title: Age- and stereovision-dependent eye-hand coordination deficits in children with amblyopia and abnormal binocularity.
abstract: OBJECTIVE
  To examine factors contributing to eye-hand coordination deficits in children with amblyopia and impaired stereovision.
  
  
  METHODS
  Participants were 55 anisometropic or strabismic children aged 5.0 to 9.25 years with different degrees of amblyopia and abnormal binocularity, along with 28 age-matched visually-normal controls. Pilot data were obtained from four additional patients studied longitudinally at different treatment stages. Movements of the preferred hand were recorded using a 3D motion-capture system while subjects reached-to-precision grasp objects (two sizes, three locations) under binocular, dominant eye, and amblyopic/nonsighting eye conditions. Kinematic and "error" performance measures were quantified and compared by viewing condition and subject group using ANOVA, stepwise regression, and correlation analyses.
  
  
  RESULTS
  Movements of the younger amblyopes (age 5-6 years; n = 30) were much slower, particularly in the final approach to the objects, and contained more spatial errors in reaching (∼×1.25-1.75) and grasping (∼×1.75-2.25) under all three views (P < 0.05) than their age-matched controls (n = 13). Amblyopia severity was the main contributor to their slower movements with absent stereovision a secondary factor and the unique determinant of their increased error-rates. Older amblyopes (age 7-9 years; n = 25) spent longer contacting the objects before lifting them (P = 0.015) compared with their matched controls (n = 15), with absence of stereovision still solely related to increases in reach and grasp errors, although these occurred less frequently than in younger patients. Pilot prospective data supported these findings by showing positive treatment-related associations between improved stereovision and reach-to-grasp performance.
  
  
  CONCLUSIONS
  Strategies that children with amblyopia and abnormal binocularity use for reach-to-precision grasping change with age, from emphasis on visual feedback during the "in-flight" approach at ages 5 to 6 years to more reliance on tactile/kinesthetic feedback from object contact at ages 7 to 9 years. However, recovery of binocularity confers increasing benefits for eye-hand coordination speed and accuracy with age, and is a better predictor of these fundamental performance measures than the degree of visual acuity loss.
authors.affiliation: Division of Optometry & Visual Science, City University London, London, United Kingdom.
authors.forename: Simon
authors.initials: S
authors.lastname: Grant
authors.affiliation: Division of Optometry & Visual Science, City University London, London, United Kingdom.
authors.forename: Catherine
authors.initials: C
authors.lastname: Suttle
authors.affiliation: Division of Optometry & Visual Science, City University London, London, United Kingdom.
authors.forename: Dean R
authors.initials: DR
authors.lastname: Melmoth
authors.affiliation: Division of Optometry & Visual Science, City University London, London, United Kingdom.
authors.forename: Miriam L
authors.initials: ML
authors.lastname: Conway
authors.affiliation: Moorfields Eye Hospital, London, United Kingdom.
authors.forename: John J
authors.initials: JJ
authors.lastname: Sloper
mesh_terms: D000367:Age Factors; D000375:Aging / Q000502:physiology*; D000550:Amblyopia / Q000503:physiopathology*; D000704:Analysis of Variance; D015858:Anisometropia / Q000503:physiopathology; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005133:Eye Movements / Q000502:physiology*; D005260:Female; D006225:Hand / Q000502:physiology*; D006801:Humans; D008297:Male; D010865:Pilot Projects; D011597:Psychomotor Performance / Q000502:physiology*; D013285:Strabismus / Q000503:physiopathology; D013647:Task Performance and Analysis; D015348:Vision, Binocular / Q000502:physiology*
keywords: grasping; reaching; visuomotor control
references.citation: Invest Ophthalmol Vis Sci. 2012 Feb 21;53(2):817-24
references.pmid: 22169103
references.citation: PLoS One. 2013;8(1):e54230
references.pmid: 23382882
references.citation: Exp Brain Res. 2004 Aug;157(3):383-90
references.pmid: 15221161
references.citation: Vision Res. 1981;21(7):1065-74
references.pmid: 7314487
references.citation: Optom Vis Sci. 2010 Sep;87(9):697-704
references.pmid: 20622704
references.citation: Br J Ophthalmol. 2004 Dec;88(12):1552-6
references.pmid: 15548811
references.citation: J Vis. 2003;3(5):380-405
references.pmid: 12875634
references.citation: Invest Ophthalmol Vis Sci. 2013 Dec 17;54(13):8204-13
references.pmid: 24222309
references.citation: Q J Exp Psychol A. 2004 Feb;57(2):269-96
references.pmid: 14742177
references.citation: Perception. 1977;6(2):139-44
references.pmid: 876815
references.citation: Exp Brain Res. 2007 Nov;183(3):283-98
references.pmid: 17665181
references.citation: Vision Res. 1994 Mar;34(5):689-707
references.pmid: 8160386
references.citation: Invest Ophthalmol Vis Sci. 2014 May 27;55(6):3857-65
references.pmid: 24867577
references.citation: Exp Brain Res. 2007 Jun;179(4):723-6
references.pmid: 17487478
references.citation: Exp Brain Res. 2012 Jan;216(1):71-80
references.pmid: 22038720
references.citation: Ophthalmology. 2006 Jun;113(6):904-12
references.pmid: 16751033
references.citation: J Neurosci. 2008 Apr 30;28(18):4726-35
references.pmid: 18448649
references.citation: Nature. 1998 Aug 20;394(6695):780-4
references.pmid: 9723616
references.citation: Strabismus. 2011 Sep;19(3):119-28
references.pmid: 21870915
references.citation: BMJ Case Rep. 2011 Feb 23;2011:
references.pmid: 22707543
references.citation: Strabismus. 2011 Sep;19(3):110-8
references.pmid: 21870914
references.citation: Br J Ophthalmol. 2006 Jul;90(7):836-8
references.pmid: 16540485
references.citation: Invest Ophthalmol Vis Sci. 2010 May;51(5):2487-95
references.pmid: 20335609
references.citation: Invest Ophthalmol Vis Sci. 2011 Mar 01;52(3):1851-64
references.pmid: 21212188
references.citation: Ophthalmology. 2003 Nov;110(11):2088-92
references.pmid: 14597513
references.citation: J Exp Child Psychol. 1984 Oct;38(2):208-19
references.pmid: 6491596
references.citation: J AAPOS. 2009 Aug;13(4):350-3, 353.e1-2
references.pmid: 19683186
references.citation: Clin Exp Ophthalmol. 2013 Mar;41(2):127-34
references.pmid: 22712767
references.citation: J AAPOS. 2013 Apr;17(2):166-73
references.pmid: 23622448
references.citation: J Exp Child Psychol. 1984 Aug;38(1):19-32
references.pmid: 6470618
references.citation: Invest Ophthalmol Vis Sci. 2004 Sep;45(9):3048-54
references.pmid: 15326120
references.citation: J Neurophysiol. 2008 Nov;100(5):2627-39
references.pmid: 18768646
references.citation: Invest Ophthalmol Vis Sci. 2009 Aug;50(8):3711-20
references.pmid: 19339741
references.citation: Exp Brain Res. 2006 May;171(3):371-88
references.pmid: 16323004
references.citation: J Exp Psychol. 1954 Jun;47(6):381-91
references.pmid: 13174710
references.citation: Neuropsychologia. 1971 Mar;9(1):97-113
references.pmid: 5146491
references.citation: PLoS Biol. 2011 Aug;9(8):e1001135
references.pmid: 21912514
references.citation: Invest Ophthalmol Vis Sci. 2007 Mar;48(3):1139-48
references.pmid: 17325157
references.citation: PLoS One. 2012;7(2):e31075
references.pmid: 22363549
references.citation: Invest Ophthalmol Vis Sci. 2011 Feb 09;52(2):795-803
references.pmid: 21051723
references.citation: Invest Ophthalmol Vis Sci. 2010 Apr;51(4):2019-23
references.pmid: 19933184
references.citation: Exp Brain Res. 2004 Oct;158(3):317-27
references.pmid: 15164152
references.citation: Invest Ophthalmol Vis Sci. 2003 Apr;44(4):1555-67
references.pmid: 12657592
references.citation: Neuropsychologia. 2000;38(11):1473-81
references.pmid: 10906373
references.citation: Motor Control. 1999 Jul;3(3):237-71
references.pmid: 10409797
references.citation: J Mot Behav. 1979 Sep;11(3):189-200
references.pmid: 23962287
references.citation: J Neurosci. 2009 Jan 21;29(3):727-42
references.pmid: 19158299
references.citation: Vision Res. 2005 Jul;45(15):1975-89
references.pmid: 15820516
references.citation: Neuropsychologia. 2003;41(4):415-20
references.pmid: 12559159
references.citation: Invest Ophthalmol Vis Sci. 1999 Nov;40(12):2859-71
references.pmid: 10549646
references.citation: Vision Res. 2006 Aug;46(16):2571-80
references.pmid: 16530244
references.citation: Ophthalmic Physiol Opt. 2008 Sep;28(5):422-8
references.pmid: 18761479
references.citation: Exp Brain Res. 2012 Oct;222(3):265-76
references.pmid: 22899313
references.citation: J Cogn Neurosci. 2001 Jan 1;13(1):8-17
references.pmid: 11224905
references.citation: Proc Natl Acad Sci U S A. 2011 Sep 13;108(37):E733-41
references.pmid: 21896742
references.citation: J Neurosci. 2009 Feb 11;29(6):1688-98
references.pmid: 19211876
references.citation: Vision Res. 2011 Jul 1;51(13):1567-87
references.pmid: 20691202