RESULTS A total of 45 females and 38 males (mean age 3y 5mo; range 10mo-6y 10mo) with ONH or SOD and profound visual impairment (PVI) or severe visual impairment (SVI) were assessed. A total of 58% of children had at least one SCRR difficulty, and 31% had a clinical diagnosis of ASD. The prevalence of ASD was slightly higher in children with SOD than in children with ONH (36% vs 26%) also slightly more frequent in children with PVI than in children with SVI (36% vs 27%). The prevalence of SCRR difficulties was statistically higher in children with PVI than in children with SVI (p=0.003). Clinical ASD was most likely to be diagnosed between 2 years 4 months and 4 years 6 months. Development was significantly delayed in children with ASD compared with children without social communication difficulties (p=0.001).