Control of intermittent exotropia found to vary throughout the day

The authors of this study investigated the presence and degree of change of control of an exotropic deviation throughout the course of a day. Twenty-five patients with intermittent exotropia were studied. The "control" score was based upon the proportion of time the deviation was manifest and the ease of re-establishing fusion after dissociation. This control measure is believed by some ophthalmologists to be a factor in deciding if a patient requires surgical correction of the exotropia.

The investigators found that control of the exotropic deviation varied throughout the day, even between minutes, including from phoric to tropic and vice versa. The authors concluded that an isolated assessment of control may not accurately categorize severity of intermittent exotropia in an individual patient.

This study confirmed the commonly recognized phenomenon of intraday variability of control of intermittent exotropia. The role that this measure of control should play in deciding whether a patient requires surgery remains to be determined.