The optical system of the normal-sighted eye works in such a way that the cornea and lens bundle light rays in such a way that a sharp image of the environment is created on the retina.
In short-sightedness, the eye is too long so that light is not focused on the retina but in front of the retina; this is known as myopic defocus.
Especially in the first world, more and more children are becoming short-sighted and the trend continues to rise. At present, 10-20% of children in Europe are short-sighted; this is known as school myopia. 25% of these children develop so-called pathological myopia (pathological myopia) later in their lives, which is associated with retinal changes, macular degeneration, glaucoma and retinal detachment.
The development of short-sightedness has not yet been fully clarified, although individual influencing factors are known. These include hereditary components on the one hand and environmental components on the other. Children with a nearsighted parent are twice as likely to become short-sighted themselves as children with normal-sighted parents. If both parents are short-sighted, the risk even increases three to five times. Another factor is the area of application of the eyes, which in our society is shifting more and more from afar to nearby; this is referred to as increasing close work (e.g. reading, smartphone, tablet).
The myopia cannot be reversed, but the progression of myopia can be slowed down or even halted.
Simple tips have been shown to help slow down the development of myopia.
The most effective treatment methods to slow down progressive myopia in children are atropine eye drops and multifocal contact lenses or glasses. The methods can be used individually or in combination to increase the effect.
In children aged 6 to 14 years with progressive myopia (from 0.5 dpt/year), large studies have shown that the progression of short-sightedness can be significantly slowed down by the methods below. For older children, the data is ambiguous, but this does not mean that treatment should be started after 14 years of age.
The mechanism of action of atropine is still not fully understood, but has been proven with several large-scale studies. The use of highly diluted atropine eye drops (0.01%) slows the development of myopia by 30-60% on average. Side effects such as blinding or blurred vision when reading usually do not occur due to severe dilution.
Conventional glasses or contact lenses bring the light rays together in the center of the retina and thus ensure a sharp central image. All around this central image, however, is an unclear image with a so-called hyperopic defocus, i.e. the rays would produce a sharp image behind the retina, but not on the retina.
It is assumed that this hyperopic defocus stimulates the eye to grow in length, i.e. to become more short-sighted. Specially shaped contact lenses allow all light rays to be focused into a sharp image, the growth stimulus is therefore absent and the progression of short-sightedness can be reduced by 25-50%.
There are two types of contact lenses for treating myopia in children:
Corneal infections caused by contact lenses occur only very rarely and can be avoided by using the contact lenses properly.
The principle of multifocal glasses is similar to that of multifocal contact lenses. The eyeglass lens is adjusted precisely to the child's eyes so that the eye goes straight through the optical center. Peripheral light rays pass through more refractive parts of the eyeglass lens, which are arranged in a circle around the optical center. This technology is called Defocus Incorporated Multiple Segments (DIMS). On average, the chances of success are the same as those of multifocal contact lenses, provided that the glasses are worn consistently.
The majority of treated children benefit significantly from the therapy, i.e. the progression of myopia can be slowed down to less than 0.5 diopters per year. In most cases, the therapy can be reduced after a few years and then completely stopped. After the treatment has been suspended, further monitoring should be carried out to ensure that there is no further deterioration.
Only around 12% of treated children respond poorly to the therapy (< 0.5 dpt reduction per year). These so-called “poor responders” can benefit from an increase in atropine dosage (from 0.01% to 0.05%), provided that the side effects are tolerated. Changes in treatment should always be supervised by a doctor to counteract possible side effects.
The progression of myopia is monitored every six months by an ophthalmologist. Two studies are of particular importance. In order to measure the visual defect precisely, accommodation by the ciliary muscle must be switched off. This is done using cyclopentolate eye drops, the effect of which persists for several hours after the examination. Second, eye length is measured and documented using ultrasound biometry. Both tests are painless for the child and safe in terms of side effects.
The atropine eye drops are prescribed by the ophthalmologist for six months at a time.
A specialist optician or optometrist is consulted to adjust multifocal contact lenses or glasses. As a rule, adjusting contact lenses and learning how to handle them requires several visits to the optician.
The abrupt cessation of therapies can lead to an excessive reduction of myopia. The aim of myopia control is to slow down myopia first and then to reduce the therapy in a controlled manner in order to prevent this excessive regression.
The costs of medical examinations are covered by basic insurance. Atropine eye drops are part of the range of services; the costs are borne by health insurance. Basic insurance covers 180.- per year for the adjustment of contact lenses or glasses up to the age of 18 (MiGel 25.01.01.00.1), which only covers part of the optician's total costs.
