The relationship between symptoms of autism spectrum disorder and visual impairment among adults with intellectual disability.
Congenital blindness nearly triples the chance of meeting autism criteria in adults with ID, so screen for sensory causes before you label.
01Research in Context
What this study did
Kiani et al. (2019) asked if adults with intellectual disability (ID) are more likely to show an autism profile when they are also blind from birth. They looked at records from a large group of adults with ID. They noted who was congenitally blind and who met autism cut-offs on a standard checklist.
What they found
Adults with ID who were born blind were almost three times as likely to score above the autism threshold. This link stayed strong even after the team adjusted for how severe the ID was and for gender. In plain words, blindness itself, not just ID level, pushed autism trait scores up.
How this fits with other research
The result echoes Dammeyer (2014), who saw high autism checklist scores in children with congenital deaf-blindness. Both papers warn that sensory loss can mimic autism traits. It also extends the call from Sasson et al. (2022): if you serve deaf adults with ID, tweak screeners for autism; Reza adds, 'Do the same when clients are blind.' Finally, the finding sharpens the message from Cramm et al. (2009). That team showed vision loss hurts daily skills in adults with ID; Reza shows it also inflates autism phenotype numbers, so screen carefully.
Why it matters
For BCBAs, a high autism score on the ADOS or ABC may reflect sensory barriers, not true autism. When your adult client with ID is congenitally blind, expect autism-like behaviors such as hand flicking or limited eye contact. Before you write 'autism' in the report, rule out sensory causes and consider adapted tools like OASID. This step prevents misdiagnosis and guides better intervention choices.
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02At a glance
03Original abstract
The higher prevalence of autism reported in blind children has been commonly attributed to the confounding effects of an underlying intellectual disability. The aim of this study was to explore the relationship between symptoms of autism and blindness in adults with intellectual disability. We hypothesized that blindness can increase the probability of the autism phenotype, independent of known risk factors, that is, severity of intellectual disability and gender. A general population case register (population size of 0.7 million) was used to conduct two studies. The first study was on 3,138 adults with intellectual disability, using a validated autism risk indicator to study adults with visual impairment. This identified 386 adults with partial and complete visual impairment, both of which were associated with presence of high number of autistic traits (P < 0.001). The second study was only on those with congenital blindness using a standardized assessment tool, the Pervasive Developmental Disorder-Mental Retardation Scale. Those with hearing impairment or unilateral, partial, and acquired visual impairment were excluded. Control groups were randomly selected from those with normal hearing and vision. Prevalence of the autism phenotype was higher among those with congenital blindness (n = 46/60; 76.7%) than their controls (n = 36/67; 53.7%) and this association was statistically significant (adjusted odds ratio = 3.03; 95% confidence interval: 1.34-6.89; P = 0.008). Our results support the hypothesis that a congenital blindness independently affects psychosocial development and increases the probability of the autism phenotype. Early identification of autism could facilitate appropriate psychosocial interventions and educational opportunities to improve quality of life of people with blindness. Autism Res 2019, 12: 1411-1422. © 2019 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Although autism has been commonly reported in those with blindness, it is generally attributed to an accompanying intellectual disability. Current study, however, revealed that congenital blindness is independently associated with symptoms of autism. In spite of its high prevalence, autism can be overlooked in those with intellectual disability and blindness. Improving diagnosis in this population should, therefore, be advocated through raising awareness of this association to facilitate early access to services.
Autism research : official journal of the International Society for Autism Research, 2019 · doi:10.1002/aur.2138