title: The role of central vision in posture: Postural sway adaptations in Stargardt patients.
abstract: The role of central and peripheral vision in the maintenance of upright stance is debated in literature. Stargardt disease causes visual deficits affecting the central field, but leaving unaltered a patient's peripheral vision. Hence, the study of this rare pathology gives the opportunity to selectively investigate the role of central vision in posture. Postural sway in quiet stance was analyzed in 10 Stargardt patients and 10 control subjects, in three different conditions: (1) eyes closed, (2) eyes open, gazing at a fixed target, and (3) eyes open, tracking a moving target. Stargardt patients outperformed controls in the condition with eyes closed, showing a reduced root mean square (RMS) of the medio-lateral COP displacement, while their performance was not significantly different from controls in the antero-posterior direction. There were no significant differences between patients and controls in open eyes conditions. These results suggest that Stargardt patients adapted to a different visual-somatosensory integration, relying less on vision, especially in the medio-lateral direction. Hence, the central vision seems to affect mostly the medio-lateral direction of postural sway. This finding supports the plausibility of the "functional sensitivity hypothesis", that assigns complementary roles to central and peripheral vision in the control of posture.
authors.affiliation: Dipartimento di Elettronica e Telecomunicazioni, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy. Electronic address: valentina.agostini@polito.it.
authors.forename: Valentina
authors.initials: V
authors.lastname: Agostini
authors.affiliation: Dipartimento di Elettronica e Telecomunicazioni, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy.
authors.forename: Agnese
authors.initials: A
authors.lastname: Sbrollini
authors.affiliation: Clinica C. Sperino, Ospedale Oftalmico di Torino, Via Juvarra 19, 10122 Torino, Italy.
authors.forename: Chanda
authors.initials: C
authors.lastname: Cavallini
authors.affiliation: Clinica C. Sperino, Ospedale Oftalmico di Torino, Via Juvarra 19, 10122 Torino, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Busso
authors.affiliation: Clinica C. Sperino, Ospedale Oftalmico di Torino, Via Juvarra 19, 10122 Torino, Italy.
authors.forename: Giulia
authors.initials: G
authors.lastname: Pignata
authors.affiliation: Dipartimento di Elettronica e Telecomunicazioni, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Knaflitz
mesh_terms: D000222:Adaptation, Physiological; D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D008268:Macular Degeneration / Q000151:congenital* / Q000503:physiopathology / Q000534:rehabilitation; D008297:Male; D011187:Posture / Q000502:physiology*; D000080362:Stargardt Disease; D014792:Visual Acuity; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult
keywords: Central vision; Postural sway; Posture; Stargardt; Visual impairment