Purpose: To evaluate the factors affecting improvement of stereopsis following successful surgical correction of childhood strabismus in adults.
Methods: In a prospective study, consecutive patients with childhood-onset, comitant, horizontal, constant strabismus; stereoacuity of more than 480 seconds of arc in TNO stereo test (absent stereopsis in TNO); and who had successful postoperative alignment (within 10 prism diopters [PD] of orthotropia) were enrolled. Postoperative stereopsis testing was performed using the TNO stereo test at 3 months after surgery.
Results: A total of 34 patients (20 exotropes and 14 esotropes) were included. The mean age at the time of surgery was 26.08±10.53 years (range, 14-53 years). Stereopsis was improved in 8 of 34 patients (23.5%). Postoperative alignment had influence on improvement of stereopsis; 38.1% of patients who had orthotropia gained stereopsis, whereas none of patients who had horizontal heterotropia (esotropia or exotropia) of 10 PD or less gained stereopsis (p=0.01). Misalignment of 10 years' duration or longer did not preclude the development of postoperative stereoacuity (p=0.31). There was a statistically insignificant increase in improvement of stereopsis in nonamblyopic group (30.4%) compared with amblyopic group (9.1%) (p=0.22). Also, there was a statistically insignificant increase in improvement of stereopsis in exotropes (35%) compared with esotropes (7.1%) (p=0.1). The angle of preoperative deviation had no influence on improvement of stereopsis (p=0.44).
Conclusion: A postoperative correction of orthotropia was the only predictive factor for improvement of stereopsis in adults with childhood strabismus.
Keywords: Stereopsis; strabismus; surgical correction.