To evaluate the postoperative changes of stereopsis after surgical correction of adult strabismus.

We retrospectively evaluated strabismus patients older than 16 years at the time of operation at our hospital between April of 1999 and December of 2006. We retrospectively examined the medical records of 53 exotropia and 11 esotropia patients. We divided the pre-operative stereopsis into three groups:above 3000 arc of sec, between 3,000 to 100 arc of sec, and below 100 arc of sec. We analyzed the correlation between the post-operative status of stereopsis and the pre-op type of strabismus, the onset and duration of strabismus, and the presence or absence of amblyopia.

In patients who had pre-op stereopsis above 3,000 arc of sec, 31.6% showed improvement, whereas 77.8% of patients who had pre-operative stereopsis between 3,000~100 showed improvement; this value was 89.5% for patients with pre-operative stereopsis below 3000. 94.5% of patients in the intermittent exotropia group who had a good pre-operative stereopsis condition showed postoperative improvement and maintenance. For those patients with poor stereopsis at pre-operative, 32.2% of patients with exotropia and 18.1% of patients with esotropia showed improvement. Stereopsis decreased when consecutive esotropia occurred.

This study showed deterioration of stereopsis in patients with consecutive esotropia. Post-operative stereopsis was correlated with the pre-operative stereopsis status and with the type of strabismus. No other factors that we examined were correlated with stereopsis. Post-operative stereopsis in exotropiaand intermittent exotropia were better than esotropia and constant exotropia.