Binocular Vision and Stereopsis Following Delayed Strabismus Surgery

Purpose : Patients with infantile or childhood strabismus who do not achieve visual axes alignment early in life are believed to have poor prognosis with respect to the stereopsis. This study investigates the binocularity and stereopsis following delayed surgical alignment in patients with congenital and early-onset strabismus.Patients Methods : 36 patients aged between 6-30 years participated in this study. The inclusion criteria were: constant horizontal deviation of 30 prism diopters (PD) or more, strabismus onset before age 3 and surgical alignment after age 6 years, alignment to within 10 PD of orthotropia after surgery. All patients were examined comprehensively and four binocularity and stereopsis tests including Titmus, Random dot E, Bagolini lenses and Worth 4-dot test were performed for all.Results : Of 36 patients, 20 (55.5%) had binocular vision using Bagolini striated glasses, 14 (38.9%) with Titmus test, 12 (33.3%) with Worth 4-dot test and 8 (22.2%) with Random dot E test. The achievement of stereopsis after visual alignment was statistically significant (P=0.008). Of 14 patients with positive Titmus test, 8 (57.1%) had stereoacuity of 200 sec of arc or better.Conclusion : This study demonstrated that even after delayed alignment of eyes in patients with infantile or early childhood strabismus, some degrees of stereopsis can be achieved in most cases