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.