Causes, background, and characteristics of binocular diplopia in the elderly

We evaluated the background and characteristics of elderly patients with binocular diplopia including diseases caused by abnormalities in orbital pulleys.

Retrospective.

The participants were 236 patients aged 60 years or older who visited Kitasato University Hospital complaining of binocular diplopia. We classified strabismus by types and investigated the causes for each group. We diagnosed orbital pulley disorders using magnetic resonance imaging (MRI). Patients with orbital pulley disorders exhibited esotropia and/or vertical strabismus and did not present with cranial nerve palsy, systemic illness, or ocular injury.

Classification of strabismus types was: exotropia (24.2%); esotropia (25.0%); vertical strabismus (30.1%), combined strabismus (20.8%). There were 50.9% cases of strabismus associated with vertical deviation. The causes of disease in each group were as follows: in the exotropia group, 50.9% convergence insufficiency exotropia, 21.1% basic exotropia; in the esotropia group: 35.6% orbital pulley disorder 33.9% sixth cranial nerve palsy; in the vertical strabismus group: 32.4% forth cranial nerve palsy, 31.0% orbital pulley disorder; in the combined strabismus group: 28.6% orbital pulley disorder, 28.6% forth cranial nerve palsy.

About half of the elderly patients with binocular diplopia exhibited vertical deviation. In addition, binocular diplopia was often caused by orbital pulley disorders. It is the first epidemiological study focusing on orbital pulley disorders diagnosed on the basis of MRI.