Children who are four and younger may have better surgical outcomes for intermittent exotropia than older pediatric patients, a study in The American Journal of Ophthalmology suggests. A team of US researchers found 50% of kids aged five to 10 had poor surgical outcomes by three years compared with only 28% of children between the ages of three and four.

The study was a secondary analysis of pooled data from a randomized trial where 197 children aged three to 10 with basic-type intermittent exotropia of 15 to 40 prism diopters were randomly assigned to one of two surgical procedures for treatment. In the original trial, masked examinations were conducted every six months for three years. Suboptimal surgical outcome was defined as constant or intermittent exotropia of 10 or more diopters at distance or near; constant esotropia of six or more diopters at distance or near; a decrease in near stereoacuity of more than two octaves at any masked examination; or an additional operation without meeting any of the criteria.

The suboptimal surgical outcome by three years was 28% (19 out of 72) for children aged three to four and 50% (57 of 125) for children five to 10. The researchers didn’t observe any substantial links between poor surgical outcomes and other baseline factors such as magnitude of deviation, control score, fixation preference or near stereoacuity.

The study noted the need for further investigations that compare immediate to delayed surgery in these pediatric populations.