Assessment of control in intermittent exotropia

In the context of intermittent exotropia, the term "control" is used to refer to the proportion of the time the eyes are manifestly exotropic and the time to recovery of fusion after the eyes have been dissociated. In the past, the degree of control has been used to determine whether and when to perform surgery. Control has been assessed in a variety of ways; parental report, office assessment, and combined scales. Using a new office scale, variability of control was assessed during the course of a single day, and found to be highly variable in about half of children with IXT. We need more complete data before we can use control to guide surgical decision making. Currently, a conservative approach might be most reasonable, reserving surgery for children who show deterioration of near motor fusion, deterioration of near stereoacuity, emergence of clear symptoms or social concerns. Future studies of natural history, outcomes, and randomized clinical trials are needed to develop truly evidence-based management strategies.