According to the World Health Organization's global data report on visual disability, there are more than 8 million blind people in China. Corneal disease is the second major blindness after cataract. At present, there are about 4 million patients in China, increasing at the rate of 100000 per year, including 10% of patients with severe corneal blindness.
Among them, due to poor working conditions and differences in regional medical conditions, the proportion of patients with chemical injury and thermal burn for various reasons is high, and many corneal diseases can not be treated reasonably and eventually lead to blindness.
On the other hand, the rate of corneal donation in China is very low, with less than 10000 corneal transplants per year. Therefore, according to the current situation of our country, relying solely on corneal transplantation can not restore the vision of these corneal blind patients. It is more urgent to develop corneal substitutes.
In order to solve this problem, in recent years, the research direction in this field has mainly focused on corneal stem cell transplantation, tissue-engineered cornea, amniotic membrane transplantation and other fields. Unfortunately, despite the above various corneal replacement methods, most of them are in the early stage of clinical or even basic research stage, and the adaptability is narrow. For high-risk or repeated corneal transplantation failure cases of corneal transplantation, such as severe vascularization or scar of cornea caused by chemical or thermal burns, The success rate of corneal transplantation in patients with Stevens Johnson syndrome, cicatricial pemphigoid and severe dry eye is very low.
The research and development of artificial cornea technology provides a new idea and method to help this kind of corneal blindness.
Artificial cornea is an artificial device that can replace the cornea to exert optical properties. At present, Boston artificial cornea is widely used all over the world. Although it continues to innovate in design and materials, and the corresponding complications are greatly reduced, the anatomical failure rate of patients with severe ocular surface damage and autoimmune diseases is still high, and allogeneic cornea is additionally needed as carrier. Combined with the shortage of corneal materials in China, the clinical promotion is limited to a certain extent.
Moreover, it has to be said that this design is likely to lead to aseptic dissolution of later implants, and in serious cases, it will lead to device prolapse, infection and loss of vision. Especially in patients with autoimmune diseases, the rate of anatomical failure is higher. Therefore, for some patients with poor ocular surface conditions, Boston artificial cornea is not only a "good person", but also a "enemy".
The ophthalmology department of the PLA General Hospital reviewed the case data of patients with artificial cornea and found that compared with developed countries, the overall condition of patients with artificial cornea in China is more complex and serious: there are many high-risk cases, especially chemical injury, thermal burn and infection. Their ocular surface condition is so poor that it is difficult to carry out either routine corneal transplantation or Boston artificial cornea.
For them, Microk is the only and last hope.
Unlike Boston artificial cornea, Microk is not only made of artificial materials without donor cornea, but also has a wide range of indications. It is suitable for patients with bilateral corneal blindness who are difficult to succeed in corneal transplantation, including severe keratoconjunctival scar vascularization and eyelid atresia caused by corneal transplantation failure, chemical injury, thermal burn, explosion injury, etc, Severe autoimmune diseases (such as Stevens Johnson syndrome and cicatricial pemphigoid), corneal blindness caused by end-stage dry eye, etc.
This means that China has become one of the few countries in the world with its own property rights of artificial cornea products. Previously, corneal blindness patients who were considered by clinicians as "terminally ill" have a chance to see light again.
Since quengsy put forward the concept of replacing turbid cornea with artificial cornea in 1789, many successful related studies have been reported. However, there are some potentially serious complications in the products. The staged surgical implantation of Microk can avoid serious intraoperative complications of other artificial corneas, such as expulsion bleeding and water leakage, to the greatest extent through intraocular perfusion and small corneal opening.
In addition, PMMA is a medical scaffold material with low elasticity, excellent mechanical properties and processability. The central optical part of the utility model is connected with the titanium bracket through threads, and the processing accuracy is extremely high. The watertight combination between the mirror column screwed in place and the bracket can prevent low intraocular pressure caused by water leakage and reduce the chance of intraocular infection.
In a word, Microk has created conditions and provided a reliable method for the rehabilitation of severe corneal blindness in China. At the same time, we also believe that with the continuous R & D and improvement of artificial cornea and the application of various new polymers and biomaterials, the indications of artificial cornea will be more extensive, the implantation process will be more convenient and the long-term effect will be more stable in the future.