There are three 100% of clinical trial results of Mih artificial cornea.
100% literacy rate in 12 months
At 12 months, 23 cases were 100% better than those before operatio
12 month incumbency rate reaches 100%
Words such as "getting rid of blindness" and "getting better than before surgery" must be easy for everyone to understand. However, when it comes to the incumbency rate, some people begin to be confused, and have some incorrect guesses that affect their judgment.
So, let's share with you today what is the so-called "incumbency rate" of artificial cornea? Why can the anatomical presence rate of Mihm artificial cornea reach 100%?
The incumbency rate, as the name implies, is the ratio of incumbents to the total number of people. In the operation of artificial cornea, the replacement of artificial cornea (due to tissue dissolution, water leakage, displacement and fall off of artificial cornea, etc.) can be called anatomical failure. Therefore, the "presence rate" of artificial cornea can be said to be "the ratio of the artificial cornea that has not been replaced to the operative eye." 100% "presence rate" means that no product has been replaced.
The ideal effect of artificial cornea surgery is to enable patients to obtain good visual function and anatomical presence rate, and effectively reduce complications. However, at present, few artificial corneas can guarantee 100% of the presence rate during surgery.
Take two examples:
Boston artificial cornea needs corneal grafts as carriers, which may lead to aseptic dissolution of the later grafts. In severe cases, it may lead to corneal prolapse, infection, and even blindness again. Especially for patients with autoimmune diseases, the failure rate of surgery is higher.
Therefore, Boston keratoprosthesis has a high tissue dissolution rate. Although the product was improved in the later stage and patients wore soft contact lenses to prevent corneal dissolution, it still did not help patients with poor ocular surface conditions.
OOKP uses autologous teeth and surrounding tissues as artificial cornea scaffold, which has good biocompatibility and high surgical success rate. However, its presence rate can not be guaranteed, mainly due to the tooth plate absorption.
Absorption will cause the tooth plate to become thin or defective. When absorption affects the central hole of the tooth plate, the lens column will become loose and unstable, which will eventually lead to aqueous humor leakage, diopter change, optical axis change caused by plate tilt, and even cause endophthalmitis, leading to vision loss.
As for why the artificial cornea is so easy to appear tissue dissolution and prolapse, there are reasons to follow.
The surface tissue of artificial cornea needs good vascularization, which is easy to cause tissue dissolution when the local tissue lacks the vascular membrane of fibrous connective tissue covering the artificial cornea.
In addition, the local tissue of patients with artificial cornea has become very thin and fragile before surgery. In addition, lamellar separation is required during surgery, which greatly increases the risk of tissue dissolution, aqueous humor leakage and artificial cornea prolapse. The early operation of Mihm artificial cornea is no exception. It is gratifying that after many years of clinical trials, we have summarized the methods to prevent the above phenomena.
For example, the autologous conjunctiva or lip mucosa is covered at the same time as the Phase I keratoprosthesis is implanted to promote the vascularization of ocular surface tissue as soon as possible. Seeing this, some people may wonder whether the increase of blood vessels will lead to rejection? Why promote vascularization?
In fact, at present, many researchers believe that, unlike corneal transplantation, good vascularized corneal conditions are required for the clinical application of artificial corneal stent.
The neovascularized corneal graft bed can provide a good microenvironment for cell proliferation and migration, promote cell proliferation and collagen synthesis, reduce corneal dissolution after surgery and the excretion rate of artificial cornea, which is conducive to the stability of artificial cornea.
Of course, only covering with conjunctival flap can not prevent artificial cornea from prolapse. Therefore, in order to further increase the stability of the artificial cornea, ear cartilage will be reinforced for those with thinner ocular surface tissue in the later stage: the area and shape of cartilage will be trimmed according to individual conditions, and it will be reinforced in front of the two loops of the scaffold.
Ear cartilage is often used for nose plastic surgery and tarsal plate replacement surgery. As living tissue of its own, active chondrocytes have been effectively preserved, with a high survival rate, good biocompatibility and stability, good elasticity, moderate hardness, easy shaping, no rejection, and no complications such as displacement of the lens column caused by bone absorption.
In a word, Mihe keratoprosthesis can promote the vascularization of the ocular surface as soon as possible by covering the conjunctiva or labial mucosa to maintain the nutrient supply of the anterior lamellar tissue, thus reducing the possibility of tissue dissolution. Combining with ear cartilage reinforcement is an important measure to prevent aqueous humor leakage and keratoprosthesis prolapse.