{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,9,1]],"date-time":"2025-09-01T17:10:11Z","timestamp":1756746611503,"version":"3.44.0"},"reference-count":31,"publisher":"BMJ","issue":"1","content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Open Ophth"],"accepted":{"date-parts":[[2017,10,30]]},"published-print":{"date-parts":[[2017,11]]},"abstract":"<jats:sec>\n                  <jats:title>Objective<\/jats:title>\n                  <jats:p>To quantify fixation stability of the upward gaze in patients with myasthenia gravis (MG) using an eye tracker.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Methods and analysis<\/jats:title>\n                  <jats:p>In this study, 21 normal subjects, 5\u2009patients with MG with diplopia, 5\u2009patients with MG without diplopia and 6 patients with superior oblique (SO) palsy were included. Subjects fixated on a target in the upward direction for 1\u2009min. The horizontal (X) and vertical (Y) eye positions were recorded using an eye tracker. Fixation stability was first quantified using the bivariate contour ellipse areas (BCEA) of fixation points as an index of whole stability. Then, the SDs of the X and Y eye positions (SDX and SDY, respectively) were quantified as indices of directional stability, with the data divided into three 20\u2009s fractions to detect temporal fixation fluctuation.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Results<\/jats:title>\n                  <jats:p>BCEAs were larger in patients with MG (both with and without diplopia) than normal subjects and patients with SO palsy, without significant differences among the three 20\u2009s fractions. Compared with normal subjects, SDXs were larger only in patients with MG with diplopia; SDYs were larger in both patients with MG with and without diplopia. In addition, SDYs in patients with MG with diplopia were larger than those in patients with MG without diplopia and patients with SO palsy. Furthermore, a significant difference among the three 20\u2009s fractions was detected for SDYs in patients with MG with diplopia.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Conclusion<\/jats:title>\n                  <jats:p>Patients with MG, especially those with diplopia, exhibit fixation instability in the upward gaze. Non-invasive quantification of fixation stability with an eye tracker is useful for precisely identifying MG-specific fatigue characteristics.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Trial registration number<\/jats:title>\n                  <jats:p>UMIN000023468; pre-results.<\/jats:p>\n               <\/jats:sec>","DOI":"10.1136\/bmjophth-2017-000072","type":"journal-article","created":{"date-parts":[[2017,11,17]],"date-time":"2017-11-17T20:10:07Z","timestamp":1510949407000},"page":"e000072","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":4,"title":["Fixation stability of the upward gaze in patients with myasthenia gravis: an eye-tracker study"],"prefix":"10.1136","volume":"2","author":[{"given":"Miharu","family":"Mihara","sequence":"first","affiliation":[{"name":"Department of Ophthalmology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan"},{"name":"Department of Integrative Neuroscience, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Atsushi","family":"Hayashi","sequence":"additional","affiliation":[{"name":"Department of Ophthalmology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kazuya","family":"Fujita","sequence":"additional","affiliation":[{"name":"Department of Ophthalmology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ken","family":"Kakeue","sequence":"additional","affiliation":[{"name":"Department of Ophthalmology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ryoi","family":"Tamura","sequence":"additional","affiliation":[{"name":"Department of Integrative Neuroscience, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"239","published-online":{"date-parts":[[2017,11,16]]},"reference":[{"key":"2025090109392379000_2.1.e000072.1","doi-asserted-by":"publisher","DOI":"10.1016\/j.jns.2011.03.004"},{"key":"2025090109392379000_2.1.e000072.2","doi-asserted-by":"crossref","first-page":"671","DOI":"10.1007\/s13760-015-0460-x","article-title":"Patients with ocular symptoms referred for electrodiagnosis: how many of them suffer from myasthenia gravis?","volume":"115","author":"Zambelis","year":"2015","journal-title":"Acta Neurol Belg"},{"key":"2025090109392379000_2.1.e000072.3","unstructured":"Japonica SN . 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