Visual field analyser: assessment of delay and temporal resolution of vision

Visual changes mediated by beer in retrobulbar neuritis--an investigative case report

A patient with established retrobulbar neuritis and Uhthoff's phenomenon who claimed that his visual acuity improved after drinking beer was assessed by detailed quantitative psychophysical tests. Studies of electrophysiological responses and biochemical levels of blood serum before and after drinking on several occasions were also made. The results of tests of contrast sensitivity, spectral sensitivity, flicker sensitivity, and visually evoked potential confirmed his observation. Some mechanisms for this phenomenon are considered.

Effect of body temperature on visual evoked potential delay and visual perception in multiple sclerosis

Seven multiple sclerosis patients were cooled and four heated, but evoked potential delay changed in only five out 11 experiments. Control limits were set by cooling eight and heating four control subjects. One patient gave anomalous results in that although heating degraded perceptual delay and visual acuity, and depressed the sine wave grating MTF, double-flash resolution was improved. An explanation is proposed in terms of the pattern of axonal demyelination. The medium frequency flicker evoked potential test seems to be a less reliable means of monitoring the progress of demyelination in multiple sclerosis patients than is double-flash campimetry or perceptual delay campimetry, although in some situations the objectivity of the evoked potential test would be advantageous.