METAMORPHOPSIA

From Big Medical Encyclopedia

METAMORPHOPSIA (Greek metamorpho[sis] transformation, transformation + opsis sight) — the distorted vision of objects of the world around. The m arises at irritation of a peripheral part of the visual analyzer (see), representing to a greater or lesser extent bent, reduced (at a micropsia) or increased (at a macropsia) display of real-life objects of the world around.

M.'s phenomena should be distinguished from the subjective visual feelings noted investigated in an eye in response to various influences (see. Entoptichesky phenomena ), and also of the presents visual hallucinations (see).

All cases of M. depending on an origin can be subdivided into the refraction M. caused by optical features of a structure of an eye and receptor M., a cut certain anatomic changes from the device of a mesh cover of an eye perceiving light are the cornerstone (see. Retina ).

Especially often M. in the form of a micropsia is observed at paresis or paralysis of accommodation. In these cases for implementation of accurate perception of close located objects the patient should strain strongly a ciliary muscle therefore the fixed objects are presented to it located closer, than it takes place actually. According to it all objects seem to it at the same angular sizes less large. Emergence of a micropsia at the nek-ry young people having far-sightedness can be similarly explained. The return phenomenon is observed at children at a resistant spasm of accommodation. In the conditions of such spasm of the child rather mostly insignificant boost of accommodation for accurate distinguishing of close objects why they seem located further from an eye, than actually and consequently (at the same angular sizes), big, than actually.

Fast changing of a refraction of an eye, napr, at a traumatic rupture of tsinnovy sheaves (the general tendinous ring, T.) or at nek-ry general intoxications, can lead to the wrong judgment of the valid size of visible objects — to emergence at patients of a micropsia or macropsia.

The receptor form M. meets at diseases of a retina of an eye. One of the most important symptoms of defeat of area of a macula lutea is the curvature, distortion of a form and the sizes of the fixed objects. M.'s symptom at poppy ulita is observed most often in a stage of scarring of a retina. The similar phenomena of M. are observed sometimes at is central the located amotio of a retina, nek-ry exudative choroidites, melanoblastomas of macular or paramacular area.

Treatment of a basic disease is carried out, manifestation to-rogo is the M.



Bibliography: The multivolume guide to eye diseases, under the editorship of V. N. Arkhangelsky, t. 2, book 2, page 506, M., 1960; Lehrbuch und Atlas der Augenheilkunde, hrsg. v. H. Pau, Stuttgart, 1973.


A. Ya. Samoylov.

Яндекс.Метрика