then implanted on the artificial cornea.

-Preparation for Surgery-

Twenty-four healthy white rabbits without eye diseases of 2 to 3 kg were used as experimental animals, and the operation was performed only on the right eye. 0.3% gentamicin eye drops every 3 hours from the day before surgery to reduce the incidence of postoperative endophthalmitis and 3 times with 10% phenylneephrine and 1% tropicamide at 5 minute intervals After instillation, 1 hour later, general anesthesia was performed by intramuscular injection of ketamine (30 mg / kg) and xylazine (4 mg / kg) into the thigh. When anesthesia was broken during surgery, additional xylazine was injected into the muscle.

-Surgery method-

After corneal incision of the cornea, the Plieringa fixation ring was fixed to the sclera with 6-0 black silk.

Peel the epithelium of the cornea with the Beaver blade No. 69 and perform a partial corneal trephination at the center of the cornea with a 6mm diameter corneal trephine. A 69 mm beaver blade was used to make a 360-degree intra-lamellar incision with a 2 mm width to create a corneal pouch into which a polyurethane skirt (3) would later be inserted.

The cornea was excised along a partial corneal round excision using a supersharp blade and corneal scissors. The lens nucleus was removed after making a circular incision through the corneal resection hole. Ocuton was used to inhale the lens cortex and posterior capsular and all vitrectomy was performed. The perfusion solution is 20ul / cc of cefamezine, 8ul / cc of gentamicin, and 1ul / cc of heparin in a balanced salt solution (BSS, Alcon, Fort Worth, Texas, USA). Used by mixing. Fully inject Viscoat (Alcon Surgical, inc., Fort Worth, Texas, USA) into the anterior chamber and 10-0 polypropylene (Prolene, Ethicon, Edinburgh, in the middle of both supports 4 of the artificial cornea). UK), and the artificial cornea is inserted into the eye and sutured and fixed to the ciliary sulcus at 3 and 9 o'clock.

Polyurethane skirt (3) is inserted into a pre-made corneal pocket and sutured with four 10-nylon sutures (Alcon Surgical, Inc., Fort Worth, Texas, USA).

Amniotic membranes immersed in saline mixed with antibiotics were cut round to a diameter of 1.5 cm, removed from a nylon membrane, covered with an artificial cornea, and sutured in a purse-string form with a 10-nylon suture.

After subconjunctival injection of 20 mg of gentamicin and 20 mg of dexamethasone, steroid and antibiotic ointment were put into the conjunctival sac. Subsequently, steroids and antibiotic ophthalmic ointments were placed in the conjunctival sac daily and subconjunctival injection of gentamicin and dexamethasone once every three days for two weeks.

The present invention is not limited to the above embodiments, and various modifications can be made within the scope of the technical idea of the present invention.

The procedure of artificial cornea is considered as a last resort in various refractory corneal diseases where allografts are impossible to transplant. Currently, there are no commercialized corneas in Korea, and all of them depend on artificial corneas imported from foreign countries such as the US and France. Most of these artificial corneas are patented, so the price is very expensive. In addition, most of the artificial corneas developed so far have not shown a consistent success rate, and they have repeatedly undergone repeated reoperations and eventually become fatal complications, resulting in safety and efficacy compared to the enormous cost. Is difficult.

In addition, because most of our people avoid organ donation after death due to conservative Confucianism, the donor cornea needed for allogeneic cornea transplantation is not enough, so many people who can improve their eyesight and normal social life only by allograft transplantation are neglected. to be. Therefore, if more stable artificial cornea is developed, it is expected that many Korean corneal disease patients who are waiting for long-term donation like this without any promise and who are spending their time in blindness can recover their vision and return to society.

Claims (2)

The artificial corneal body 1, the cut 3 is installed on the upper portion of the main body 1, and the front flange (2) coupled to the upper surface of the cut 3, the artificial corneal body (1) Is composed of a cylinder part 10 inserted into the eyeball and an optical part 11 exposed on the front surface of the eyeball, and the optical part 11 is formed to have a diameter smaller than the diameter of the cylinder part 10, thereby providing an optical part ( An artificial cornea, characterized in that to form a step (12) on the lower periphery of the 11, and to form a support (4) for supporting the artificial cornea in the lower portion of the cylinder (10). The donuts of claim 1, wherein the front flange 2 has a diameter of 6 mm and a thickness of 0.2 mm, the cylinder 10 has a diameter of 4 mm and a length of 3.5 mm, and the cut 3 has an inner diameter of 6 mm, an outer diameter of 9 mm, and a width of 3.0 mm. Attached to the back of the front flange (2) in the form, the support portion (4) attached to the rear of the cylinder 10 is formed of two semi-elliptical, the artificial cornea, characterized in that the total diameter is formed to be 11mm.