[Functional state of visual system in amblyopia].

Amblyopia is a reduction of sight (with optimal optical correction) that is not associated with organic changes of the eye or a visual pathway. Being complex in its pathophysiological mechanisms, amblyopia still remains not completely explored. The purpose of our research was to reveal the symptoms of functional disturbances of visual system at various kinds of a high degree amblyopia. Clinical studies were based on the analysis of results of 72 patients with strabismic and anisometropic amblyopias at the age from 5 to 17 with visual acuity from 0,05 up to 0,2 on the amblyopic eye, and also 10 healthy children. Along with the routine ophthalmological methods of investigation, the psychophysical methods were used in order to study spatial contrast sensitivity (SCS) and color contrast sensitivity ("ON-OFF"). Functional anomalies in amblyopic eyes are characterized by a decrease in spatial contrast, color and contrast sensitivity in a greater degree in paracentral zone (5-10 degrees ), that probably testifies to the localization of the greatest functional changes in this area at the level of retina and does not exclude the possibility of derangement of interreceptor relations at the level of external and internal layers of the retina, as well as afferent inhibitory influence of the central areas of the visual system. Changes in various channels of visual system and topography of these changes help to understand the mechanisms of disturbances of visual functions in amblyopia, can shed light on the localization of functional changes at this pathology and make possible to seek the ways for adequate influence on the visual system.