title: Alterations of posterior precortical vitreous pockets with positional changes.
abstract: OBJECTIVE
  To investigate the morphologic features of posterior precortical vitreous pockets (PPVPs) with positional changes using spectral domain optical coherence tomography.
  
  
  METHODS
  The authors measured the distance between the fovea and anterior PPVP border on spectral domain optical coherence tomography scans in both eyes of 20 consecutive individuals and compared the differences with changes in position from sitting to supine.
  
  
  RESULTS
  A PPVP was identified in both eyes of 14 individuals (70%). In the vertical scan, the superior portion of the pocket was larger than the inferior portion in all 28 eyes when the participants were sitting. The mean distances between the fovea and the anterior PPVPs that border in the right and left eyes, respectively, were 477.6 ± 40.7 μm and 497.1 ± 31.8 μm when the participants were sitting and 665.6 ± 51.6 μm and 750.5 ± 48.2 μm when the participants were supine. The differences between the 2 positions were significant (P < 0.005).
  
  
  CONCLUSIONS
  The superior portion of the PPVPs enlarged when the participants were sitting. The anterior border of the pocket moved anteriorly when the participants were supine.
authors.affiliation: Department of Ophthalmology, School of Medicine, Gunma University, Maebashi, Japan. itakurah@med.gunma-u.ac.jp
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Itakura
authors.forename: Shoji
authors.initials: S
authors.lastname: Kishi
mesh_terms: D000328:Adult; D000367:Age Factors; D005260:Female; D005584:Fovea Centralis / Q000033:anatomy & histology* / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D056888:Patient Positioning; D011187:Posture; D012029:Refraction, Ocular / Q000502:physiology; D016683:Supine Position; D041623:Tomography, Optical Coherence / Q000379:methods; D014822:Vitreous Body / Q000033:anatomy & histology* / Q000502:physiology