title: Analysis of crystalline lens position.
abstract: OBJECTIVE
  To study normal crystalline lens position to provide a comparative baseline for future studies of crystalline lens or intraocular lens shift.
  
  
  METHODS
  Taipei Municipal Yang-Ming Hospital, Taipei, Taiwan.
  
  
  METHODS
  A Scheimpflug anterior segment analyzer (EAS-1000, Nidek) was prospectively applied to measure the cycloplegic crystalline lens position in subjects who had not had previous ocular surgeries or who had been diagnosed previously with major ocular diseases such as glaucoma, retinal detachment, or cataract. Measurements included anterior chamber depth (ACD), magnitudes, direction of lens decentration, and lens tilt. Refractive error was measured with an autorefractometer, and multiple linear regression was used to verify revealed relationships. The aging effect was determined with the Pearson correlation test.
  
  
  RESULTS
  Thirty-nine eyes of 30 subjects (15 men, median age 13 years, range 4 to 53 years) were included. The center of the anterior lens surface was decentered 0.25 mm superotemporally. The lens tilted 2.85 degrees with the anterior lens surface facing the inferotemporal quadrant. The mean ACD was 3.26 mm; it tended to increase before subjects reached 20 years of age and to decrease thereafter. With age, the lens tended to exhibit less tilt. Lens position did not affect the spherical equivalent or the magnitude of astigmatism.
  
  
  CONCLUSIONS
  The crystalline lens was not aligned perfectly along the visual axis, but its effect on refraction was limited.
authors.affiliation: Department of Ophthalmology, Far Eastern Memorial Hospital, Taipei Municipal Yang-Ming Hospital, Taipei, Taiwan. cyhu@med-assn.org.tw
authors.forename: Chao-Yu
authors.initials: CY
authors.lastname: Hu
authors.forename: Jeen-Hon
authors.initials: JH
authors.lastname: Jian
authors.forename: Yung-Piao
authors.initials: YP
authors.lastname: Cheng
authors.forename: Hsiang-Kai
authors.initials: HK
authors.lastname: Hsu
mesh_terms: D000293:Adolescent; D000328:Adult; D000869:Anterior Eye Segment / Q000033:anatomy & histology*; D002648:Child; D002675:Child, Preschool; D003941:Diagnostic Techniques, Ophthalmological; D005260:Female; D006801:Humans; D007908:Lens, Crystalline / Q000033:anatomy & histology* / Q000502:physiology; D008297:Male; D008875:Middle Aged; D009799:Ocular Physiological Phenomena; D011446:Prospective Studies; D012030:Refractive Errors / Q000175:diagnosis / Q000503:physiopathology