Monofixation Syndrome Clinical Presentation

Updated: Sep 14, 2021
  • Author: Sharmila Segar, MD; Chief Editor: Donny W Suh, MD, MBA, FAAP, FACS  more...
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Monofixation syndrome is generally an asymptomatic condition that is diagnosed by a physical examination. Patients should be asked whether they have a history of eye muscle surgery, amblyopia, or retinal disease, as well as a family history of strabismus.

Adults with subnormal stereovision, mild anisometropia, and subtle asymmetry in best-corrected vision may have undiagnosed monofixation syndrome.


Physical Examination

Patients may have an esotropia or exotropia measuring 8 prism diopters or fewer with a simultaneous prism cover test. Monofixation syndrome can also be observed in patients with vertical strabismus with a deviation measuring 6 prism diopters or fewer. [7]  Stereoacuity as measured with polarized glasses will show reduced stereopsis, ranging from 3000 arc seconds to 67 arc seconds. There are many specialized tests to identify the presence of peripheral fusion with a central suppression scotoma, including vectographic projections of Snellen letters, Worth 4-dot test, Bagolini lenses, and 4-Prism diopter base-out test. [2]