Body mass index and binocular vision skills

Introduction: Body Mass Index (BMI) is of increasing interest to eye care practitioners. Associations have recently been proven between high BMI and several diseases affecting the eyes, including AMD, intracranial hypertension, optic disc cupping, and glaucoma.The symptoms of dizziness and vertigo have also been associated with high BMI. However, to these authors’ knowledge, there has been no study performed comparing BMI to binocular function. Methods: In this analytical-descriptive study, 119 randomly selected young subjects had their BMI measured, along with refractive error, dissociated phoria, near point of convergence, vergence ranges and facility, and stereopsis. Results: In most situations, the subjects classified as normal and overweight, based on their BMI had better performance than those classified as underweight or obese. The worst binocular performance was found in underweight subjects. The one-way ANOVA showed only statistically significant differences between mean of near point of convergence and vergence facility, in different states of BMI. Conclusion: Unlike most ocular diseases that are adversely affected by higher BMI values, most binocular vision skills are adversely affected by lower BMI values. The possible reasons for this are discussed.