Study Links Poor Motor Function, Increased Strabismus Risk in CP

A new study reports that cerebral palsy patients with poorer motor function abilities are more likely to have strabismus.

The study, “Strabismus is correlated with gross motor function in children with spastic cerebral palsy,” was published in the journal Current Eye Research.

Strabismus is when a person’s eyes don’t look at exactly the same spot — one eye might be focused straight ahead, while the other is pointing slightly to one side or another. This condition is estimated to affect somewhere between half and three-quarters of people with cerebral palsy.

A team of South Korean researchers wondered whether particular aspects of how cerebral palsy manifests — such as differences in motor abilities — might predict whether a given patient is more or less likely to have strabismus.

Researchers examined the medical records of patients who had been diagnosed with spastic cerebral palsy and had an eye doctor appointment as part of a routine check-up between 2006 and 2014 at the Department of Ophthalmology, Pusan National University Hospital, South Korea.

Sixty-two patients’ records were identified. They were classified as having either mild (38 people) or severe (24 people) motor impairment, based largely on whether they were able to walk under their own power (with or without an assisting device).

They were also classified based on how motor impairment was distributed: on just one side of the body (hemiplegia, four people), on both sides (diaplegia, 42 people), or in all four limbs (quadriplegia, 16 people).

The researchers then analyzed these and other patient characteristics to see which, if any, were related to the likelihood of having strabismus, which was identified in 40 of the patients.

Cerebral palsy patients with more severe motor impairment — assessed using the Gross Motor Function Classification System (GMFCS) — were significantly more likely to have strabismus, which affected 52.6% and 83.3% of patients classified as having mild and severe motor impairment, respectively.

The researchers did not find any significant association between strabismus risk and different cerebral palsy subtypes (i.e. hemiplegia, diaplegia, and quadriplegia). Other factors, such as birth weight and gestational age (the time between conception and birth), were also found to have no association with strabismus risk.

“We expect that this study will provide a better understanding of strabismus in [cerebral palsy] patients and may help to elucidate the pathogenesis of strabismus,” the researchers stated.

Of note, this is a relatively small, retrospective study looking at patients at a single hospital. Further research will be needed to better understand the relationship between strabismus and cerebral palsy.