Eyeing the connection between autism and vision – Spectrum
♫ Friday, September 18th, 2020The first indication that autism can accompany blindness more often than expected came in a 1956 study of 60 children with retinopathy of prematurity, a condition in which the light-capturing tissue at the back of the eye does not develop properly. Five of these children turned out to be autistic a dramatic result at a time when fewer than 1 in 1,000 children had an autism diagnosis, and high even in light of todays prevalence of about 1 to 2 percent in most countries.
Since then, studies in multiple countries have documented a double-digit prevalence of autism among blind children: 12 percent in Turkey, 17 percent in Sweden and 50 percent of the students whom Jure examined at the school for the blind Gigena attended in Argentina.
These studies are small, each involving only a few dozen to a few hundred people. But a much larger study published this year also links autism and a lack of sight. Researchers in Scotland approached the question from the opposite direction: They combed through national census data on 5.3 million people to show that blindness is about three times as common in autistic children as in their typical peers, and it occurs in autistic adults at 1.5 times the typical frequency.
None of the studies explain the statistics. Do autism and blindness stem from the same biological roots? Some research suggests that autism is closely tied to specific causes of blindness for instance, optic nerve hypoplasia (Gigenas condition), retinopathy of prematurity and anophthalmia (in which one or both eyes fail to develop). The causes of these vision problems may also contribute to autism, experts say.
Lilita wasnt reaching [milestones]. She wasnt making friends, and she didnt communicate well. Lilian Funes
Another possibility is that blindness contributes to autism traits, particularly when a child is born blind, because vision is thought to be critical to the early development of social skills. Young children learn that other people have distinct points of view and emotions by seeing how others react to the world around them. They also learn about social cause and effect through visual relationships, such as when a toddler grabs a toy and pulls it to himself while saying, Mine.
What you have here is something absolutely pivotal for human development, says Peter Hobson, emeritus professor of developmental psychopathology at University College London in the United Kingdom. Children with acquired blindness can still tap this knowledge after they have lost their sight, Hobson says. But those who are born blind may have trouble gaining it in the first place.
This theory is borne out by research showing an association between congenital blindness and autism. For example, 18 of 25 students with congenital blindness at Gigenas school met the criteria for autism in Jures 2016 study, compared with only 1 of 13 with partial or acquired blindness. A similar pattern emerged when he analyzed pooled data from 12 published studies of blindness and autism. The presence of total congenital blindness was the main factor by far that produced autism, he says. Blindness acquired after the first year of life and partial vision were associated with autism less frequently.
In a 1997 study of British schools for the blind, Hobson and his colleagues found that 9 of 24 congenitally blind children without obvious neurological impairments met the criteria for autism; many others had autism traits. Those findings jibe with Jures clinical experience: Within families, children who are completely blind tend to be autistic, whereas their seeing or partially sighted siblings, even identical twins, are not, he says. Im completely convinced that blindness itself conveys a huge possibility of autism.
Researchers who work with blind children have also noticed similarities between their behavior and that of autistic children. In her 1977 book, Insights From the Blind, child psychoanalyst Selma Fraiberg described a girl named Kathie who had been blind since birth. Although bright and socially engaged, Kathie did not engage in imaginative play. And she tended to confuse the pronouns I and you, as well as other terms, such as here and there, come and go, and this and that. Such linguistic reversals, especially of pronouns, are common in young children with autism. Other autism-like behaviors often seen in blind children include repetitive movements, such as rocking back and forth; resistance to change; and echolalia, or repeating another persons words. Fraiberg termed such behaviors blindisms.
Some experts, including Michael Brambring, an emeritus psychologist at Bielefeld University in Germany, have argued that autism traits in blind children are just manifestations of blindness, not autism. What look like the same behaviors may sometimes stem from different prompts. As an example, one mother describes in an essay how her blind daughter would rock back and forth in a way that looked like an autism-like repetitive behavior until she realized her daughter was listening for squeaks in the floorboards. The girl had a different sensory world than a sighted person, and she was just exploring that.
This sort of misperception is widespread, says Pawan Sinha, a vision and autism expert and computational neuroscientist at the Massachusetts Institute of Technology. In 2005, Sinha founded an organization, staffed by surgeons, to restore sight in people with treatable causes of blindness in rural India. He says that many of the blind children he sees are shy at first, though sociable with familiar people. They also have some behaviors reminiscent of autism, such as echolalia. Having met with literally thousands of blind children, blind adults, I simply dont see the signs of high incidences of autism in that population, Sinha says. But he plans to look more closely by surveying autism characteristics in at least 1,000 blind adolescents in India.
Hobson and Jure maintain that autism traits should be seen as signs of autism even if they result from blindness. If you define the syndrome based on the behavior, [then] if you have the behavior, you have to call it autism too, Jure says. Whats more, automatically labeling autism-like behaviors blindisms could lead some clinicians to miss autism in blind children, he adds.
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Eyeing the connection between autism and vision - Spectrum