JOHNSON CITY – For years, many doctors have believed that most children will develop crossed eyes, or esotropia, either at birth or during the first six months of life.
Now, a new study from East Tennessee State University's James H. Quillen College of Medicine suggests just the opposite.
In the April issue of Ophthalmology, the clinical journal of the American Academy of Ophthalmology, ETSU faculty member Dr. Brian Mohney reports on the results of a three-year study involving more than 220 children in which he found a higher incidence of esotropia among children older than six months.
According to Mohney, a number of physicians have long considered “congenital esotropia” to be the most common type of crossed eyes, followed by “accommodative esotropia.”
Congenital esotropia affects children at birth or within the first six months. These patients require surgery – often more than once – and typically do not have to wear glasses.
Those children with accommodative esotropia develop crossed eyes after the first six months of life. Approximately 60 percent of these patients can have the problem fully corrected by wearing glasses, Mohney explained. The other 40 percent will require both surgery and the use of glasses.
“There has never been a clear understanding of the epidemiology of childhood esotropia,” said Mohney, an associate professor of surgery at ETSU. “For example, many ophthalmologists believed that congenital esotropia was the most common. Furthermore, data on other forms of crossed eyes has been almost nonexistent.”
In the ETSU study, Mohney found that children with accommodative esotropia accounted for more than 50 percent of the cases and were diagnosed 10 times more frequently than those with the congenital condition, which accounted for only 5.4 percent of the patients.
“These findings are encouraging because children with accommodative esotropia have a much better prognosis and are less likely to require surgery,” he said.
Other types of esotropia, in addition to congenital and accommodative, were documented in the study.
One form, a condition known as “acquired nonaccommodative esotropia,” accounted for approximately 10 percent of the study cases. These children develop crossed eyes after the first six months but are candidates for surgery. Further, they do not have to wear glasses.
Mohney also found that one in every six children in the study with esotropia also had some type of central nervous system (CNS) disorder, such as cerebral palsy, autism, or Down syndrome.
Both the acquired nonaccommodative and CNS-related forms outnumbered the incidence of congenital esotropia.
“This study strongly suggests that esotropia is more likely to develop in children beyond the first six months of life,” Mohney said. “That is why pediatricians and ophthalmologists should remain especially diligent in examining children for crossed eyes during the first six years of life.
“The prognosis is extremely positive if we can examine and treat these children in time.”
For more information, contact Mohney at (423) 439-7215.