The association between binocular vision and anisometropic amblyopia in children

Abstract

Introduction: Anisometropic amblyopia is the second most common cause of amblyopia in children population,  as a result of unequal refractive errors between the eyes. Eye with the greater refractive error has weaker binocular vision and signal from that eye is being suppressed. Aim: To evaluate the presence of binocular vision in children with anisometropic amblyopia before and after the treatment, then establish how is binocular vision affected by the magnitude of anisometropia, depth of amblyopia, pattern of fixation and type of refractive error. Patients and methods: Retrospective study was conducted in Pediatric Department of Clinic for Eye Disease of KCUS, in a period from 2016. to  2017. There were 100 patients with diagnosed anisometropic amblyopia. Results:. Anisometropia in average was 1,9±1,7D. During the first evaluation most of the patients didn't have stereopsis(62%), on the follow-ups 81% had stereopsis. Patients with intact binocular vision showed smallest differences in visual acuity 2,7±1,9, in anisometropia 1,2±0,9D also; statistically significant higher frequency of myopia and astigmatism with myopia, and foveolar fixation. Patient who developed binocular vision during the therapy had higher values of difference in visual acuity(4,4±2,7) and anisometropia 1,9±1,6D. Patients who haven't established binocular vision even after the therapy have the highest values in differences in visual acuity and anisometropia, 7,1±2,2 and 3,6±3,1D; highest frequency of hyperopia, eccentric fixation, and severity of amblyopia. Conclusion: Children with greater depth of amblyopia, higher magnitude  of anisometropia have less chance to achieve binocular vision.