Viktoria Bau1, Maike Sievert, Peter Roggenkämper, Stephan Zierz. 1. Universitätsklinik und Poliklinik für Augenheilkunde der Martin-Luther-Universität Halle-Wittenberg, Ernst-Grube-Strasse 40, 06097, Halle (Saale), Germany. viktoria.bau@medizin.uni-halle.de
Abstract
BACKGROUND: Cyclic strabismus is a rare disorder in which strabismus and orthotropia regularly alternate over a period of mostly 48 h. It may occur spontaneously, upon squint surgery, or in association with lesions of the central nervous system. In most cases the deviations are convergent. METHODS: Clinical case report. RESULTS: A 34-year-old woman with bilateral recurrent ocular myositis for 2 years had developed cyclic vertical deviation 6 months after clinical remission. A hypotropia of the left eye alternated with an orthotropia, following a 48-h rhythm. Three months after recession of the inferior rectus muscle the alternating squint had disappeared. DISCUSSION: The aetiology of cyclic eye deviations, most of them occurring in a constant rhythm, is not known. The association with lesions of the central nervous system indicates a primary central dysregulation of a "biological clock". Their well-known occurrence, however, after squint surgery and, as in the present case, after orbital myositis, suggests that alteration of peripheral structures may contribute to a central dysregulation. Squint surgery seems to be the treatment of choice, even in rare cases with vertical deviations.
BACKGROUND: Cyclic strabismus is a rare disorder in which strabismus and orthotropia regularly alternate over a period of mostly 48 h. It may occur spontaneously, upon squint surgery, or in association with lesions of the central nervous system. In most cases the deviations are convergent. METHODS: Clinical case report. RESULTS: A 34-year-old woman with bilateral recurrent ocular myositis for 2 years had developed cyclic vertical deviation 6 months after clinical remission. A hypotropia of the left eye alternated with an orthotropia, following a 48-h rhythm. Three months after recession of the inferior rectus muscle the alternating squint had disappeared. DISCUSSION: The aetiology of cyclic eye deviations, most of them occurring in a constant rhythm, is not known. The association with lesions of the central nervous system indicates a primary central dysregulation of a "biological clock". Their well-known occurrence, however, after squint surgery and, as in the present case, after orbital myositis, suggests that alteration of peripheral structures may contribute to a central dysregulation. Squint surgery seems to be the treatment of choice, even in rare cases with vertical deviations.