Objective. To establish an automated visual acuity test (AVAT) for infants, based on preferential looking technique and controlled with remote eye tracking. To validate the AVAT in a group of healthy children. To compare AVAT visual acuity (VA) values with corresponding VA values, acquired with standard tests (ST).
Methods. ST, adapted for age (Keeler acuity cards in preverbal children, LEA symbols in verbal children), was performed to obtain monocular VA in a group of 36 healthy children. During AVAT, nine different stimuli with grating circles that matched spatial frequencies of nine Keeler acuity cards (raging between 0.29–14.5 cycles per degree) were projected on a screen. Three repetitions of each stimulus were showed during nine-second intervals, interchanging with an attention grabber. The remote eye tracker was used to evaluate the proportion of time a child spent looking at each grating circle compared to a homogenous grey background that matched the grating stimuli in average luminance. From this proportion of time child's binocular VA was evaluated.
Results. 97 % (35/36) of healthy children successfully completed ST and AVAT. There was an agreement between the results of a ST and AVAT, Lin’s concordance coefficient being 0,53 (95% CI= 0,31–0,72). A tendency was observed towards VA overestimation on AVAT for children with VA> 0.4 logMAR on ST and towards VA underestimation on AVAT for children with VA ≤ 0.4 logMAR on ST.
Conclusions. AVAT requires a minimally skilled investigator. The evaluation of better eye monocular VA on ST and binocular VA on AVAT were comparable for healthy children.
Shortened Measurement Time of Functional Visual Acuity for Screening Visual Function
