Artificial cornea is a special refractive device made of heterogeneous materials to replace turbid corneal tissue. It can be implanted into the affected eye to obtain a certain vision.
It should be noted that each artificial cornea has a different product design, resulting in different postoperative medication and care methods. In particular, there are significant differences in medication and nursing care for the collar button keratoprosthesis and Mihm keratoprosthesis. So, what's the difference between the two prognosis? Let's have a look.
On the whole, there are two differences in postoperative medication and postoperative care.
Medication
○ Long term local application of anti rejection eye drops is required after collar button keratoplasty
○ After Mihm artificial cornea transplantation, only artificial tears need to be given for a long time (4-6 times a day, which can be reduced according to the ocular surface), To maintain eye surface stability
○ Long term topical application of glucocorticoid eye drops is required after button type keratoplasty
○ Glucocorticoid eye drops can not be used locally after Mihe keratoplasty
nursing
△ After the button type artificial cornea transplantation, the patient needs to continue to wear a large diameter corneal bandage lens and wear protective glasses.
△ After Mihm keratoprosthesis transplantation, patients only need to wear protective glasses.
Obviously, they are all artificial corneas. Why is the prognosis so different? Next, let's analyze them one by one.
First of all, why is it necessary to apply anti rejection eye drops locally for a long time after the button type artificial cornea transplantation? The root cause was that the donor cornea was implanted during the operation.
As we all know, the corneal encounter of allografts is likely to lead to a "war", that is, mutual exclusion. In addition, for patients with multiple corneal transplant failures and poor ocular surface conditions such as autoimmune diseases, the possibility of rejection is higher, so anti rejection drugs must be used.
However, Mihe artificial cornea is made of artificial materials, and does not need donor cornea, so we do not need to worry about rejection. We only need to give artificial tears to improve the stability of the ocular surface.
Secondly, glucocorticoid should be used after the button type keratoprosthesis. The Chinese Expert Consensus on Artificial Corneal Transplantation (2021) clearly states that tobramycin and dexamethasone eye drops are applied locally 4 times a day; Tobramycin and dexamethasone eye ointment, once a night. 2 weeks after operation, 1% prednisolone acetate eye drops were changed, 4 times a day, and the dosage was reduced once a week; Tobramycin and dexamethasone eye ointment was changed to once every other night. One month after operation, 0.1% fluminolone eye drops were changed to 4 times a day, gradually reduced, and maintained once a day or once every other day according to the eye conditions; Tobramycin and dexamethasone eye ointment was changed to twice a week. Glucocorticoid eye drops may not be used locally after Mich artificial cornea transplantation.
In addition, the button type artificial cornea also needs to be changed to oral doxycycline 3 days after intravenous infusion of broad-spectrum antibiotics according to the patient's condition and surgical conditions. The dosage is 100 mg/time, once a day. It is recommended to use it for 3-6 months, and check the liver function every 3 months.
Doxycycline has a broad antibacterial spectrum. It is used for infections caused by bacteria, rickettsia, mycoplasma and chlamydia, and can prevent the infection of falciparum malaria and leptospira.
The reason why the button type artificial cornea is changed to oral administration of this drug after surgery is that the button type artificial cornea uses the donor cornea during the implantation process. In order to inhibit the donor cornea fusion, oral doxycycline is required. As mentioned above, Mihm artificial cornea is made of pure artificial materials, and there is no need to worry about this problem.
Next, we will talk about why the patients need to wear large diameter corneal bandage lens continuously after the button type artificial keratoplasty.
The Clinical Application of Boston Type Artificial Cornea mentioned that patients need to wear soft lenses after surgery to prevent the evaporation of eye water and reduce the depression of artificial cornea, thus reducing the possibility of donor corneal necrosis and dissolution. In short, it is because the donor corneal graft was implanted during the operation.
There is a close mosaic relationship between the collar button type artificial cornea and the carrier, which is not completely the same as the classical penetrating keratoplasty healing mechanism. Therefore, lifelong medication and care after surgery are particularly emphasized, such as wearing contact lenses, collision prevention, trauma prevention, etc. Of course, care should also be paid to Mihm after keratoprosthesis transplantation, but the way is simple and convenient, and there is no need to worry too much.
Here we need to remind you that it is very important to take the medicine for a long time according to the doctor's advice. We must master the correct method of ophthalmic drugs and the method of drug preservation. The opening of the medicine bottle should not touch anything, including the eyes, so as to prevent the eye drops from being polluted and causing injury or infection to the operation eyes. After discharge, visual aids can be used to improve their visual activity ability, such as mobile phones for the elderly, large print, lighting reading brackets, home decoration and color contrast.
Finally, in addition to routine nursing care, patients and their families should focus on the observation and nursing of postoperative complications. Patients and their families should realize the importance of adhering to the lifelong local application of antibiotic eye drops, collision prevention, trauma prevention, and return to the doctor's advice for relevant imaging examinations, so that secondary glaucoma, inflammatory reaction, the formation of anterior and posterior membranes of artificial cornea and other complications can be detected and treated early, Prolong the service life of artificial cornea.