[Retinal bioelectrical activity in amblyopia]

The mechanisms of visual dysfunction in high amblyopia have not been adequately investigated. Different types of electroretinograms (ERG) as part of the ISCEV standard, as well as macular (15%) pattern and multifocal ERG were recorded in 41 children aged 5-17 years who had high amblyopia with varying gaze fixation and a visual acuity of 0.03-0.1. In high amblyopia, the mixed, macular, and flicker (30 Hz) ERGs were unchanged; however, some patients had supernormal a-wave of a mixed ERG, subnormal a-a- and b-waves of a macular ERG, and a moderately subnormal ERG pattern. Recording of a multifocal ERG showed lower retinal density values in the first and second rings. Thus, in high amblyopia, there are characteristic retinal bioelectrical activity impairments recorded under different conditions of stimulation and adaptation, which suggest that there are impaired interreceptor relations at the retinal level. These changes statistically significantly differ from those in organic retinal defects, which may be a criterion for their differential diagnosis.