Abstract
Purpose :
Visual Acuity (VA) is a primary endpoint in pediatric eye care; however, standard VA tests must be administered by a trained examiner in clinic and often require repeat visits to assess visual development and response to treatment. The novel self-administered AIM (Angular Indication Measurement) VA offers an alternative to assess acuity in a pediatric population with potential for home-based, efficient and accurate measurement. Here, we evaluate its utility to measure VA in children with and without amblyopia.
Methods :
Monocular VA was measured in 24 subjects (9 females, mean age 9 ± 2 years, 13 controls and 11 amblyopes) with Snellen at distance, Rosenbaum at 40cm, and AIM VA at 40cm. AIM VA comprises a sequence of 3 charts, each containing a 4*4 grid of 6° cells displayed on a tablet with a white background (131 cd/m2). Each cell contained a dark (0.5 cd/m2) Landolt-type C optotype that was randomly oriented and varied in size, spanning a size range adapted to the participants’s performance (Figure 1). Participants indicated the orientation of each C by touching the corresponding location on a surrounding ring, eliciting an auditory ‘pop’ sound. Angular error between true and reported C-orientation was recorded. On subsequent charts, prior performance was used to select a range of difficulty for each participant. ANOVAs were used to compare VA across methods, groups, and eyes.
Results :
AIM median test duration was 95 sec (SD=44 sec) for each eye. Runs in which a participant selected random orientations were excluded, resulting in the inclusion of 17 amblyopic and 13 control eye runs. A main effect for method was found (3-Way-ANOVA: p<0.001) when comparing acuity results across groups, methods, and eyes. A two-way ANOVA of interocular VA differences revealed no significant difference across methods, with a trend of larger interocular differences in amblyopes compared to controls.
Conclusions :
AIM VA can be self-administered by children as young as 5 years in around 1.5 minutes. AIM VA demonstrated good agreement with standard VA tests and identified interocular VA differences in children with amblyopia. AIM may be a useful tool to monitor amblyopia and pediatric eye disorders that require VA monitoring, particularly those that involve assessment of interocular differences.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.