——"Myopia Prevention and Control, Health Education" Series of Popular Science (3)
Ren Yanru, Department of Ophthalmology, Characteristic Medical Center (formerly 306 Hospital).
Edited by Liu Yan/Cui Yan, Medical Science Popularization Center
In recent years, the prevalence of myopia in children and adolescents in mainland China has been rising, and myopia and high myopia in children have gradually become public health problems affecting national health. Orthokeratology lenses (OK lenses) are special rigid contact lenses that can be worn at night to control the progression of myopia, and are currently recognized as one of the methods to control myopia.
What is an OK Mirror?
OK lens is a kind of hard contact lens, the patient wears the lens for 8~10 hours a day, and the rest of the time the eye is in a state of non-myopia or reduced myopia, and the naked eye vision is clear, without wearing any glasses. If the user wears glasses at night, he will not be myopic during the day, which can save him the inconvenience of wearing glasses. For children and adolescents, it can effectively curb the rapid progression of myopia.
Can OK lenses completely treat myopia?
The answer is: NO!
At present, there is no medical treatment for myopia, and laser surgery is only equivalent to cutting a lens on the cornea to correct it. Orthokeratology lenses are only a temporary elimination of myopia, worn every night, during the day is not myopia, most of myopia is caused by the growth of the eye axis, just like the growth of height, there is almost no way to grow taller and shorter.
Is the principle of controlling the growth of the eye axis of the OK lens to shorten the eye axis?
In fact, no, the OK lens flattens the center of the cornea through the effect of fluid mechanics, thereby temporarily reducing the degree of myopia, so that the image falling on the retina forms a state of myopia defocus, so as to delay the growth of the eye axis and control the development of axial myopia.
Children and adolescents are in the period of visual development, myopia is growing rapidly, clinical data show that wearing ordinary glasses, the average annual growth of 75~100 degrees, wearing orthokeratology lenses can be controlled at an average annual growth of 8~25 degrees, wearing glasses and wearing orthokeratology lenses compared with patients, the control effect of orthokeratology lenses is much greater than that of glasses, but due to individual differences, each child's genetic factors, eye habits and eating habits are different, and the control effect is also very different.
There are pros and cons to everything, and the OK mirror is the same, it is a double-edged sword. OK lenses have a definite effect on slowing the progression of myopia, but their potential corneal complications should still be treated with caution. Corneal spotting is the most common complication of wearing contact lenses, which is caused by the poor fitting of the lens, poor tear exchange, lens aging and deformation, poor lens cleaning and sediment, lens scratches and damage, resulting in the deterioration of corneal health.
There is sufficient evidence to show that orthokeratology lenses are an effective method for safely correcting myopia and controlling the progression of myopia. For children and adolescents, orthokeratology lenses can be used as a way to delay the progression of myopia during their developmentally sensitive period. At the same time, in order to ensure the long-term treatment effect of orthokeratology lenses, it is necessary to combine scientific lens wearing, strict compliance of patients, hygienic care of lenses, adherence to routine follow-up, and timely detection and treatment of related complications. In this way, it is possible to maximize the efficacy and safety of orthokeratology lenses for individual treatment.
(The picture comes from the Internet)