We wished to study how the severity and duration of early onset visual deprivation affects eye alignment and ocular stability. Thirty-three patients (aged 1 week to 12.8 years) with infantile cataracts (16 bilateral, 17 unilateral) were examined for periods up to 61 months. Twenty-three patients were considered to have cataracts, which were a major obstacle to vision (major form deprivation), 9...

To understand to what extent visual-pattern deprivation during infancy results in strabismus and nystagmus, the authors examined the long-term consequences of this type of deprivation in monkeys during the first 50 days of life. Three cynomolgus and three rhesus monkeys had the eyelids sutured closed within 24 hr of birth. At 25 days of age, the eyelids were opened, and the eyelids of the fello...

The objective of this study was to describe the role of electrical stimulation in controlling peripheral vertigo. In a prospective study on 13 healthy volunteers, nystagmus was induced with caloric stimulation and the interval of nystagmus disappearance was recorded. This time indicates the basal response of vestibular end-organ. After caloric irrigation, pulsed signal was applied for each...

The Hyperventilation Test is widely used in the "bed-side examination" of vestibular patients. It can either activate a latent nystagmus in central or peripheral vestibular diseases or it can interact with a spontaneous nystagmus, by reducing it or increasing it. Aims of this study were to determine the incidence, patterns and temporal characteristics of Hyperventilation-induced nystagmus in pa...

Our objective was to translate the past 40 years of infantile nystagmus syndrome (INS) research (i.e., ocular motor recording and control-systems analysis) into a therapeutic approach. Our eye movement recordings use infrared reflection, mag­ netic search coil, and high-speed digital video sys­ tems. Each eye was calibrated during monocular fixation (fellow-eye occluded). We analyzed and displa...

Background: Benign paroxysmal positional vertigo (BPPV) is the most common cause of vertigo and nystagmus in clinics. Vertigo has many causes and the recurrence of vertigo is unknown. Among a lot of factors, vitamin D deficiency is more important. This study was conducted to determine the effect of vitamin D supplementation on torsional nystagmus in BPPV patients. This study wants to show the d...

Latent nystagmus (LN) is the by-product of fusion maldevelopment in infancy. Because fusion maldevelopment--in the form of strabismus and amblyopia--is common, LN is a prevalent form of pathologic nystagmus encountered in clinical practice. It originates as an afferent visual pathway disorder. To unravel the mechanism for LN, we studied patients and nonhuman primates with maldeveloped fusion. T...

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 occurrence in physiological square-wave je...

Latent/manifest latent nystagmus (LMLN) is a jerk nystagmus with a decreasing-velocity or linear slow phase whose fast phase is in the direction of the fixating eye. Change of the fixating eye by alternating tropias or cover will cause reversal of the LMLN to preserve this relationship. In the dark, where no fixation is possible, the fast phases of LMLN are in the direction of the intended fixa...

The normal development and the capacity to calibrate gaze-stabilizing systems may depend on normal vision during infancy. At the end of 1 yr of dark rearing, cats have gaze-stabilizing deficits similar to that of the newborn human infant including decreased monocular optokinetic nystagmus (OKN) in the nasal to temporal (N-T) direction and decreased velocity storage in the vestibuloocular reflex...