title: Sources of variance in ocular microtremor.
abstract: This study presents a preliminary investigation of the sources of variance in the measurement of ocular microtremor frequency in a normal population. When the results from both experienced and relatively inexperienced operators are pooled, factors that contribute significantly to the total variance include the measurement procedure (p < 0.001), day-to-day variations within subjects (p < 0.001), and inter-subject differences (p < 0.01). Operator experience plays a role in determining the measurement precision: the intra-subject coefficient of variation is about 5% for a very experienced operator, and about 14% for a relatively inexperienced operator.
authors.affiliation: Mercer's Institute for Research in Ageing, St James's Hospital, Dublin, Ireland.
authors.forename: N F
authors.initials: NF
authors.lastname: Sheahan
authors.forename: D
authors.initials: D
authors.lastname: Coakley
authors.forename: C
authors.initials: C
authors.lastname: Bolger
authors.forename: D
authors.initials: D
authors.lastname: O'Neill
authors.forename: G
authors.initials: G
authors.lastname: Fry
authors.forename: J
authors.initials: J
authors.lastname: Phillips
authors.forename: J F
authors.initials: JF
authors.lastname: Malone
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D005133:Eye Movements / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D014202:Tremor / Q000453:epidemiology*