From Big Medical Encyclopedia

AMBLYOPIA (amblyopia; Greek amblys — weak and opsis — sight) — the decrease in sight caused by functional frustration of the visual analyzer.

On an etiological sign distinguish several types And.: disbinokulyarny, obskuratsionny, anizometropichesky, refraction, hysterical. Some authors allocate And. inborn and And. from non-use.

Disbinokulyarny amblyopia, as a rule, unilateral, arises owing to disturbance of solid vision, hl. obr. at monolateral squint. The pathogenetic basis it is made by permanent braking of function of the central sight of the rejected eye. His visual acuity considerably goes down, usually to 0,2 — 0,1 and less. Ability of an eye to distinguish distinction in brightness of the considered objects at the same time does not suffer that indirectly indicates the cortical level of localization of brake process. Quite often central pole of a retina loses the functional superiority before other sites of a retina. There is the wrong visual fixing and false space localization of the objects considered by one ambliopichny eye. Also lowered ability of the last to distinguish close located signs is often noted.

Obskuratsionny amblyopia arises at inborn or early the acquired keratoleukomas or a crystalline lens. Diagnosis obskur atsionyy And. it is put in cases when the lowered sight remains, despite elimination of these opacifications and lack of anatomic changes in back department of an eye. Because of early functional inaction also structural formation of the visual analyzer is late. Therefore even during the use of modern methods of treatment obskuratsionny And. its results are low.

Anizometropichesky amblyopia. Its reason is put in inability of the visual analyzer to perceive as uniform images on retinas of both eyes because of a big difference in the size and clarity of these images. At big degrees of a heterometropia (5 dptr and more) the visual system of an eye with the worst refraction sharply lags behind in development, and it is not possible to increase visual acuity practically. If the difference in a refraction of both eyes is not really considerable, then timely optical correction and the corresponding lgecheniye can significantly increase visual acuity of an ambliopichny eye and recover solid vision.

Refraction amblyopia arises at continuous and long projection on a retina of not clear images of objects, hl. obr. at high far-sightedness and an astigmatism. Diagnosis refraction And. it is put on the ground that anomalies of a refraction during inspection do not give in to optical correction, carrying is correct the chosen glasses leads to substantial increase of visual acuity up to normal.

Hysterical amblyopia represents one of forms of display of hysteria, at a cut subcrustal functions prevail over cortical. At hysterical And. easing or total loss of sight, disturbance of color sensation, narrowing of fields of vision, scotomas and hemianopsias, hypo - and a hyperesthesia of skin a century, a cornea, a photophobia, dacryagogue, an ophthalmoplegia, rigidity of pupils, spasms of accommodation and convergence, a ptosis, a nictitating spasm, dissociation of movements of eyes, pseudoparalyses of oculomotor muscles can be observed. Duration of process — from several hours to many months. The diagnosis is difficult, especially in cases when decrease in sight — the only symptom of a disease. It is necessary to exclude any other reason of decrease in sight and to mean lability of symptomatology, airs and graces and fancifulness of poses of patients at a research, a pliability to suggestion and effective action of psychotherapy.

The terms «inborn amblyopia» and «amblyopia from non-use» which are a little capturing the essence of process now are almost not applied.

Treatment — see. Squint .

Bibliography: Avetisov E. S. Disbinokulyarnaya amblyopia and its treatment, M., 1968, bibliogr.; Pilman N. I. Functional treatment of squint at children. Kiev, 1964, bibliogr.; Bangerter-Vlaser A. Amblyopiebehandlung, Basel — N. Y., 1955; Cüppers C. Grenzen und Möglichkeiten der pleoptischen Therapie, in book: Schielen, hrsg. v. F. Hollwich, S. 1, Stuttgart, 1961.

Z. S. Avetisov.