Effect of Age and Paradigm on Pediatric Sinusoidal Harmonic Acceleration Testing

This study aims to examine the effect of age and several methodological alterations such as position (parent lap vs. car seat), calibration strategy (standard vs. default), and illuminance on sinusoidal harmonic acceleration (SHA) outcomes in children aged 6 months to 5 years.

Fifty-two healthy children, aged 6 months to 5 years, and 23 healthy adults, aged 22 to 39 years, participated. To assess the effect of light illuminance on the corneoretinal potential, adults completed SHA at 0.16 Hz immediately, 5 and 10 min after the rotary chair door was closed, and then again after 10 s of light illumination. To assess the effect of position and calibration strategy, adults completed SHA using default and standard calibration in a standard seat and in a forward seat position. In children, SHA was completed at 0.01, 0.04., and 0.16 Hz in a car seat or booster seat and in a parent's lap, if tolerated.

Gain decreased with darkness adaptation and significantly increased in response to using a light wand. In the adults, gain was higher regardless of test position using default calibration and significantly lower in forward seat position using standard calibration; however, in the pediatric group, there were no significant differences in outcomes relative to age or position. Overall, children had significantly higher gain, phase, and symmetry when compared to the adults.

SHA testing is feasible using a combination of conditions without significantly affecting interpretation. Pediatric SHA test outcomes were higher compared to those of adults, supporting the need for pediatric normative data.