FRIDAY, June 12, 2009 (HealthDay News) -- Children who have a condition in which the eye sometimes points outward are more likely to develop a mental illness by young adulthood, new research has found.
About 1 percent of developmentally healthy U.S. children are diagnosed with intermittent exotropia, in which the eyes do not line up and one looks away from the nose at certain times.
Mayo Clinic researchers analyzed the medical records of 183 youths younger than 19 in Olmsted County, Minn., who were diagnosed with intermittent exotropia between 1975 and 1994.
The researchers matched each youth with another of the same age who did not have a diagnosis of any type of strabismus, in which the eyes are not properly aligned with each other. Both groups were followed to, on average, age 22.
Over the 20-year study period, 53 percent of the youths with intermittent exotropia were diagnosed with a mental health disorder, compared with 30 percent of the others.
Boys were especially at risk, according to the study, which is in the June issue of Archives of Ophthalmology.
The study found that, among children with intermittent exotropia, mental health disorders were diagnosed in 63 percent of the boys and 47 percent of the girls. By comparison, in the group without such eye problems, mental health disorders were diagnosed in 33 percent of the boys and 28 percent of the girls.
"Males with intermittent exotropia had a greater use of psychotropic medication, psychiatric emergency department visits, psychiatric hospital admissions, suicide attempts and suicidal ideation than controls, and females with intermittent exotropia had more suicidal ideation than controls," the study authors wrote.
However, the researchers noted, the reasons for the association between the eye condition and mental health issues are unclear.
Studies have found children with intermittent exotropia aren't judged more harshly by adults, but they can have a harder time with other children.
"A negative bias toward people with strabismus has been demonstrated in children," the researchers wrote. "Although this study focused on mental illness that was diagnosed by early adulthood, there is also evidence to suggest that the social problems associated with strabismus persist and even intensify into adult life."
They concluded that more study is needed "to determine whether interventions for intermittent exotropia can decrease or otherwise alter the future development of mental illness."
The American Association for Pediatric Ophthalmology and Strabismus has more on the condition and treatments.