Saccadic strategies in children with hemianopia.
Multiple hypometric (undershooting) saccades are generally reported as a compensatory strategy in adults with homonymous hemianopia. However, hypermetric (overshooting) saccades have been reported to develop spontaneously as a beneficial strategy in response to predictable targets. We examined the saccades of 10 children (aged 5 to 16 years) with homonymous hemianopia to determine the type of compensatory eye-movement strategies employed 6 months to 16 years after hemianopia onset. Homonymous hemianopia was identified using perimetry and/or pattern visual evoked potentials and supported with results of neuroimaging. Eye movements were recorded using bitemporal electrooculography. Saccades were elicited to a red light source in a semipredictable paradigm. We found that hypermetria was not a consistent compensatory strategy in our patients. In spite of the predictability of our paradigm and the long follow-up period, multiple hypometric saccades into the blind field appeared to be the preferred strategy.
Department of Ophthalmology, Great Ormond Street Hospital for Children, London, UK.
L E
LE
Mezey
C M
CM
Harris
F S
FS
Shawkat
C
C
Timms
A
A
Kriss
P
P
West
D S
DS
Taylor
D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D004585:Electrooculography; D005074:Evoked Potentials, Visual / Q000502:physiology; D005133:Eye Movements / Q000502:physiology; D005260:Female; D005500:Follow-Up Studies; D006423:Hemianopsia / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology*; D006801:Humans; D008297:Male; D012438:Saccades / Q000502:physiology*; D058609:Visual Field Tests; D014794:Visual Fields / Q000502:physiology