The influence of accommodation and fixation on the visual evoked response and visual acuity of normal and amblyiopic subjects

Abstract

Twelve normal and twelve amblyopic subjects were examined to investigate the differences in visual evoked response (VER) as well as the state and influence of the accommodative posture and accommodative response on the VER and visual acuity. The VER amplitudes were shown to be lower in the amblyopic eye a significant proportion of the time, while the implicit times were not significantly different. The accommodative system of the amblyope was shown to differ in both eyes from that of the normal subject, with the amblyopic eye also hypoposturing in comparison to the normal eye of the amblyope. This did not affect the VER or visual acuity significantly. The degree of eccentric fixation had no statistically significant relationship to the VER, accommodative, or visual acuity data. The VER, Haidinger brushes and Maxwell spot were in close agreement for differentiating organic from functional amblyopia