Corneal transplantation is a relatively successful tissue transplantation operation in human history, with a success rate of 95%. However, with the extensive development of corneal transplantation, more corneal grafts are still turbid after surgery, and irreversible graft edema will lead to graft failure.
Among them, the most troublesome problem for doctors and the most worrying problem for patients is the aseptic ulcer, dissolution and even perforation of the graft after surgery.
In fact, no matter penetrating keratoplasty, lamellar keratoplasty, therapeutic or optical keratoplasty, or artificial cornea, postoperative graft fusion may occur.
For example, Boston I artificial cornea requires corneal grafts as carriers. Later, the grafts may be sterile dissolved, which may lead to device prolapse, infection, and vision loss in severe cases. Especially in patients with autoimmune diseases, the rate of anatomical failure is higher.
So, what are the risk factors that cause the graft to melt after corneal transplantation? Friends in need can refer to it.
The first is the high-risk planting bed. The incidence of graft rejection was 40%~65%. High risk implant beds are prone to acute rejection due to the formation of a large number of new blood vessels (commonly known as corneal neovascularization), leading to graft matrix necrosis, dissolution, and even perforation.
The second is the presence of dry eyes before surgery. In dry eye patients, due to the lack of tear, instability of tear film or absence of tear film, there will also be a large number of corneal neovascularization. If these patients have undergone corneal transplantation, graft necrosis and dissolution are easy to occur after surgery. Common diseases such as ocular surface chemical or thermal burns, Stevens-Johnson syndrome, etc.
The third is rheumatism related diseases. There are many kinds of rheumatism related diseases, including rheumatoid diseases, such as rheumatoid arthritis and Reiter syndrome, which can cause eye lesions; Vascular diseases such as Wegener's granuloma, nodular arteritis, erythema multiforme, etc; Connective tissue diseases such as recurrent polychondritis, systemic lupus erythematosus, etc.
About 70% of these patients have lacrimal gland secretion dysfunction, and some patients may have spontaneous keratolysis, iritis, necrotizing scleritis, etc. Such patients are also prone to graft necrosis and dissolution, even graft bed dissolution, if corneal transplantation is performed.
The fourth is graft versus host disease: systemic large organ transplantation may cause rejection, leading to systemic graft versus host disease. Bone marrow transplantation is more common in ocular reactions.
Rejection occurs after bone marrow transplantation. The common manifestations of the affected eyes are dry eyes, corneal epithelial defects, ulcers, corneal necrosis, melting and even perforation, uveitis, etc.
The fifth is trigeminal paralysis: that is, the cornea lacks sensory innervation. Such corneas may have epithelial shedding, matrix melting, or even perforation.
Many diseases of the eye and other systems can cause corneal sensory disorders, the most common being herpes simplex virus infection and herpes zoster virus infection of the eye.
The sixth is eyelid insufficiency: trigeminal nerve palsy, eyelid trauma, congenital eyelid defect, hyperthyroidism and other ocular and systemic diseases can cause eyelid insufficiency, and the cornea can lose the protection of the eyelid and be exposed to the air, which can cause corneal epithelium dryness, fall off, ulceration and even dissolution.
Epithelial defects, ulcers, and even matrix necrosis and melting of the grafts are easy to occur in patients with eyelid insufficiency after corneal transplantation.
So, once the corneal graft melts, how should it be treated?
The causes of graft fusion after corneal transplantation are different, and drugs or surgery can be selected according to different conditions. For example, immunosuppressive agents (glucocorticoid should be used with caution when the graft is dissolved, because it can also activate collagen plasminogen to become lysase in addition to immunosuppressive effects, and accelerate the graft dissolution), heparin (can slow the graft dissolution), collagenase inhibitors (can reduce or inhibit the graft dissolution), or antibiotics (conducive to the healing of the dissolution).
After the graft fusion, if the conservative treatment fails, the patients with graft fusion progress and perforation tendency or perforation need to undergo corneal transplantation again. Lamellar or penetrating keratoplasty can be selected according to the scope and depth of the lesion, and artificial keratoplasty can be used when necessary.
Mih artificial cornea is composed of lens column and stent. It is applicable to patients with binocular corneal blindness who are difficult to succeed in corneal transplantation, including corneal transplantation failure, severe keratoconjunctival scar vascularization caused by chemical injury, thermal burn, explosive injury, eyelid atresia, severe autoimmune diseases (such as Stevens Johnson syndrome and cicatricial pemphigoid), corneal blindness caused by terminal dry eye, etc, The appearance of Mihm artificial cornea provides a new way for the clinical treatment of patients with contraindication of traditional corneal transplantation.
Moreover, the product is made of artificial materials without donor cornea, which not only alleviates the shortage of corneal donors in China, but also avoids rejection reaction. It can be said that after the implantation of Mih artificial cornea, there is no need to perform a second operation.
The operation mode of split design and staged implantation enables the product to anchor with the surrounding corneal tissue; The artificial cornea column is fixed on the patient's eye by screwing in the bracket with a threaded structure. The risk of injury to the affected eye is greatly reduced during the implantation operation, which improves the product's occupancy rate. If you or your relatives and friends in front of the screen need help, you can call the Bright Hotline of Mihm Medical: 400-111-8801.