Clinical and ocular motor analysis of the infantile nystagmus syndrome in the first 6 months of life.
OBJECTIVE
The infantile nystagmus syndrome (INS) usually begins in infancy and may or may not be associated with visual sensory system abnormalities. Little is known about its specific waveforms in the first 6 months of life or their relation to the developing visual system. This study identifies the clinical and ocular motility characteristics of the INS and establishes the range of waveforms present in the first 6 months of life.


METHODS
27 infants with involuntary ocular oscillations typical of INS are included in this analysis. They were evaluated both clinically and with motility recordings. Eye movement analysis was performed off line from computer analysis of digitised data. Variables analysed included age, sex, vision, ocular abnormalities, head position, and null zone, neutral zone characteristics, symmetry, conjugacy, waveforms, frequencies, and foveation times.


RESULTS
Ages ranged from 3 to 6.5 months (average 4.9 months). 15 patients (56%) had abnormal vision for age, nine (33%) had strabismus, five (19%) had an anomalous head posture, 13 (48%) had oculographic null and neutral positions, nine (33%) had binocular asymmetry, and only two showed consistent dysconjugacy. Average binocular frequency was 3.3 Hz, monocular frequency 6.6 Hz. Average foveation periods were longer and more "jerk" wave forms were observed in those patients with normal vision.


CONCLUSIONS
Common clinical characteristics and eye movement waveforms of INS begin in the first few months of infancy and waveform analysis at this time may help with both diagnosis and visual status.
Hertle
R W
RW
Pediatric Ophthalmology, Columbus Children's Hospital, OH 43205, USA. hertler@chi.osu.edu
Maldanado
V K
VK
Maybodi
M
M
Yang
D
D
D005133:Eye Movements; D005260:Female; D019416:Head Movements; D006801:Humans; D007223:Infant; D008297:Male; D020417:Nystagmus, Congenital / Q000175:diagnosis / Q000503:physiopathology*; D013577:Syndrome; D014786:Vision Disorders / Q000503:physiopathology*; D014792:Visual Acuity