The wearing of orthokeratology lenses to protect teenagers' eye health must be standardized first.

Ophthalmologists in Shougang Hospital of Peking University provide orthokeratology glasses for myopia children. Information picture

At the beginning of April, the Ophthalmology Branch of Chinese Medical Association issued a new edition of "Instructions for Experts on the Fitting Process of Orthokeratology Lens", which made detailed provisions on the indications and contraindications of Orthokeratology Lens, the standard test and fitting process, and the precautions for standardized inspection during fitting, ensuring standardization and safety.

According to the relevant regulations of the state, orthokeratology must be fitted in the second-class and above medical institutions with the Practice License of Medical Institutions, and it is required that the fitting doctors of medical institutions should have the qualifications of ophthalmologists at or above the intermediate level, and the fitting technicians should have the titles of technicians at or above the intermediate level, and the fitting work must be completed with the cooperation of ophthalmologists.

Orthokeratology has developed for four generations.

Orthokeratology glasses are mainly worn when sleeping at night, usually 8 to 10 hours. If the wearer uses unconventional correction, if there is residual degree, he may need to wear a pair of low myopia glasses during the day.

Orthokeratology mirror was born in the United States in the 1960s, but it was not widely used in clinic due to the limitations of lens materials, design and fitting. In 1990s, with the appearance of orthokeratology mirror with four zones and five arcs "reverse geometry" design, as well as the development of corneal topographic map technology and the update of production materials, the safety, accuracy and effectiveness of orthokeratology mirror were greatly improved, and it was gradually applied and popularized in clinic.

From 1998 to 200 1, the number of orthokeratology mirrors in China has increased rapidly. After 2002, 13 cases of orthokeratology lens wearers developed severe corneal infection and ulcer, which caused irreversible damage to the cornea due to untimely treatment, and the use of orthokeratology lens once reached a low point.

In recent years, with the improvement of China's relevant management system, the continuous maturity and popularization of medical fitting technology, and the improvement of wearer's education and compliance, more and more people with moderate and low myopia choose to wear orthokeratology lenses, which has become one of the main means to prevent and control myopia in children and adolescents.

According to Wenda, so far, orthokeratology has gone through four generations of design and has been applied in 34 countries around the world. Because of the different materials, oxygen permeability, manufacturing technology and design methods of orthokeratology lenses, the use effect and safety are different, and the market price is also very different. Orthokeratology lens is divided into domestic and imported products. The price of each domestic product ranges from 5,000 yuan to 8,000 yuan, and the price of each imported product ranges from 1 10,000 yuan to1.4,000 yuan.

According to the statistics of optometry branch of China Medical Device Industry Association, in 20 18 years, the number of orthokeratology lenses used in China was 640,000, and the industry penetration rate was only about 1%. It is estimated that by 2023, the market penetration rate of orthokeratology lenses in China is expected to reach about 2%, the compound annual growth rate will reach 30%, and the market scale is expected to reach 23.7 billion yuan.

At present, nine orthokeratology mirror enterprises in China have obtained product registration certificates issued by the national drug regulatory authorities.

Orthokeratology mirror taboo.

The corneal epithelium of the patient's right eye was scratched due to the adverse reaction during use. Information picture

Zhang Xiaotong, a junior two student, started wearing orthokeratology glasses three years ago. At the beginning of May this year, his eyes showed redness, pain, difficulty in opening eyes, tears and other symptoms, and he immediately went to the hospital for ophthalmology treatment. By using slit lamp microscope, he found many scratches on his left cornea.

Upon inquiry, the attending doctor learned that at the turn of spring and summer, the child had allergic symptoms such as itchy eyes, stuffy nose and sneezing, but did not stop using orthokeratology according to the doctor's advice. After wearing glasses at night, my eyes itch a little, so I rubbed my eyes hard with my hands, causing corneal epithelial damage without involving the deep cornea.

"In clinical treatment, cases of adverse reactions in myopia patients during the use of orthokeratology lenses have occurred from time to time, and some even have serious consequences." According to Wenda, the outermost corneal epithelial cells in the corneal structure can be regenerated. After repairing the cornea and using eye drops to prevent infection, the child's corneal injury was completely cured after one week, leaving no sequelae.

Corneal infection is a complication of wearing orthokeratology lenses, mainly due to unqualified hand hygiene, washing lenses with dirty water containing pathogenic bacteria, and poor cleaning of lens boxes, but it can be prevented and controlled.

At the same time, when the body's resistance is low, try not to wear orthokeratology glasses, including fever, cold, skin allergy, viral infection, acute eye disease and other diseases, which can also lead to corneal infection.

Li Gang reminded everyone that the cleaning and nursing of orthokeratology mirror is very important. Every day, use professional nursing liquid to soak and clean the lenses, the mirror box and the suction stick. We should use AB disinfectant or hydrogen peroxide to remove protein from the lens every week, and never use tap water to clean the lens.

"Orthokeratology mirror adopts high oxygen permeability material, which has good wettability, air permeability and light transmittance and high safety. However, some adverse reactions will inevitably occur during wearing and should be stopped in time. " Li Gang said that if the doctor's design scheme and myopia patients use it improperly, or wear products that do not meet the national standards, it will easily lead to corneal inflammation, perforation, dry eye, thinning of corneal center, keratoconus, and even blindness in both eyes.

Please stop wearing the lens when there are many protein deposits, scratches, serious wear and tear, or the edge of the lens is cracked. If you continue to wear it, it will affect eye health and may also cause corneal scratches.

Li Gang said that at present, orthokeratology mirror manufacturers suggest that the lens replacement cycle is one year. In China, users of orthokeratology lenses usually wear 1 to 1.5 years, and long-term users have to pay for lens damage, replacement, consumption of care products, follow-up visits, etc. Wearing the lens for more than one year is easy to scratch and deform the lens, which affects the control effect of vision and myopia. Wearing orthokeratology lens for a long time is more likely to affect corneal health.

At the same time, with the increase of age, the shape of cornea will also change, which may lead to improper wearing of orthokeratology, thus affecting the effect of orthokeratology. After some children and adolescents wear orthokeratology lenses, their myopia will continue to deepen. Therefore, when the tear quality or eye parameters of the wearer change during the development, it is necessary to replace the lens in time according to the advice of the optometrist.

Wearing orthokeratology glasses can't cure myopia.

Some people say that wearing orthokeratology can cure or cure myopia. In this regard, Li Gang made it clear that a large number of medical studies show that under the current medical technology conditions, myopia is irreversible, and wearing orthokeratology glasses cannot cure myopia, let alone cure myopia.

"Myopia is a continuous eye disease, and the progress of myopia in children and adolescents wearing orthokeratology lenses will generally slow down." Li Gang emphasized that orthokeratology is a non-surgical myopia correction method. Wearing orthokeratology glasses can not completely stop the development of myopia, but delay the development of myopia and improve naked eye vision quickly during the treatment.

"The therapeutic effect of orthokeratology is reversible," Li Gang said. Because the mechanical pressure of orthokeratology lens is limited, the curvature of cornea will gradually recover from morning till night. If the orthokeratology treatment is stopped for some reason, the effect of orthokeratology will disappear, and myopia and corneal morphology will return to the state before wearing after a certain period of time.

Wen Da introduced that the growth of myopia is mainly due to overuse of eyes, and orthokeratology has only an auxiliary therapeutic effect on myopia. If the wearer still overuses his eyes, myopia will still develop rapidly.