: Investigation of a New Social Communication Observation Schedule for Assessment of Autism Spectrum Disorder (ASD) in Young Children with Profound-Severe Visual Impairment

Background: Children with congenital profound or severe visual impairment (VI) are at high risk of ASD and social communication difficulties; prevalence of ASD ~30% in several studies. Existing tools used to measure socio-communicative development are highly vision-dependent and not valid for children with VI. A novel visual impairment-social communication observational schedule (VISCOS), drawing on principles of ADOS but specifically designed for 4-7 year olds with profound-severe VI, was developed and initial validation against expert clinician formulation is presented.

Objectives: To investigate the performance of the VISCOS in differentiating children with VI at high risk of ASD and social communication difficulties from those without ASD according to independent expert clinician formulation.

Methods: Preliminary data (45% of planned sample) from forty-five 4-7-years-olds (mean age 5 years 5 months), with congenital disorders of the peripheral visual system with profound VI (PVI, n=7; light perception at best),to severe VI (SVI, n=38, mean 1.00 logMAR).The children engaged in social interaction and play including symbolic play, conversation, auditory story and non-visual theory of mind materials with a trained psychologist assessor, using standard presses designed specifically for children with very low or no vision (VISCOS). Verbal cognition (WPPSI) and vision level (near detection, acuity) were also assessed. The VISCOS assessment was rated by the assessor on the Social Communication difficulties Scale (SCS) and Restricted and repetitive Behaviour Scale (RRBS). A paediatrician with expertise in VI and autism used the video assessments and parent-reported Development and Well-Being Assessment (DAWBA, Goodman et al) to reach a diagnostic formulation (ASD, Social communication difficulties (SCD), Non-ASD) according to DSM-5 criteria.

Results: WPPSI Vocabulary and Information subscales were within the normal range; no significant difference between PVI and SVI subgroup scores. The SCS scores did not differ significantly between PVI and SVI subgroups (U=76.00 p=08), although the scores of the PVI group were more elevated. Negative and stereotyped behaviours (RRBS) were higher in the PVI than SVI group (U=47.50 p=005). The clinician formulation led to 44 children classified as Non ASD (32; 73%), SCD (8; 18%) and ASD (4; 9%). Five out of 7 (71%) children with PVI showed ASD or SCD compared with 9/39 (23%) with SVI. Children rated as ASD or SCD scored significantly higher scores on the SCS (median ASD/ SCD = 14.00; median Non ASD = 6.50; U=44.50, p=.003) and RRBS (median ASD/ SCD = 10.00; median Non ASD = 1.50; U=19.00, p=0001) compared to those with Non ASD. Good sensitivity and specificity was also found (SCS = .70/.71; RRBS = .80/.92 respectively).

Conclusions: This is the most systematic investigation to date developing a new tool for assessing ASD in young children with congenital profound-severe VI. Without involving behaviours or measures that are vision dependent, the new VISCOS showed promising results in relation to identification and diagnosis of ASD or SCD in the context of VI according to expert clinician formulation. Construct validity and the algorithm to identify the most pertinent behaviours related to ASD in young children with VI will also be presented.