Background: Intermittent exotropia, X(T), is a relatively common form of strabismus among children in Singapore. The purpose of this study is to see how children presenting with this condition fared during a period of 5 years.
Methods: The medical records of all children younger than 16 years who presented to the eye clinic at the Singapore National Eye Centre with X(T) between January 1992 and December 1995 were reviewed retrospectively.
Results: A total of 287 patients satisfied the entry requirements of this study. Estimated age of onset of exotropia was documented in 161 subjects. The mean age of estimated onset was 3.0 +/- 2.5 years. The mean age of presentation was 6.1 +/- 3.1 years. The mean amount of distant exotropia was 36.4 +/- 12.5 prism diopters (PD). Seventy-two percent of children had poor/no distant control. During a 3-year period, the size of exotropia appears to remain constant (within 5 PD of original) in 48% and improved >5 PD in 32%. Control of distant exotropia remained the same in 63%, improved in 17% and worsened in 20%. Near exotropia was initially present in only 35.5%. The mean amount of near exotropia, when present, was 25.9 +/- 13.7PD. Near control remained the same in 65% and worsened in 22%. More variation was observed in subjects presenting before 5 years of age. One hundred sixty-two (56.4%) subjects underwent surgery. The mean age of surgery was 8.0 +/- 2.6 years. Surgery resulted in a final strabismus size between 10 PD exotropia and 5PD esotropia in 65.2% at 1 year postoperation.
Conclusion: Half the subjects presenting with an intermittent exotropia eventually had surgery. In the remaining nonsurgical subjects, intermittent exotropia, once present, appeared to be a relatively stable condition.