37 Diagnostic Evaluations: Autism Spectrum Disorder
The complexity of assessing autism
Assessing for autism in blind and low vision children is challenging. Autism can be present in blind and low vision children independent of their visual impairment, or autism and the visual impairment may both be due to an underlying condition impacting brain involvement. In addition, features that appear similar to autism can also be present secondary to the visual impairment as sensory deprivation and environmental risk factors may impact social-cognitive development.
Commonalities
Autism is diagnosed based on behavioral presentation, including differences in social interaction, social communication, repetitive behaviors, and restricted interests. Some traits are commonly seen in blind and low vision children and autistic children without visual impairment:
- Reduced visual joint attention (i.e., mutual gaze between the child, another person, and an object). Joint attention is a foundation for the development of attachment, language, and learning about the self and others.
- Reduced social interactions. Blind and low vision children respond less often with smiling, pointing, and joint attention. Engaging less in interactions with caregivers can be interpreted as a lack of interest, leading to a decrease in positive social exchanges over time.
- Difficulty with social pragmatic skills. Pragmatic skills include appropriately using eye contact and interpreting nonverbal messages.
- Difficulty with pronoun usage. Challenges include a late start at using pronouns and more reversal errors.
- Difficulty in learning about theory of mind. Theory of mind is the understanding of the thoughts and emotions of others via observation of the facial expressions and body movements of others.
- Stereotyped movements and behaviors. Blind and low vision children may engage in stereotyped movements and behaviors, particularly visual self-stimulatory behaviors, including eye-poking/pressing/rubbing, light gazing, and flicking fingers in front of eyes. There may also be repetitive motor movements.
- Echolalia, learning and using whole word phrases for specific contexts and activities.
- Socially inappropriate questions.
Specialized and modified tools
The tools used to evaluate autism may not be appropriate for blind or low vision children without modification. A 2024 scoping review (Stevenson & Tedone) outlined various specialized and modified tools for evaluating autism. Two of the most well researched and supported measures for direct semi-structured observations are described here.
The Autism Diagnostic Observation Schedule, Second Edition (ADOS-2®; Lord et al., 2012) is a semi-structured, play-based measure which was modified and validated for blind and low vision children (Dale et al., 2024). Using the modified ADOS-2® (Module 3), the authors developed a new “visual impairment diagnostic algorithm” which showed high sensitivity and specificity against clinician formulation.
De Vaan and colleagues took another approach, modifying a tool designed to evaluate individuals with deafblindness and profound intellectual disability (Hoevenaars-van den Boom et al., 2009) to work with individuals with visual impairment. The new tool is the Observation of Autism in People with Sensory and Intellectual Disabilities (OASID; de Vaan, Vervloed, Peters-Scheffer, et al., 2016; de Vaan et al., 2018; de Vaan, Vervloed, Knoors & Verhoeven, 2019. The OASID is designed for individuals with moderate to profound intellectual disabilities, combined with visual impairments or deafblindness and is available for free. The authors provide a review of studies supporting the OASID (de Vaan, G., & Vervloed, M. P. J., 2021).
Recommendations
To evaluate for autism in low vision or blind children, the examiner must have extensive knowledge of the typical developmental trajectory in blind and low vision children and what is considered consistent with autism rather than typical behavior. Two recent articles provide a review of autistic-like features in blind and low vision students – “Autistic-Like features in Visually Impaired Children: A Review of Literature and Directions for Future Research” (Molinaro et al., 2020) and “Considerations for the differential diagnosis of ASD in medically complicated pediatric populations” (Ludwig et al., 2022).
The examiner must carefully analyze behaviors to differentiate behaviors reflective of interest without opportunity and behaviors that reflect a lack of interest or skill despite opportunity and support. The examiner must consider whether the student has had direct instruction to promote the development of social skills. For example, without the ability to scan a room, identify current or potential friends, or read facial and body language, it is particularly challenging for blind and low vision individuals to initiate social behavior. Both youth with autism and youth with visual impairments may have the desire to interact with others but need support to do so. Blind and low vision students without additional needs may respond quickly to social skill interventions.
Differential diagnosis can be challenging, particularly when students are very young since there may not have been opportunities for intervention. Young blind students may present with frequent repetitive, stereotypical behaviors that diminish as they grow older (reviewed in Stevenson & Tedone, 2024). The diagnosis of autism may be provisional or deferred as the response to intervention is monitored.
In school, the blind or low vision student may already be eligible for special education services under the “visual impairment” category. In the United States (and many Canadian provinces), if assessment identifies an area of need for services or support, such as for direct instruction on social skills, those services must be provided. A secondary designation of autism may not be required for school services, though a diagnosis of autism can provide additional access to services in the community.
References
Dale, N., Sakkalou, E., Eriksson, M. H., & Salt, A. (2024). Modification and validation of an Autism Observational Assessment Including ADOS-2® for use with children with visual impairment. Journal of Autism and Developmental Disorders, 10.1007/s10803-024-06514-z. Advance online publication. https://doi.org/10.1007/s10803-024-06514-z
de Vaan, G., & Vervloed, M. P. J. (2021). OASID, an Instrument for Assessing Autism Spectrum Disorders in Individuals with Intellectual Disabilities Combined with Visual Impairments or Deafblindness. Journal of Visual Impairment & Blindness, 115(2), 134-142. https://doi.org/10.1177/0145482X211000965
de Vaan G., Vervloed M. P. J., Peters-Scheffer N. C., Van Gent T., Knoors H., Verhoeven L. (2016). Behavioural assessment of autism spectrum disorders in people with multiple disabilities. Journal of Intellectual Disability Research, 60(2), 101–112. https://doi.org/10.1111/jir.12206
de Vaan G., Vervloed M. P. J., Peters-Scheffer N. C., Van Gent T., Knoors H., Verhoeven L. (2018). Assessing autism spectrum disorder in people with sensory impairments combined with intellectual disabilities. Journal of Developmental Physical Disabilities, 30(4), 471–487. https://doi.org/10.1007/s10882-018-9597-x
de Vaan G., Vervloed M. P. J., Knoors H., Verhoeven L. (2019). OASID: Observation of Autism in people with sensory and intellectual disabilities. Manual. www.gittadevaan.nl/OASID
Hoevenaars-van den Boom M. A. A., Antonissen A. C. F. M., Knoors H., Vervloed M. P. J. (2009). Differentiating characteristics of deafblindness and autism in people with congenital deafblindness and profound intellectual disability. Journal of Intellectual Disability Research, 53(6), 548–558. https://doi.org/10.1111/j1365-2788.2009.01175.x
Lord C., DiLavore, P.C., Gotham, K., Guthrie, W., Luyster, R.J., Risi, S., & Rutter M. (2012). Autism Diagnostic Observation Schedule, Second Edition (ADOS-2) Manual. Torrance, CA: Western Psychological Services.
Ludwig, N. N., Jashar, D. T., Sheperd, K., Pineda, J. L., Previ, D., Reesman, J., Holingue, C., & Gerner, G. J. (2022). Considerations for the differential diagnosis of ASD in medically complicated pediatric populations. Clinical Neuropsychologist, 36(5), 1049–1068. https://doi.org/10.1080/13854046.2021.2002933
Molinaro, A., Micheletti, S., Rossi, A., Gitti, F., Galli, J., Merabet, L. B., & Fazzi, E. M. (2020). Autistic-like features in visually impaired children: A review of literature and directions for future research. Brain Sciences, 10(8), 507. http://dx.doi.org/10.3390/brainsci10080507
Stevenson, M., & Tedone, E. (2024). Assessment of autism spectrum disorders in children with visual impairment and blindness: A scoping review. Journal of Autism and Developmental Disorders, https://doi.org/10.1007/s10803-024-06300-x
