title: The Impact of Lens Vault on Visual Acuity and Refractive Error: Implications for Management of Primary Angle-closure Glaucoma.
abstract: OBJECTIVE
  To investigate the relationship between lens vault (LV), visual acuity (VA), and refraction.
  
  
  METHODS
  This was a cross-sectional study of 2047 subjects aged 50 years and older recruited from a community polyclinic. Anterior segment optical coherence tomography was performed, and customized software was used to measure LV. VA was measured using a logarithm of minimum angle of resolution chart (logMAR chart; Lighthouse Inc.), and was classified as normal (logMAR<0.3), mild impairment (0.3<logMAR<0.6), and moderate/severe impairment (logMAR>0.6). Refraction was measured with an autorefractor machine and spherical equivalent was defined as sphere plus half cylinder. Angle closure was defined as posterior trabecular meshwork not visible for ≥2 quadrants on nonindentation gonioscopy.
  
  
  RESULTS
  Complete data were available for 1372 subjects including 295 (21.5%) with angle closure. Angle-closure subjects were significantly older (P<0.001), with shorter axial length (P<0.001), shallower anterior chamber depth (P<0.001), and greater LV (P<0.001). There was no significant difference in VA (P=0.12) compared with those without angle closure. After adjusting for age, sex, axial length, anterior chamber depth, and spherical equivalent, there was no significant association between LV and VA (P=0.35) or between LV and spherical equivalent (P=0.06).
  
  
  CONCLUSIONS
  The magnitude of LV was not associated with VA or spherical equivalent. Lens extraction may be a consideration in eyes with angle closure with large LV in the absence of visually significant cataract.
authors.affiliation: *Singapore National Eye Centre, Singapore Eye Research Institute †Duke-NUS Graduate Medical School §Yong Loo Lin School of Medicine, National University of Singapore, Singapore ‡University College London Medical School, London, UK.
authors.forename: Monisha E
authors.initials: ME
authors.lastname: Nongpiur
authors.forename: Shweta
authors.initials: S
authors.lastname: Singhal
authors.forename: Stephen
authors.initials: S
authors.lastname: Stewart
authors.forename: Hla M
authors.initials: HM
authors.lastname: Htoon
authors.forename: Arun K
authors.initials: AK
authors.lastname: Narayanaswamy
authors.forename: Tien Y
authors.initials: TY
authors.lastname: Wong
authors.forename: Shamira A
authors.initials: SA
authors.lastname: Perera
authors.forename: Tin
authors.initials: T
authors.lastname: Aung
mesh_terms: D000368:Aged; D003430:Cross-Sectional Studies; D005260:Female; D015812:Glaucoma, Angle-Closure / Q000503:physiopathology* / Q000601:surgery*; D006068:Gonioscopy; D006801:Humans; D007429:Intraocular Pressure; D032801:Iridectomy; D007498:Iris / Q000601:surgery; D007905:Lens Diseases / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D012029:Refraction, Ocular / Q000502:physiology; D012030:Refractive Errors / Q000503:physiopathology*; D041623:Tomography, Optical Coherence / Q000379:methods; D014792:Visual Acuity / Q000502:physiology*