Boys With Intermittent Eye Deviation Appear More Likely To Develop Mental Illness

"Intermittent exotropia occurs in approximately 1 percent of developmentally healthy children in the United States and, given its predominance over esodeviations [when the eye turns in] among Asian populations, it may be the most prevalent form of strabismus worldwide," the authors write as background information in the article.

Jeff A. McKenzie, B.A., and colleagues at Mayo Clinic, Rochester, Minn., analyzed the medical records of 183 children younger than 19 in Olmsted County, Minn., who were diagnosed with intermittent exotropia between 1975 and 1994. For each patient, the researchers identified one control child who was the same age but did not have a diagnosis of any type of strabismus. Both groups were followed to an average age of 22.

During the 20-year study period, 97 of the children with intermittent exotropia (53 percent) were diagnosed with a mental health disorder, compared with 55 controls (30.1 percent)—meaning that patients with the condition had an increased risk of developing a psychiatric illness. Mental health disorders were diagnosed in 63 percent of boys (41 of 65) and 47 percent of girls (56 of 118) with intermittent exotropia, compared with 33 percent of boys (22 of 66) and 28 percent of girls (33 of 117) in the control group.

"Additionally, 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 authors write.

The reasons underlying these associations remain unclear, the authors note. "Studies regarding the psychosocial impact of strabismus have reported that individuals with intermittent exotropia are not judged more poorly than individuals with orthotropia [the absence of strabismus] by adult observers. However, a negative bias toward people with strabismus has been demonstrated in children," the authors write. "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."

"Further study is needed to determine whether interventions for intermittent exotropia can decrease or otherwise alter the future development of mental illness," they conclude.

This study was supported in part by an unrestricted grant from Research to Prevent Blindness Inc., New York, New York.