2021-03-03

1 hour surgery, reading the newspaper the next day: cornea, artificial

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1 hour surgery, reading the newspaper the next day: cornea, artificial

It is reported that the artificial cornea used in this operation is called CorNeat, which is made of non-degradable porous material and is the first direct implant in history. Implants in the eye wall without donor tissue can replace the damaged cornea that causes severe vision loss.

1 hour surgery, reading the newspaper the next day: cornea, artificial(1)

“It is based on material selection and technical design They are all very advanced. Judging from the current clinical data, the patient’s postoperative results are also very good, but it still needs a long period of observation to finally determine the effect.” Huang Ting, chief physician of the Department of Corneal Diseases, Zhongshan Eye Center, Sun Yat-sen University told “China Science News.”

The cornea is commonly known as the “black eyeball”, located directly in front of the eyeball. “It’s like a camera lens. It can ensure that outside light can pass through without obstacles, pass through the pupils, reach the fundus, and finally get a clear image.”

Zhao Jialiang, chief physician of the Department of Ophthalmology, Peking Union Medical College Hospital, is receiving “China In an interview with Science Daily, the cornea is always the first to bear the brunt of trauma. It is vulnerable to different degrees of injury and rupture; or infection, resulting in turbidity, loss of vision or blindness.

From 2009 to 2012, under the funding of the key consulting research project of the Chinese Academy of Engineering, “Research on the Social Hazards and Intervention Strategies of Infectious Corneal Disease in China”, Xie Lixin, an academician of the Chinese Academy of Engineering, organized 10 provinces, autonomous regions and municipalities ( A total of 191,242 people were sampled. The results of the epidemiological survey of infectious corneal disease showed that the prevalence of corneal disease in China was 2.49%. Based on the estimated population of 1.3 billion people in the sixth national census, there were 32.37 million people with corneal disease in China. Among them, the number of patients with corneal blindness is about 3.3 million, and it is increasing at a rate of 100,000 to 150,000 per year.

Zhang Yongwei, a lecturer at Tokyo Medical and Dental University in Japan, told China Science Daily that the main cause of corneal blindness is infection and trauma, which mostly occur in areas with poor sanitation and people with relatively low incomes. For example, remote rural areas in China, Southeast Asia, Africa and many other regions are areas with high incidence of corneal blindness.

At present, the only effective treatment for corneal blindness caused by corneal diseases is corneal transplantation. Zhao Jialiang said that 80% of people can see the light through corneal transplantation.

However, due to the lack of donor corneas, there are only less than 8,000 corneal transplant operations in China each year, compared to 45,000 in the United States.

Pan Zhiqiang, chief physician of the Department of Cornea, Beijing Tongren Hospital, previously stated that the number of patients registered for corneal transplantation in the hospital each year is about 1,000, but only more than 100 patients can get donated corneas, and the rest of the patients Surgery depends on domestic and foreign eye banks to support or adjust the cornea.

Just the first step in multinational clinical trials

In order to solve the problem of donor cornea deficiency, scientists have turned their attention to the research and development of tissue engineering cornea (bioengineered cornea) and artificial cornea.

Among them, decellularized porcine cornea is a typical representative of tissue engineering cornea, which is made from porcine corneal stroma after decellularization and other treatments to solve the problem of insufficient donors. The decellularized cornea can be well integrated with human tissues to achieve tissue integration. In appearance, it is impossible to distinguish which is the transplanted cornea and which is the original cornea.

“However, it is only used for partial lamellar corneal transplantation and cannot be used for the treatment of full-thickness corneal opacity.” Huang Ting said that at present, China has completed the registration of medical devices for “Udeqing” and “Aixin”. Pupils are all bioengineered cornea.

In the United States, two kinds of artificial cornea, Boston artificial cornea and AlphaCor artificial cornea, have been approved by the National Food and Drug Administration and used in clinical practice.

Zhang Yongwei said that these two artificial corneas have a traditional artificial corneal skeleton structure-composed of a core part for light transmission and a group part for fixation. They usually fail or are considered to be failed after repeated corneal transplantation. Corneal transplantation is used in high-risk situations.

And this time, the CorNeat artificial cornea developed by Israeli scientists uses electrospinning technology to use nanofibers to simulate the extracellular matrix structure to make a skirt part, which has a high biocompatibility. Not only is it conducive to the entry and implantation of the recipient cells, but also the fixation with the sclera is used to increase the fixation force of the artificial cornea.

“CorNeat artificial cornea operation is simple, the whole process takes less than one hour, and the patient can read the next day, which is really a pleasant surprise.” Zhang Yongwei said, compared with Boston artificial cornea and AlphaCor artificial cornea , CorNeat artificial cornea has made great progress in aesthetics.

It is understood that the specific procedure of CorNeat artificial cornea is to separate the conjunctiva from the sclera to form a pocket; then remove the patient’s cornea, and insert filaments along the edge of the eye and sclera; with the help of sutures KPro is implanted, and then the conjunctiva is sutured back to the sclera.

“This is just the first step in a multinational clinical trial.” Almog Aley-Raz, co-founder of CorNeat Vision, the artificial cornea design company, pointed out in a statement.

Zhang Yongwei also pointed out that the electrospinning technology used in CorNeat artificial cornea is not a completely new technology. “So although the materials used for the optical part of the core are not clearly disclosed, we believe that this is not so much a brand-new technology, but rather an advancement or a new combination (technology/material) that is more appropriate.”

< p>However, Huang Ting pointed out that all artificial corneas have a problem, that is, there may be long-term leakage of the artificial cornea and the patient’s cornea, or even corneal detachment.

“Although CorNeat artificial cornea can be used for full-thickness transplantation and uses highly biocompatible materials, it still takes time to observe the long-term effect.” Huang Ting said.

Zhang Yongwei also said that due to the influence of material and structural factors, the general artificial cornea cannot correctly detect intraocular pressure, which may easily cause glaucoma or aggravate primary glaucoma. “Whether the CorNeat artificial cornea solves this problem is To be verified”.

Speaking of artificial cornea research in the future, Huang Ting suggested that some artificial materials that are highly compatible or the same as human tissues should be studied to solve the problem of tissue healing after surgery and avoid leakage of wounds and artificial corneal prolapse.

“We should also develop new technologies to make a cornea that can ensure long-term stable and safe use, so that the artificial cornea can be used for life. In addition, combining electronic communication technology to prepare a multifunctional artificial cornea is also a research hotspot .” Zhang Yongwei said.