Learn More
BACKGROUND/AIMS Past studies have explored some of the associations between particular motor and sensory characteristics and specific categories of non-neurological infantile nystagmus. The purpose of this case study is to extend this body of work significantly by describing the trends and associations found in a database of 224 subjects who have undergone(More)
Using infra-red oculography, electro-oculography and fundus video-recordings, waveform characteristics (amplitude, frequency, waveform shape and foveation) were examined in over 150 individuals with congenital nystagmus. For many of the subjects the nystagmus exhibited marked variability in both space and time. The sources of this variability were explored(More)
PURPOSE To link psychophysical thresholds for blind spot awareness and filling-in with early neural components that underpin these perceptions. METHODS Blind spot dimensions were quantified, after which an intrinsic stimulus (i.e., a rectangular bar of varying length centered within the blind spot) was used to determine blind spot awareness and filling-in(More)
PURPOSE To determine the relationship between retinal image movement (RIM) and oscillopsia in subjects with idiopathic congenital nystagmus (CN). METHODS Eye movements were recorded using an IRIS infrared system. The eye movement signal was fed back to move an otherwise stationary target on a screen and thereby modify the RIM experienced by each of the(More)
Primary gaze fixation in healthy individuals is frequently interrupted by microsaccades and saccadic intrusions (SI). The neural systems responsible for the control of attention and eye movements are believed to overlap and in line with this, the behaviour of microsaccades appears to be affected by exogenous and endogenous attention shifts. In the current(More)
Dynamic overshoots are seen after voluntary re-fixation saccades. They are microsaccadic movements which follow primary saccades and have no delay. The purpose of this study was to examine the prevalence and metrics of the dynamic overshoots seen after involuntary saccades. Using infra-red oculography we demonstrate that dynamic overshoots are a common(More)
Congenital nystagmus is an oculomotor disorder in which fixation is disrupted by rhythmical, bilateral involuntary oscillations. Clinically these eye movements have been described with some degree of success in terms of their peak-to-peak amplitude, frequency, mean velocity and waveform shape. However, it has not proved possible to diagnose any underlying(More)
Models of the mechanisms of normal eye movements are typically described in terms of the block diagrams which are used in control theory. An alternative approach to understanding the mechanisms of normal eye movements involves describing the eye movement behaviour in terms of smooth changes in state variables. The latter approach captures the burst cell(More)