title: The relationship between binocular vision symptoms and near point of convergence.
abstract: OBJECTIVE
  Due to the relatively high prevalence of binocular vision anomalies, a regular examination including tests for assessment and determination of these anomalies is necessary. The aim of this study was to assess the relationship between near point of convergence (NPC) and near binocular vision symptoms and finding of an NPC cutoff point for symptoms in university students.
  
  
  METHODS
  In this cross-sectional study, 124 students of different majors of Zahedan University of Medical Sciences were randomly selected. If they met the inclusion criteria, they were divided into two groups (symptomatic and asymptomatic) according to the convergence insufficiency symptom survey questionnaire. For NPC measurement, a small isolated letter "E" of approximately 20/30 size on a metal rod was used. After data collection, data were analyzed in SPSS.17 software (SPSS for Windows, SPSS Inc., Chicago, IL) using descriptive and analytical statistics, including Mann-Whitney U test and receiver operating characteristic (ROC) curve.
  
  
  RESULTS
  The mean NPC findings in the symptomatic and asymptomatic groups were 11.7 ± 5.0 and 8.4 ± 3.4 cm, respectively, with a significant difference between the two groups (P < 0.001). The ROC curve suggests an NPC cutoff point of 9.5 cm for the presence of symptoms with the testing procedures used in this study. Conclusion : The determination of NPC is helpful in the differentiation of symptomatic from asymptomatic subjects.
authors.affiliation: Department of Optometry, School of Rehabilitation Sciences, Health Promotion Research Center, Zahedan University of Medical Sciences, Zahedan, Iran.
authors.forename: Momeni-Moghaddam
authors.initials: MM
authors.lastname: Hamed
authors.forename: A Goss
authors.initials: AG
authors.lastname: David
authors.forename: Ehsani
authors.initials: E
authors.lastname: Marzieh
mesh_terms: D000065:Accommodation, Ocular; D003290:Convergence, Ocular / Q000502:physiology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D015835:Ocular Motility Disorders / Q000175:diagnosis* / Q000503:physiopathology; D012016:Reference Values; D014787:Vision Tests / Q000379:methods; D015348:Vision, Binocular / Q000502:physiology*; D014792:Visual Acuity; D055815:Young Adult
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