Comparison of Eye Tracking and Teller Acuity Cards for Visual Acuity Assessment in Pediatric Cortical/Cerebral Visual Impairment

Abstract

To compare eye tracking and Teller acuity cards (TAC) for assessment of visual acuity in children with cortical, or cerebral, visual impairment (CVI). Reliability and validity study. We recruited 41 children with CVI from a single academic pediatric neuro-ophthalmology clinic. All children performed eye tracking to measure visual acuity, and 26 children completed TAC assessment by a masked examiner. Additionally, 2 pediatric neuro-ophthalmologists graded visual behavior using the 6-level Visual Behavior Scale (VBS). Eye tracking and TAC were performed at baseline and at 1 month. Test-retest reliability of eye tracking and TAC were assessed using the intraclass correlation coefficient (ICC). Eye tracking and TAC visual acuities were correlated with one another and VBS scores using the Spearman correlation coefficient. Test-retest reliability was excellent for eye tracking measurement of visual acuity (ICC=0.81, P < .0001). For pediatric CVI, TAC test-retest reliability was fair (ICC=0.42, P=.04). There was a moderate correlation between eye tracking and TAC (r=0.43, P=.03) and between TAC and VBS score (r=0.50, P=.009), and a strong correlation between eye tracking grating acuity and VBS score (r=0.72, P < .0001). In our cohort of children with CVI, grating acuity measured by eye tracking demonstrated higher test-retest reliability and stronger correlation with pediatric neuro-ophthalmologic assessment of visual behavior than Teller acuity. Objective determination of gaze direction by an eye tracking camera may be more accurate than human assessment in this population. Future research is needed to determine the optimal methods of longitudinal assessment of visual function and functional vision in children with CVI.