medical term
1 Definition: Artificial eye, commonly known as artificial eye, is an eye prosthesis that cannot restore the vision of patients.
2 note:
(1) Artificial eye is a special term in ophthalmology, which is rarely used in other departments.
(2) Even if the patient wears an artificial eye, it is only decorative and cannot help the recovery of vision! (Only the surface looks the same as the normal eye shape)
(3) Patients with artificial eyes have to have their eyeballs removed for various reasons.
(4) With the current level of science and technology, there is no way to restore the vision of patients whose eyeballs have been removed.
Nowadays, artificial eye materials emerge one after another, such as glass artificial eye, polymer artificial eye, crystal artificial eye and so on. Polymer artificial eye is the most widely used. According to authoritative statistics, more than 95% countries in the world now use polymer materials to customize artificial eyes. Materials such as glass artificial eyes and ceramic artificial eyes have been gradually eliminated by the market. .
Two different materials
macromolecule
Polymer is the most widely used artificial eye material in the world. Polymer materials are made in China and imported. Domestic polymer artificial eyes have poor prognosis because of their low price. After wearing 1-2 years, the stability of the material gradually disintegrated, and the inside of the artificial eye gradually showed signs of bursting and yellowing, and finally broke. As the name implies, imported polymer artificial eyes are usually imported from abroad. At present, the best imported polymer raw materials on the market come from Germany and Japan, whose molecular structure is completely different from that of domestic polymers, which is expensive and has a good prognosis. The imported polymer artificial eye has high technology content, and its biggest advantage is easy modification and high simulation. It is not easy to fade and yellow, and its service life can reach 15 years or even 20 years. The disadvantage is also because of its material characteristics, which leads to complex processing technology and high raw material cost.
Artificial organs are the main development direction of medical polymer materials. At present, artificial organs made of polymer materials have been implanted into human body, including artificial kidneys, artificial blood vessels, artificial heart valves, artificial joints, artificial bones and plastic materials. The main polymer materials used are PVC, ABS, PP, silicone rubber, fluoropolymer and so on. There are artificial hearts, artificial lungs, artificial pancreas, artificial blood and artificial eyeballs under study.
The research of medical polymer materials has a history of more than 40 years. From 65438 to 0949, the United States first published a prospective paper on medical polymers. This paper introduces the clinical application of polymethylmethacrylate as human skull and joint and polyamide fiber as surgical suture for the first time. According to incomplete statistics, as of 1990, more than 30,000 academic papers and patents on medical polymers have been published in the United States, Japan and Western Europe. It is predicted that 2 1 century medical polymers will enter a new era. Except the brain, all parts and organs of the human body can be replaced by polymer materials.
In the 2 1 century, which pays more attention to human health, medical polymer materials will play an increasingly important role. The research and development of biomedical materials has also been highly valued by relevant state departments. The national key basic research and development plan ("973") in the Tenth Five-Year Plan and the Eleventh Five-Year Plan has established biomedical materials research projects. The future development of biomedical materials must be from simple use to purposeful design and synthesis, so as to obtain materials with good biocompatibility and biological functionality needed by life. Biomedical engineering and polymer materials and engineering majors in colleges and universities also offer compulsory and elective courses for biomedical polymer materials.
Medical polymer materials can be roughly divided into two categories: external use and internal use. External materials are mainly used to prepare medical supplies, such as infusion bags, infusion tubes and syringes. These polymer materials are widely used because of their low cost and convenient use. Materials used in human body can be divided into surgery and internal medicine. Surgery includes artificial organs, medical adhesives and plastic materials. Polymer drugs are mainly used in internal medicine. The so-called polymer drug is a drug with low molecular weight and polymer carrier, which has the characteristics of long-term and stability.
Features:
1, eyeball atrophy can be worn directly.
Patients with ocular atrophy should pay attention to two points when wearing artificial eye patch.
First, the degree of atrophy of the affected eye and the convexity of the cornea. There is a hard condition for patients with eyeball atrophy to wear artificial eye tablets, that is, the eyeball must be fully atrophied. Usually, the degree of eyeball atrophy needs to reach 60%-70% of that of healthy eyes. Because the prosthetic eye is attached to the affected eye, as long as the eyeball of the affected eye can rotate, the prosthetic eye piece can be driven to rotate synchronously.
Second, the sensitivity of cornea. Under normal circumstances, unless the eyeball is severely atrophied, the cornea wearing the artificial eye piece will contact with the artificial eye piece. If the cornea of the patient's eye is particularly sensitive, the forced wearing of the artificial eye will cause tears, pain, and inability to open the eyes. In this case, before customizing the patient, the patient is usually put on a test piece to understand the sensitivity of the cornea of the affected eye. If you can open your eyes naturally in about half an hour, you can be sure that the affected eye can accept the natural stimulation brought by the artificial eye film, that is, the conditions for customizing the artificial eye are met.
The requirements of customized artificial eyes for patients with ocular atrophy are much higher than those for patients with enucleation. In this case, the customized artificial eye piece not only requires the artificial eye technician to have excellent customization technology, but also puts forward higher requirements for the thickness and material of the artificial eye.
2. No orbital implant was implanted after enucleation.
After enucleation, there is no artificial eye table implanted, and the activity of wearing artificial eye tablets directly is poor.
3. Eyeball enucleation and orbital implant.
Orbital implant is an alternative implant for plastic surgery after enucleation. The exercise effect after artificial eye implantation depends on the adjustment ability of the patients' periocular muscles. Because the orbital implant is stitched to the eye muscle. If the eye muscles have good adjustment ability, the artificial eye table will drive the artificial eye to rotate, and the artificial eye will exercise better.
Advantages:
1, unbreakable. The biggest difference between polymer artificial eye and traditional glass artificial eye is that the material is stable and not easy to break. Especially for children's artificial eye wearers, their autonomy is poor, even if the artificial eye piece falls to the ground, it will not break, while the glass artificial eye material is very brittle and will break when it is slightly hit.
2, the modification is convenient. The elasticity of eye tissue is constantly changing, especially after surgery and wearing artificial eyes for the first time, the affected eye tissue changes greatly. After the swelling is eliminated, the space of conjunctival sac will increase, but the size of the artificial eye piece will not change, which causes the problem that the artificial eye piece is getting smaller and smaller. Polymer artificial eye has strong plasticity, and its size can be modified continuously to adapt to the change of conjunctival sac shape after molding. However, the traditional one-step artificial eye can not modify its size, and it will lose its simulation when worn.
3. Light weight. It is an axiom of ophthalmology that the total mass of the artificial eye table and the artificial eye piece should not be greater than 5g (the weight of the artificial eye table is about 3g at present). Overweight eye prosthesis will lead to lower eyelid relaxation, eyelid ectropion and automatic slide of eye prosthesis after long-term wearing. At present, the customization technology of polymer artificial eye is more and more advanced. There used to be an eye prosthesis customization organization in Shanghai, which could control the weight of polymer eye prosthesis tablets below1g. The wearing comfort of the artificial eye is greatly improved.
4. Strong simulation. After treatment, the polymer artificial eye can reduce the reflectivity of direct sunlight. So that the worn polymer artificial eye has good biological simulation. However, the surface of the traditional glass artificial eye is too smooth, which reflects light seriously under strong light, so it is easy to see the difference under strong light after wearing it. In many aquariums in China, the original glass curtain wall has been replaced by polymer materials, which is one of the reasons to reduce the reflection of materials.
5, strong versatility. Patients with enucleation and atrophy of eyeball need to wear artificial eye tablets. The traditional artificial eye is too thick to meet the needs of patients to keep the eyeball, and the thick artificial eye piece can not be worn on the surface of the affected eye. The polymer artificial eye is easy to process and can be processed into ultra-thin artificial eye, which is suitable for patients with eyeball retention and solves the problem of wearing eyeball retention artificial eye tablets directly.
Soft artificial eye
Using hydrogel materials, you may be a little unfamiliar with hydrogel materials. Essentially, the material used to make contact lenses is hydrogel. Soft artificial eyes are essentially "bigger and thicker contact lenses". Only when hydrogel is used as the material of artificial eye, the biggest advantage is that it brings less stimulation to the eye cavity, and the cheap material reduces the cost of customization. The disadvantage is that the customized prosthetic eye made of this material is easy to fade and has poor simulation, which can be easily seen from healthy eyes. In addition, hydrogel has certain water absorption. Wearing contact lenses for a long time can cause dry eyes. Wearing a soft artificial eye will also dry up the water in the eye cavity. Make the eye cavity dry and reduce the wearing comfort.
Advantages of soft artificial eye:
1. Patients can easily adapt to soft artificial eyes.
Patients without enucleation can try to wear soft artificial eyes. However, conventional hard artificial eye tablets need a certain adaptation period for patients with enucleation. A considerable number of patients' corneas are sensitive and unable to adapt to the stimulation caused by hard artificial eyes, which leads to the inability to wear hard artificial eyes. Compared with the traditional hard artificial eye, the hydrogel soft artificial eye tablet can adapt quickly when it is worn for the first time.
2. The customization cost of soft artificial eye is low.
Soft eye customized price 200-300 yuan. Compared with the customized price of hard artificial eye, the customized cost of soft artificial eye is very low.
Disadvantages of soft artificial eye:
1, the simulation and comfort of soft artificial eyes are poor.
At present, this kind of hydrogel material has poor coloring ability and is easy to fade, so the simulation of soft artificial eyes is not satisfactory and it is easy to distinguish from healthy eyes. In addition, wearing a soft prosthetic eye is easy to absorb water in the eye cavity and on the eyeball, making the affected eye dry. It is easy to cause sclera congestion and redness, which reduces the comfort of wearing.
2, the service life is short
Soft artificial eyes are easy to fade because of the material. When the color of the artificial eye piece fades to a certain extent, the artificial eye has no simulation at all. This regression period is generally 1-2 years.
Classification of soft artificial eyes:
Conventional soft artificial eye:
Patients with atrophy of eyeball or transparent cornea can wear soft artificial eyes directly without enucleation, thus improving the quality of life.
After enucleation, patients with artificial eye socket can wear soft artificial eye tablets directly without punching holes.
Patients who can't wear hard artificial eyes can try wearing soft artificial eyes.
2) cosmetic corneal lens:
Corneal plaque, people with decreased vision can wear full coverage "cosmetic corneal lens".
Patients with marginal corneal plaque and partial vision can wear "cosmetic corneal lenses" with transparent central area.
Because of the adhesion of iris to corneal plaque, surgical patients who have undergone optical iridectomy in the peripheral part should choose "cosmetic corneal lens" with peripheral window opening.
3) Ultra-thin soft artificial eye:
Ultra-thin soft artificial eye, the thickness is about 1.5 mm, and ultra-thin artificial eye tablet [artificial eye] simulates hydrogel, which brings good news to patients with moderate atrophy of eyeball. Because wearing conventional soft artificial eyes is a bit thick, wearing cosmetic corneal lenses, the eyelids are not wide, and the ultra-thin hydrogel soft artificial eyes can achieve the effects of symmetrical eyes and beautiful eyes.
Glass artificial eye
Sodium hexafluoroaluminate (Na3AlF6), namely artificial cryolite, is the main raw material for making glass artificial eyes. Sodium hexafluoroaluminate is mainly used as flux for aluminum electrolysis, wear-resistant filler for rubber and grinding wheel, and enamel whitening agent. Taking cryolite as the raw material, many artificial eye customization institutions will call it "glass artificial eye". Glass artificial eyes have the advantages of high luster and high finish after fire polishing. The disadvantage is that the gloss is too high, which leads to serious reflection of glass artificial eyes under strong light and poor simulation. Secondly, cryolite determines the weight of glass prosthesis. The "thinness" of artificial eye tablets has always been the goal pursued by major eye customization institutions. It is an axiom of ophthalmology that the total mass of the artificial eye table and the artificial eye tablet should not exceed 5g. Wearing heavy artificial eyes for a long time may lead to adverse consequences such as ectropion and relaxation of eyelids. In addition, for patients with custom-made glass artificial eyes, the most headache is the fragility of glass artificial eyes and the cost of post-maintenance Glass artificial eye belongs to one-step artificial eye piece, which cannot be modified again after customization. After the patient customized the artificial eye piece, the eye cavity muscles will change due to gravity or postoperative swelling, but the glass artificial eye can not be adjusted in time according to the changes of eye tissue. This can be said to be the biggest "hard injury" of glass artificial eye.
Resin artificial eye
Resin artificial eye is essentially a plastic artificial eye (organic), that is, synthetic resin. The raw materials of both are the same. Resin eye prosthesis has low cost, a piece of resin eye prosthesis costs a few dollars at most, and its service life is short, which belongs to the eye prosthesis products that have been eliminated for a long time. Many unqualified "black-hearted" custom-made institutions usually use resin artificial eyes as imported polymer artificial eyes and then offer high prices to deceive patients, which directly leads patients to enter the trap set by merchants without knowing the truth. Until the money was finally spent, the artificial eye tablets exploded, yellowed and faded after a few months of use. Therefore, when choosing an artificial eye customization organization to customize the artificial eye, please first understand the qualification and customization strength of the artificial eye customization organization, and don't be used by black-hearted merchants.