Comparison of a novel optokinetic nystagmus system with Teller Acuity Cards in young children.

Abstract

Purpose : To compare a novel optokinetic nystagmus resolution acuity test (Vifant VISTA) to Teller Acuity Cards (TAC) in young children with and without abnormal eye exams.

Methods : 69 children, 6 to 36 months (mean 19.7 ±9.4) who had eye exams to determine presence or absence of vision disorders were tested with binocularly and monocularly with VISTA and TAC. VISTA uses a commercial tablet computer OKN stimulus and video capture. Black and white gratings in 4 increments from 0.2-2.4 cycles per degree (CPD) separated by animated cartoons were presented for 5 seconds each at a rate of 10 degrees per second. Masked trained video graders quantified pursuit and saccadic eye movements. TAC procedure was performed in the same setting.

Results : 26 children (37.7%) had one or more vision disorders. Using age-specific norms for TAC, 29% of children had reduced binocular and 53.6% reduced monocular visual acuity. TAC sensitivity to detect vision disorders was 50% (95% CI:32.1-67.9%) binocularly (83.7% specificity, 95% CI:70.0-91.9%) and 69.2% (95% CI:50.0-83.5%) monocularly (specificity 55.8%, 95% CI:41.1-69.6%). Optimizing age-specific cut points, sensitivities of 73.1% (95% CI:53.9-86.3%) (55.8% specificity, 95% CI:53.9-86.3%) were found with VISTA binocular pursuits measures. Best sensitivities improved to 84.6% (95% CI: 66.5-93.9%) by combining the 2 lower spatial frequencies (0.2 and 0.8 CPD) (specificity 41.9%, 95% CI: 28.4-56.7%). Children with normal monocular TAC vision had more measurable monocular pursuits on VISTA compared to children with abnormal TAC (11.2 vs 8.4; p=0.03). Differences were also found combining the 2 lower spatial frequencies for monocular pursuits (7.9 vs 4.6; p<0.002) or saccades (5.9 vs 4.1; p<.02). Children with normal binocular TAC had more measurable binocular pursuits only at the lowest spatial frequency (3.5 vs. 2.6; p<.048) or by combining the 2 lowest spatial frequencies (6.8 vs. 5.1; p<.03).

Conclusions : VISTA showed higher sensitivities and lower specificities compared to TAC in identifying children at risk for vision disorders in this small sample. Sensitivities and specificities for monocular TAC and binocular VISTA pursuits were similar. Monocular pursuits at lower spatial frequencies were best able to differentiate children with reduced TAC vision. Incorporation of automated eye tracking may allow real-time detection of very young children at risk for vision disorders.

This is a 2020 ARVO Annual Meeting abstract.