Early years examination to identify suspect cerebral visual impairment (EYE-CVI): a feasibility study

Early identification of cerebral visual impairment (CVI) is important in providing timely educational support. This study explores the feasibility of early years teachers (EYT) administering in-nursery assessments of visual function.

EYT within six nursery settings were recruited and underwent training and supervision in visual acuity and tablet-delivered visuoperceptual testing (children's visual impairment test; CVIT 3-6). Binocular visual acuity was recorded at 1.5 m and 33 cm. A crowding ratio was calculated if visual acuity was poorer than 0.3 logMAR. Engagement scores were completed to offer insights into areas of testing children found easiest/hardest to engage with.

Four nursery settings completed training and the families of 37 children aged 3-4 years consented to participate; 97% of participants completed acuity testing (mean testing time 5 min) and 86% participants underwent CVIT 3-6 testing (mean testing time 15 min). Mean CVIT 3-6 score was 54.6/70, (expected 10th centile score for age=53). Only 55% children completed all 14 CVIT 3-6 domains. The subtests with poor performance in all three areas (pass rate, completion rate and engagement score) were 'structure from motion', 'missing part' and 'coherent motion'.

Training EYT to administer visual function testing is feasible, in that some elements can be conducted in all children with a reasonably short test time. Further studies are required to identify which visuoperceptual testing domains offer the highest sensitivity/specificity for CVI-related visual dysfunction in this age group.