In what age should we operate on children with primary exotropia? Indications based on own therapeutic results

Introduction
The aim of the study was to evaluate the results of surgical treatment of children with primary exotropia, operated on before 14 years of age.

Material and methods
The study included 62 children with primary, constant and intermittent exotropia operated on before 14 years of age. The patients were divided into two age groups. The first one consisted of children 2 to 6 years old (mean 4.75 ± 1.12) – 12 girls and 8 boys, the second group consisted of children 7 to 14 years old (mean 9.3 ± 2.1) – 30 girls and 12 boys. Follow-up period was 3.5 years in group I and 4.5 years in group II. History, visual acuity and refraction were obtained in all cases. Horizontal and vertical angles for distance and near, before and after the surgery was measured as well. The postoperative horizontal angle drift was estimated in both groups and function of binocular vision assessed, before and after the surgery.

Results
In both age groups we found no statistical difference between mean angle values before and few weeks after the surgery. However in long-term results, angle for distance was lower in younger children, especially in those with intermittent strabismus. The postoperative angle drift was lower in younger group with intermittent strabismus comparing to the older group, so they achieved a better final surgical outcome. The functional results in both age groups did not differ significantly.

Conclusions
Early surgery on divergent strabismus makes the prognosis better, especially in intermittent strabismus. Children that are operated on early, seem to have smaller postoperative angle drift.