Abstract
Abstract: :
Purpose: Many patients with strabismus acquired following binocular vision maturation have abnormal stereoacuity despite successful eye re–alignment. In a prospective study, we examined predictive factors for stereoacuity outcomes in patients with acquired strabismus. Methods: Twenty–three patients 14–85 years of age with acquired strabismus were enrolled. Predictive factors studied were duration of constant eye misalignment, pre–surgical type of strabismus, pre–surgical diplopia, pre–surgical binocular vision capacity (stereopsis and sensory fusion with angle of strabismus neutralized with prisms), and post–surgical residual angle of deviation. Stereoacuity was measured using the Titmus circles test, the Randot Preschool Stereoacuity test and the Accommodata Distance Randot–style circles test. Results: Patients with <12 months constant eye misalignment achieved better stereoacuity (40, 60, 75 sec of arc on the Titmus circles, Randot Preschool and Distance Randot circles, respectively) than patients who had a constant eye misalignment >12 months (100, 400 sec, nil, P < .01). Patients with capacity for fine to moderate pre–surgical stereopsis achieved better stereoacuity (40, 80, 120 sec) than patients with no pre–surgical stereopsis capacity or who passed the Titmus fly only (140, 400 sec, nil, P < .01). Patients who passed the Worth 4–dot at 3 meters pre–operatively with prism correction achieved better stereoacuity (60, 120 sec) than those who had no sensory fusion at near (400 sec, nil) or at distance (400 sec, nil), as measured by the Randot Preschool test and the Distance Randotcircles, respectively. Patients with 4 pd or less post–surgical residual deviation (40, 100, 120 sec) or intermittent orthotropia (40, 100, 120 sec) achieved better stereoacuity than patients with 5–8 pd post–surgical residual deviation (250 sec, nil, nil, P < .05). Conclusions: Predictive factors of stereoacuity outcomes in patients with acquired strabismus include duration of constant eye misalignment and pre–surgical stereopsis and sensory fusion with angle of strabismus neutralized with prisms. Post–surgical residual deviation < 4 pd supports better stereoacuity outcomes. This finding does not support the traditional view that eye alignment within 10 pd of orthotropia supports binocularity.
Keywords: binocular vision/stereopsis • plasticity • strabismus: treatment