Majallah-i Dānishgāh-i ̒Ulūm-i Pizishkī-i Bābul (Dec 2008)
EVALUATION OF NEAR BINOCULAR VISION IN SYMPTOMATIC AND ASSYMPTOMATIC MICROSCOPISTS
Abstract
BACKGROUND AND OBJECTIVE: According to high prevalence of near binocular vision anomalies in people who have long term near work and necessity to treatment of these anomalies for increasing of efficiency, the purpose of this study was to evaluate near binocular vision in symptomatic and asymptomatic microscopists.METHODS: In this cross-sectional study, 50 subjects of microscopists of Zahedan Medical University participated. These subjects divided into symptomatic and asymptomatic groups according to presence or absence of binocular vision problems. After determination of refractive errors with retinoscopy, if subject had inclusion criteria, referred to optometry department. Near point of convergence, positive and negative fusional vergence, near heterophoria and accommodation convergence/accommodation (AC/A) ratio were determined by use of millimeter ruler, prism bar, alternate prism cover test and gradient method, respectively. Stereopsis was measured by using TNO. The data was analyzed using independent sample t test.FINDINGS: In this study near point of convergence, near heterophoria, positive and negative fusional vergence and stereopsis had significant difference between symptomatic and asymptomatic groups (p<0.05) but there was not statistically significant difference between symptoms and AC/A ratio. CONCLUSION: In this study maximum difference between symptomatic and asymptomatic groups was related to positive fusional convergence and minimum difference was related to AC/A ratio. Hence, near point of convergence, positive and negative fusional vergence, near heterophoria and stereopsis are good indicators for binocular vision evaluation but AC/A ratio is not.
