Abstract
Purpose :
Knowledge of the time-course for normal development of the retina and the acquisition of normal age-related data is essential to detect, monitor, and understand disease processes that affect the pediatric retina. In the present study, we characterize DA ISCEV standard ERGs in children compared to adults.
Methods :
In this cross-sectional study, we recruited 20 participants of European descent with normal ocular and general health including 10 children between 7 and 12 years old and 10 young adults between 20 and 33 years. Following 20 minutes of dark adaptation, ERGs were recorded simultaneously in each eye from thread electrodes (DTL® fiber) using the Espion E3 System with fully dilated pupils (0.5% tropicamide). Three ISCEV standard stimuli were used: DA 0.01, DA 3 and DA 10 ERGs. We measured a- and b-wave amplitudes and implicit times. Using the average of the right and left eye values, we compared age groups and considered pigmentation levels based on iris colour.
Results :
ERG implicit times for both a- and b-waves were shorter in the children than in the adults across stimuli (mixed ANOVA, p<0.0005 and 0.003, respectively); this did not interact with eye colour. ERG amplitudes did not differ between the children and the adult groups. However, b-waves were larger across all stimuli in those with blue irides compared with green, hazel or light brown irides (mixed ANOVA p=0.0021). For a-waves, the trend to larger amplitudes in those with blue eyes did not reach significance (p=0.065).
Conclusions :
Although ERGs in very young infants are characterized by longer implicit times, children aged 7-12 years show shorter DA implicit times than those of adults, possibly indicating immaturity in the rod system. It has been shown previously that darker irides result in lower ERG amplitudes, but we show that even within the lightly pigmented people of European descent, ocular pigmentation is associated with differences in ERG amplitudes.
This is a 2020 ARVO Annual Meeting abstract.