THE LOSS OF FUSION IN ADULTS WITH INTRACTABLE DIPLOPIA (CENTRAL FUSION DISRUPTION)

Authors

  • J. A. PRATT-JOHNSON MB, FRCS(C),

    Corresponding author
    1. Department of Ophthalmology, B.C. Children's Hospital, and the Department of Ophthalmology, University of British Columbia, Vancouver, Canada
      Children's Hospital, 4480 Oak Street, Vancouver, B.C. V6H 3V4, Canada.
    Search for more papers by this author
  • G. TILLSON DBO(T)

    1. Department of Ophthalmology, B.C. Children's Hospital, and the Department of Ophthalmology, University of British Columbia, Vancouver, Canada
    Search for more papers by this author

Children's Hospital, 4480 Oak Street, Vancouver, B.C. V6H 3V4, Canada.

Abstract

People over the age of 10 years can lose their fusion ability. This acquired disruption of fusion gives rise to intractable diplopia without suppression. An involuntary vertical bobbing movement of the non-fixing eye, present only with both eyes open, occurs at or near the angle of superimposition. This appears to be a unique and characteristic sign of acquired disruption of fusion and was present in all cases. Other causes of diplopia are mentioned and differentiated. Acquired central fusion disruption usually results from serious head injury. Partial recovery may occur but is unlikely. Sensory deprivation of at least 31/2 years' duration due to poor vision in one eye resulting from a traumatic cataract and sometimes subsequent uncorrected unilateral aphakia caused loss of fusion in 15 patients. The practical implications with regard to intraocular lenses and unilateral aphakia is discussed. Less commonly, vascular, neoplastic and presumed inflammatory lesions in the mid-brain area cause central fusion disruption.

Ancillary