The principle of myopic laser surgery is to use a laser to make the cornea thinner so as to achieve a corrective effect. There are three main principles of this operation:safety, effectiveness and stability.
Absolute contraindications in laser surgery include:
1. conical cornea, corneal dilatation; 2. autoimmune diseases, this group of people are prone to corneal lysis, so corneal ablation is not recommended. 3. systemic diseases or some metabolic diseases, for example, severe hyperthyroidism or hyperthyroid synostosis; corneal exposure in this group is severe and predisposes to an increased likelihood of keratolysis with surgery. 4. Active eye disease, such as intraocular infection and corneal infection. Surgery is contraindicated during infection or inflammation. 5. Patients with cataract or glaucoma who have poor fundus function or whose vision is severely affected.
Relative contraindications in laser surgery include:
1. Under the age of 18, if you are too young to have surgery, you are likely to improve your degree.
2. Diabetic patients, glucose control is unstable, resulting in metabolic disorders of the nerve endings system. The cornea is a nervous tissue with no blood vessels. It is dependent on nerve sources for nutrition. If the cornea is cut with a laser, the recoverability of the cornea will be very poor, affecting the corrective effect.
3. People with a history of eye surgery, those who have undergone more complex fundus surgery or those with poor fundus function. In addition, severe retinal detachment, very large or irregular corneal leukomalacia, and ocular accessory injuries (e.g., eyelid defects that may interfere with corneal nerve recovery). However, corneal transplant patients can still undergo surgery if they develop astigmatism or myopia.
4. Keloid scarring, people with this type of body type not only have slow healing wounds, but also slow nerves. Therefore, after cutting the cornea, the cornea is more likely to form irregularities or scar healing, which will affect vision and visual quality. The recovery period for laser surgery varies from person to person and can be within a day or two.