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Ophthalmology, Publication of the section

V.I. Shurkin
(Moscow)

ABOUT SOME MECHANISMS OF REFRAKTO-GENESIS

(рус. / eng.)

This article lists the possible mechanisms of normal and pathological refrakto-genesis, as well as the skeleton of the orbit, which the paper considers the problems from the perspective of the characteristics of the physiology and anatomy of child organism. Shows that the triggering factor of alleged child mechanisms is the nature of the tone of his oculo-motor muscles, and formation the individually refraction and the orbit is three-state and is largely completed in 5-7 years of a child's life.

Keywords: physiologicalfleksorhypertonus(PFH), oculo-motor muscles (OMM), pupil-convergent reflex (PCR), refraktogenesis,skeleton of the orbit, individually refraction, tonus, disostosis

From the moment of birth, the child gets into the natural environment, which has a powerful impact on its intensively growing bodies. Starts the device of an organism to the environment is provided in one form or another throughout the life of the individual. New body signs devolution passed intersect, resulting in complex transformations occur.

During postnatal development identified three critical periods of enhanced growth and change the basic proportions of the body:

     1) early childhood: 1-3 years,
     2) pre-school - 5-7 years,
     3) puberty - 14-16 years.

In parallel with the growth of the organism are age-related changes in all organs and systems. Approximately 20-25 years growth of human ends.

Clinical refraction normal newborn eye corresponds myopia to about 2,0-3,0 D, whereas refraction static hypermetropia corresponds to the same amount. What is this "spasm of accommodation" newborn?

The answer, in our opinion, is contained in the physiological characteristics of an organism of a newborn, one of which is physiological fleksorhypertonus (PFH) skeletal muscle, including oculo-motor muscles (OMM). The influence of hypertonic OMM on elastic eyeball primary (circular) form the past is transformed into the secondary (oval), and optical eye becomes myopia. Obviously, it is the very nature of adaptation to ensure essential for development of infant visual contact with the mother of the typical newborn narrow pupils were evidence of greater vitality subcortical nervous centre pupil-convergent reflex (PCR). In our view, is the first phase of theformation of individual refraction.

PFH abating as skeletal muscle and OMM - to 3-6 month age - optical install eye slowly becomes hypermetropia. The nearest point clear visionremoting, as an adaptation to the environment, allows the baby to expand space to further knowledge of the outside world. Is, in our opinion, is the second phase of the formation individual refraction. For operational settings child's eye a clear vision of the diversity of deleted objects in a range of individual age norms led PCR whereby a reflectory regulation tone OMM and thus the optical eye installation on different distances. This accommodation is important not only to guide the child in the world, but also for the normal development of his eyeballs and orbits.

Fluctuations in the level of muscle tone OMM, ophtalmo-tone and residual linear deformation eyeballs are incentives for the growth and development of normal eyeball refraction. This, in our view, is the third phase of the formation individual refraction, which basically is completed by 5-7 years of a child's life.

Any imbalance muscle tone (hyper- or hypotension, dystonia) OMM as a result generic stimulation in violations (such as cortical and subcortical oculo-motor centers, branches oculo-motor nerves), in our opinion, may continue to have a significant influence on the formation of individual refraction as well as skeletal orbit. Because the tissue of children extremely plastic, for example, hypertension can be manifested in the form of a OMM for congenital myopia, hypotension OMM - in the form of hypermetropia and dystonia OMM - in the form of a type of astigmatism. Violation of skeletal orbit can be manifested in the form of dysostosis.In this regard, the dangerous critical periods-periods of intensive growth of the organism when the risk of violations of normal development is particularly high.

With regard to the development of skeletal orbit baby, from the normal physiology of osseous tissue known as stimulus for bone cell growth is its strong and prolonged tension or compression. This is traction-compression method for jointing of bone fractures of Ilisarov's apparatus. How this becomes feasible in relation to the orbit of the eye?

Movement of eyeballs in orbits are implemented through six OMM: four rectus - superior, inferior, externum and internum, as well as two obliqus - the superior and inferior. All muscles except theobliqusinferior starting from tendenousring, located on the top of the orbit around the optic nerve canal and attached to the sclera of an eyeball. Muscle obliqus inferior originates from the lower inner edge orbit and attached to the sclera behind the equator of the eyeball. Muscleobliqus superior upper tendenous rings and goes up the inside, in the short tendon then tosses a bone block orbit rotates back to eye apple and attached to it behind the equator. This attachment creates an original OMM to orbit "plate", at a voltage of the muscle components which, in our opinion, and a skeletal orbit required compression forstimulation its further growth. Orbit forming as well as individual refraction basically ends in 5-7 years of a child's life.

Any violation of the tone OMM early can lead to the formation of a dysostosis orbit violations of eyeballs (such as exophtalmus, strabismus etc.) and their refraction.

Thus, in our view, can look like possible mechanisms refraktogenesis and formation of skeletal orbit in norm and pathology.

Conclusions.

1. The determining factor of normal refraktogenesis and formation of skeletal orbit a child is tone OMM.
2. Normalrefraktogenesis and formation of skeletal orbit is a three-stage process and is completed by 5-7 years of a child's life.
3. Violation of the tone can be a triggering factor OMM in the development of congenital anomalies of refraction and skeletal orbit in children.

Information about author:

Shurkin V.I. - Ophthalmologist superior.

LITERATURE

1.Zhurba L.T., Mastukova E.M., "Violations of the psychomotor development of children in the first year of life". Moscow, Medicine, 1981.
2.Kozlov V.I. "Human anatomy". Moscow, Sports, 1978.

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