Purpose: We investigated the difference in clinical features and course of treatment for nine cases of cyclic strabismus comparing esotropia with exotropia.
Materials and methods: We retrospectively reviewed nine patients with cyclic strabismus (eight patients with esotropia and one with exotropia) treated at the National Center for Child Health and Development from 2003 to 2018 and compared the outcomes with the previous cases.
Results: The ages at onset of cyclic strabismus ranged from 3 to 8 years. In seven patients, the onset was acute. In two, the condition developed from accommodative esotropia; five, three, and one of these had 48-, 24-, and 72-h cycles, respectively. On the days when strabismus did not occur, all showed orthophoria, and the stereoacuity ranged from 40 to 100 s. On strabismic days, all patients showed concomitant strabismus with poor binocular vision and the squint angles were 30-60 prism diopters (PD) at distance and near; four patients had diplopia. In six patients, the cycle converted to constant strabismus, and all patients underwent surgery that resulted in favorable ocular alignment and the cycle resolved. One patient with exotropia developed myopic ani so metropia and convergence insufficiency exotropia of 30 PD at postoperative three years. However, wearing of spectacles and convergence training improved her ocular alignment to 6 PDs of exophoria. Orthophoria and favorable stereopsis were postoperatively maintained in all patients from 6 to 157 months.
Conclusion: Although the surgical outcomes for cyclic strabismus were satisfactory, cyclic exotropia required treatment with convergence insufficiency.
Nippon Ganka Gakkai Zasshi (J Jpn Ophthalmol Soc) 124: 995-1002, 2020.