title: Real-Time Measurement of Dynamic Changes of Anterior Segment Biometry and Wavefront Aberrations During Accommodation.
abstract: OBJECTIVE
  To analyze the dynamic relationship between ocular geometrical structure and high-order aberrations (HOAs) in teal-time during accommodation of human eye.
  
  
  METHODS
  A custom-built spectral domain optical coherence tomography (OCT) system with high-speed and ultra-long scan depth was used to image the anterior segment, whereas a Shack-Hartmann wavefront sensor was used to detect the whole-eye aberration. A Badal optometer with switched visual targets was integrated with this system to induce 0 and 3.00 D accommodative stimuli. Three young adult subjects were measured and the structural parameters of anterior segment were measured from OCT images and accommodative response and HOAs were calculated and exponentially fitted in real time during the accommodation.
  
  
  RESULTS
  The dynamic process from nonaccommodation to 3.00 D accommodation results in reduced pupil diameter, shallower anterior chamber depth, and increased crystalline lens thickness. After an accommodative active time, the RMS of the HOAs changes sharply when an accommodative stimulus is introduced and then tends to be stable. The accommodative response time and velocity are characterized by fitted parameters. The individual differences of changing in HOAs between subjects can be explained by the different sign and changing tendency of certain terms of aberration coefficients in form of Zernike polynomials during the accommodation.
  
  
  CONCLUSIONS
  Based on the integrated ocular measurement platform including OCT system and wavefront sensor, our research demonstrated how the morphology of the human anterior segment affect the aberration in real time during accommodation. The dynamic relationship between them helps us to deeply understand the mechanism of accommodation.
authors.affiliation: School of Ophthalmology and Optometry (D.Z., Y.S., Y.P., Q.C., F.L., M.S.), Wenzhou Medical University, Wenzhou, China; and Department of Ophthalmology (J.W.), Bascom Palmer Eye Institute, University of Miami, Miami, FL.
authors.forename: Dexi
authors.initials: D
authors.lastname: Zhu
authors.forename: Yilei
authors.initials: Y
authors.lastname: Shao
authors.forename: Yu
authors.initials: Y
authors.lastname: Peng
authors.forename: Qi
authors.initials: Q
authors.lastname: Chen
authors.forename: Jianhua
authors.initials: J
authors.lastname: Wang
authors.forename: Fan
authors.initials: F
authors.lastname: Lu
authors.forename: Meixiao
authors.initials: M
authors.lastname: Shen
mesh_terms: D000065:Accommodation, Ocular / Q000502:physiology*; D000328:Adult; D000869:Anterior Eye Segment / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D001699:Biometry / Q000379:methods; D057108:Corneal Wavefront Aberration / Q000473:pathology*; D058453:Emmetropia / Q000502:physiology; D005260:Female; D006801:Humans; D007908:Lens, Crystalline / Q000033:anatomy & histology / Q000502:physiology*; D008297:Male; D012029:Refraction, Ocular / Q000502:physiology; D041623:Tomography, Optical Coherence / Q000379:methods