Understanding the Visual Symptoms of Individuals with Autism Spectrum
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Article Understanding the Visual Symptoms of Individuals with Autism Spectrum Disorder (ASD) Rachel A Coulter, OD, FCOVD, FAAO Nova Southeastern University, College of Optometry ABSTRACT and hand flapping are so intimately associated with Background: Sensory integration problems ASD, that they are used to screen for and to assist are frequently found in individuals with Autism in the diagnose of the condition. A symptom intake Spectrum Disorders (ASD). In particular, vision is form summarizing symptoms associated with these often affected with visual symptoms being pervasive visual differences is provided as a resource. and severe. These visual symptoms are due to an Conclusions: Understanding the link between individual’s unique sensory-processing abilities and visual symptoms and their underlying visual are biologically based in origin. differences is important so that the optometrist who Review: Ninety-six publications, including cares for patients with ASD can accurately gather research studies, case reports, literature reviews and information, complete diagnostic testing, interpret first-hand accounts were reviewed. Visual symptoms results, choose treatments, educate the patient and in individuals with ASD are linked to underlying his or her caregivers and make appropriate referrals differences in the central nervous system including the when necessary. visual system. The concept of Individual-Differences from the Developmental, Individual-Difference, Keywords: autism spectrum disorder, develop- Relationship-based (DIR) model is discussed with mental individual-differences relationship-based (DIR) regard to vision. Visual differences for individuals model, face processing, gaze aversion, gaze shifts, with ASD include photosensitivity, hyper- and hypo- hyper-sensitivity, individual differences, sensory sensitivity, color perception processing, and differences processing, stereotypic behavior, visual processing, in processing central and peripheral stimuli. Face lateral vision, visual differences, visual symptoms processing, gaze shifts, visual integration with other senses, and visual closure are affected as well. It has Introduction also been noted that motion processing, visual-spatial The autism spectrum disorders (ASDs) are a and visual-motor processing and spatial awareness group of developmental disabilities that are char- including visual neglect are also anomalous. Some acterized by significant impairments in social in- visual symptoms such as gaze aversion, lateral vision teraction and communication, as well as repetitive stereotyped behaviors.1 Individuals who have ASD often are affected in their ability to attend, learn and Correspondence regarding this article can be e-mailed to staceyco@nova. edu or sent to Dr. Rachel A Coulter, Nova Southeastern University, College process sensory stimuli. The term spectrum refers of Optometry, 3200 S University Dr, Ft Lauderdale, FL 33328. All to the tremendous variation in how the condition statements are the author’s personal opinion and may not reflect the opinions is manifested. For instance, cognitively those with of the College of Optometrists in Vision Development, Optometry & Vision ASD may range from gifted to severely-challenged, Development or any institution or organization to which the author may be affiliated. Permission to use reprints of this article must be obtained from from talkative to completely non-verbal, and from the editor. Copyright 2009 College of Optometrists in Vision Development. performing independently to needing constant one- OVD is indexed in the Directory of Open Access Journals. Online access is on-one attention. Symptoms of ASD begin before the available at http://www.covd.org. age of 3 years and exist throughout an individual’s life. Coulter RA. Understanding the visual symptoms of individuals with ASD occurs in all racial, ethnic and socioeconomic autism spectrum disorder (ASD). Optom Vis Dev 2009;40(3):164- groups and is four times more common in boys 175. than girls.2 164 Optometry & Vision Development Three areas are evaluated for behaviors consistent Optometrists who serve these individuals need with a diagnosis of ASD:3 to understand visual symptoms associated with ASD. • Social Interaction - decreased eye contact, Given their long-standing tradition of relating vision very little facial expression, an inability to problems to their functional impact, they are uniquely develop peer relationships, and a lack of social positioned to manage these patients. This understanding or emotional reciprocity should include an awareness of visual symptoms often • Communication - marked delay in the devel- associated with ASD, their underlying biological opment of spoken language, being unable to basis when known, and how they may manifest in carry on a conversation, very limited abilities individuals who have ASD. Understanding these to make-believe or show imaginative play symptoms is also important so that the optometrist • Repetitive, stereotyped behavior patterns - can best choose and implement treatment options that inflexibility to changes in routine, repetitive include refractive correction, plus lenses, adds, and motor mannerisms such as lining up objects, yoked prism lenses; as well as colored overlays, colored and marked preoccupation with the parts of lenses, optometric vision therapy, and environmental an object rather than it use as a whole modifications that maximize function in individuals Based upon the history and diagnostic testing, an with ASD. Understanding symptoms is important individual may be diagnosed with one of the ASD so that optometrists can educate caretakers and ASD conditions. These conditions include autistic disorder, individuals themselves as to why these symptoms pervasive developmental disorder - not otherwise occur. Lastly, in some cases, understanding ASD specified (PDD-NOS, including atypical autism), associated symptomology may enable optometrists childhood disintegrative disorder, Rett syndrome to detect these symptoms in undiagnosed individuals and Aspergers syndrome. All of these conditions have and refer them for an evaluation to diagnose or to rule some of the same symptoms, but they differ as to out ASD. onset, severity, and the specific pattern of symptoms. This article provides an overview of visual Public interest and awareness of the needs of in- symptoms found in individuals with ASD. A review dividuals who have ASD has increased as the Center of the literature including published research studies, for Disease Control has measured a marked increase literature reviews, first-hand accounts and texts in the prevalence of the condition up to 1 out of on autism has been completed. A discussion of the every 150 children.4 Recent articles have highlighted underlying basis for visual symptoms is provided. the role of optometrists in caring for individuals with Finally, a symptom intake form is included as a ASD.5,6 These individuals often suffer from symp- resource for gathering information. (See Table 1). toms related to vision and visual processing problems. In addition to symptoms caused by uncorrected ASD and its associated visual differences refractive error, accommodative, ocular motor and The biological basis of ASD are differences in binocular problems; autistic individuals have visual central nervous system structures including the symptoms due to differences in visual perceptual/ cerebellum, cerebral cortex, limbic system, and corpus information processing. Unusual perceptions and callosum as well as the basal ganglia, brain stem and information processing, as well as impairments in neurotransmitters found within these structures.8,9 emotional regulation, have been identified as core Given the extent of the neurological underpinnings of symptoms of ASD.7 the visual system, it is not surprising that a condition The influx of patients diagnosed with autism with widespread differences in brain function would presents a challenge to optometrists. This challenge greatly affect vision function as well. Individuals is due to the large numbers of individuals, the who have autism often have difficulty processing and varying presentation and needs of individuals given integrating sensory information including visual a label of ASD, and the range and intensity of visual information.10 Research of visual symptoms has issues associated with the condition. In addition, shown the symptomology experienced by children many optometrists who may be experienced in with ASD are more severe and complex than those developmental vision and vision therapy may be new found in children who are developing normally. In a to working with this population. comparison of visual symptoms using the Diagnostic Interview for Social and Communication Disorders Volume 40/Number 3/2009 165 Table 1. Visual Symptoms and Individuals with ASD astigmatism equal or more than 1 D or anisometropia equal or more than 1 D.12 Studies of ASD populations Visual symptoms highly associated with ASD show a higher incidence of strabismus.12,13 Scharre ___Gaze aversion and Creedon also found that of the 34 children ___Turning head, looking out of corner of eye evaluated 7 (21 percent) had strabismus. Of the seven ___Being attracted to shiny surfaces or mirrors children who had strabismus, six were exotropic and ___Prolonged fixating on light patterns, windows or blinds one was esotropic. In another study, a parent survey ___Hyperfixating on one object while ignoring other of 7,640 families in 1999 found a reported incidence objects in the room