title: Ocular higher-order aberrations in a school children population.
abstract: OBJECTIVE
  The primary objective of the study was to explore the statistics of ocular higher-order aberrations in a population of primary and secondary school children.
  
  
  METHODS
  A sample of 557 children aged 10-15 years were selected from two primary and two secondary schools in Heraklion, Greece. Children were classified by age in three subgroups: group I (10.7±0.5 years), group II (12.4±0.5 years) and group III (14.5±0.5 years). Ocular aberrations were measured using a wavefront aberrometer (COAS, AMO Wavefront Sciences, USA) at mesopic light levels (illuminance at cornea was 4lux). Wavefront analysis was achieved for a 5mm pupil. Statistical analysis was carried out for the right eye only.
  
  
  RESULTS
  The average coefficient of most high-order aberrations did not differ from zero with the exception of vertical (0.076μm) and horizontal (0.018μm) coma, oblique trefoil (-0.055μm) and spherical aberration (0.018μm). The most prominent change between the three groups was observed for the spherical aberration, which increased from 0.007μm (SE 0.005) in group I to 0.011μm (SE 0.004) in group II and 0.030μm (SE 0.004) in group III. Significant differences were also found for the oblique astigmatism and the third-order coma aberrations.
  
  
  CONCLUSIONS
  Differences in the low levels of ocular spherical aberration in young children possibly reflect differences in lenticular spherical aberration and relate to the gradient refractive index of the lens. The evaluation of spherical aberration at certain stages of eye growth may help to better understand the underlying mechanisms of myopia development.
authors.affiliation: Institute of Vision and Optics (IVO), University of Crete, Greece.
authors.forename: George
authors.initials: G
authors.lastname: Papamastorakis
authors.affiliation: Institute of Vision and Optics (IVO), University of Crete, Greece.
authors.forename: Sophia
authors.initials: S
authors.lastname: Panagopoulou
authors.affiliation: Institute of Vision and Optics (IVO), University of Crete, Greece; Department of Ophthalmology, University Hospital of Crete, Greece.
authors.forename: Militadis K
authors.initials: MK
authors.lastname: Tsilimbaris
authors.affiliation: Institute of Vision and Optics (IVO), University of Crete, Greece; Department of Ophthalmology, University Hospital of Crete, Greece.
authors.forename: Ioannis G
authors.initials: IG
authors.lastname: Pallikaris
authors.affiliation: Institute of Vision and Optics (IVO), University of Crete, Greece; Faculty of Life Sciences, University of Manchester, Manchester, UK. Electronic address: plainis@med.uoc.gr.
authors.forename: Sotiris
authors.initials: S
authors.lastname: Plainis
mesh_terms: D000293:Adolescent; D000704:Analysis of Variance; D001251:Astigmatism / Q000209:etiology / Q000473:pathology; D002648:Child; D057108:Corneal Wavefront Aberration / Q000473:pathology* / Q000503:physiopathology; D005260:Female; D006115:Greece; D006801:Humans; D008297:Male; D009216:Myopia / Q000209:etiology / Q000473:pathology; D012029:Refraction, Ocular / Q000502:physiology; D012030:Refractive Errors / Q000209:etiology / Q000473:pathology*
keywords: Aberraciones oculares; Aberración esférica; Children; Niños; Ocular aberrations; Spherical aberration