2020–2021 BCSC Basic and Clinical Science Course™
6 Pediatric Ophthalmology and Strabismus
Part I: Strabismus
Chapter 9: Exodeviations
Other Forms of Exotropia
Dissociated Horizontal Deviation
Dissociated strabismus complex may include vertical, horizontal, and/or torsional components (see Chapter 2 and Chapter 11). It may be associated with infantile esotropia. When a dissociated abduction movement is predominant, the condition is called dissociated horizontal deviation (DHD). Though not a true exotropia, DHD can be confused with a constant or intermittent exotropia. Dissociated vertical deviation and latent nystagmus often coexist with DHD (Fig 9-2). In rare cases, patients may manifest both DHD and intermittent esotropia. DHD must be differentiated from anisohyperopia associated with intermittent exotropia, in which the exotropic deviation is present during fixation with the normal eye but is masked during fixation with the hyperopic eye because of accommodative convergence. Treatment of DHD usually consists of unilateral or bilateral lateral rectus recession in addition to any necessary oblique or vertical muscle surgery.
Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.