Prevalence and risk factors of near decompensated heterophoria in a population of university students

Purpose The aim of this study was to determine the prevalence and risk factors of near decompensated heterophoria in a population of university students. Methods In a randomized study, 406 students of six schools of Mashhad University of Medical Sciences were selected and classified into symptomatic and non symptomatic groups. Visual acuity (VA), near point of convergence (NPC), Near point of accommodation (NPA), dissociated and associated phoria, suppression, stereopsis, accommodative facility, relative accommodation, accommodative convergence/accommodation ( AC/A ratio and fusional reserves were measured in two groups. The data were analysed by using SPSS software, version 11.5o. Results The prevalence of symptoms and binocular disorders in students were 41.6% and 21.8% respectively . Of the students,9.1% had near decompensated heterophoria (heterophoria with symptoms). The results of this study showed that VA, NPC, NPA, heterophoria, stereopsis, accommodative facility, relative accommodation, AC/A ratio and fusional reserves were different in symptomatic and asymptomatic subjects and were worsen in students with decompensated heterophoria (P<0.05). Conclusion The results of this study indicated relatively high prevalence of symptomatic students, binocular dysfunction and decompensated heterophoria in university students. Students with decompensated heterophoria failed in more visual skills which can be risk factors for decompensating the heterophoria.