Eyes are indispensable organs for people's work, life and study, and 80% of people's information and more than 95% of their work can only be completed by eyes. Without eyes, the world is dark. Eyes are delicate and delicate tissues, and people often describe them as "eyes can't get into sand". Therefore, the eyes have become the key protection objects and people's "second life". Because of the important position of eyes, the emergence of any new technology can first attract the attention of ophthalmologists. So it is not surprising that the first medical field of laser application appeared in ophthalmology.

Laser "wrench" for correcting eyesight

I don't know why, at present, more and more people suffer from myopia. Some of these patients feel that wearing glasses is unsightly or affects some sports work, and the contact lenses that are popular now are not only too bulky, but also risk causing new inflammation.

Since people's eyes can adjust the focal length of an image like a camera, why can't they adjust it by rotating the thread like a camera lens? Theoretically, it was conceived a long time ago, but it lacked a "wrench" to adjust the "line"-a precise ophthalmic surgical instrument.

With the development of laser technology, this idea has been put forward again, and it has been successful in animal experiments and clinical practice. This means that the end of the 20th century can provide us with a vision correction technology that can replace glasses.

1983, researchers from Columbia University proved that corneal tissue can be gradually removed by directly breaking molecular bonds. 1988 Watson research center of international business machine company proved for the first time that excimer laser keratectomy is very accurate, which can reach nanometer level and has little damage to surrounding tissues. This is because excimer laser "cuts" cold by breaking the chemical bond between two molecules. Animal experiments show that with the cooperation of microscopic technology, this technology can even correct the refractive value of eyes according to the degree, which is simply wonderful.

In order to control the position and depth of excimer laser keratectomy more accurately, Professor Kenchun Tufei of Tokyo University and Professor Dorothy and Dorothy of Medical College introduced excimer laser keratectomy with laser scanning system. It is characterized by scanning the corneal surface with He-Ne laser, measuring its shape, and then excising it with excimer laser, thus improving the accuracy and safety of corneal surgery.

Prior to this,1September, 988, the former Soviet Union had developed a fully automatic laser eye treatment machine, which used thermal evaporation to perform PRK surgery. This kind of operation was performed in 80 cases in the former Soviet Union and 10 cases in Germany, all of which were said to be successful.

Good news for glaucoma patients

Glaucoma is a disease that middle-aged people are prone to, and its clinical symptom is increased eyeball pressure. If not treated in time, it will often lead to blindness. The traditional treatment is surgical incision and decompression.

The US Food and Drug Administration has approved two technologies to treat glaucoma with laser.

One is holmium laser from Sunray Technology Company to treat glaucoma. During the operation, the doctor inserted the needle into the conjunctival cortex and used the timely optical fiber to transmit the holmium laser to the sclera. By controlling, the emitted laser is at right angles to the fiber direction, and a small hole with a diameter of 0.2 ~ 0.3 mm is burned on the sclera. Let the drug flow into the cavity between conjunctiva and sclera to maintain proper intraocular pressure. The output wavelength of this holmium laser is 2. 10 micron, and the energy of each pulse is 0. 1 joule.

Lashag Company in Annapolis uses Nd: YAG laser to thermoform small cylinders. This is an operation to reduce the intraocular pressure of patients with unconstrained glaucoma. It is said that the laser produced by this company is the only Nd-doped YAG pulse laser device available to ophthalmologists.

Light "needle" skillfully dials cataract

Cataract is also a common eye disease of human beings, which is characterized by producing a glassy or colloidal, translucent and opaque object in the lens of human eyes, which directly hinders the passage of light.

Before 1980, the only way to treat cataract abroad was to open the posterior capsule by surgery, which required general anesthesia. In China, the "needle extraction" operation is adopted, which is a kind of operation to push the cataract capsule under the vitreous body and enjoys a high reputation internationally. Later, researchers from Paris University and Berne University in Sweden found that laser-induced shock waves were extremely useful for removing secondary cataracts.

They used a Nd-doped yttrium aluminum garnet laser with the wavelength of 1.06 micron to emit nanosecond or picosecond pulses, and focused the infrared laser on or near the opaque back film, thus tearing it with the shock wave generated by the laser.

After laser treatment, the patient's vision improved almost immediately. In the United States, more than 200,000 operations called posterior capsulotomy are performed every year. Unlike the traditional surgery that cost $2,000 in the early stage, the cost of laser surgery does not exceed $65,438+0,000, and there is no need for general anesthesia or hospitalization.