Psychophysical flicker thresholds and ERG flicker responses in congenital and acquired vision deficiencies.

Abstract

Psychophysical flicker thresholds and ERG flicker responses were compared with Farnsworth's 100-hue colour test data in cases of congenital and acquired vision deficiences. The results, evaluated in term of sensitivity and specificity lead to some practical and theoretical suggestions. In most cases, flicker responses and colour tests results were better than other classical tests for evaluating the first signs or gravity importance of a macular disturbance. Relatively minor differences between the 3 tests may be related to the observed or supposed extension of lesion in the macular area, but in some cases the observed functional changes can be understood only by admitting some lateral effect from one area to another. Generally acquired colour differences are associated with flicker response changes. In congenital red-green blindness of different gravity, moderate abnormal white light flicker responses could be observed. But they do not seem to be associated clearly with a type and gravity of the deficiency. With coloured stimuli, the difference between normal and red-green colour-blindness is more clear-cut, and red-blind can be discriminated from green-blind. Subclinical retinal pathology as well as specific stimulus conditions in normal and red-green colour-blind subjects reveal some non-linear processes in the low-frequency range of the temporal attenuation characteristics.