ocular myopathy

Last reviewed 10/2022

Ocular myopathy is rare. The principal causes of ophthalmoplegia due to disorder of the ocular muscles are myasthenia gravis and exophthalmic ophthalmoplegia.

Characteristic features:

  • distribution of muscular weakness not explicable in terms of a nuclear lesion
  • both eyes usually affected

In myasthenia, there is usually ptosis, and ocular impairment ranging from weakness of a single ocular muscle of one eye to virtual paralysis of all muscles of both eyes. The weakness rapidly increases with fatigue and muscular power is improved by neostigmine and other similar drugs.

In exophthalmic ophthalmoplegia, the weakness first affects the elevators and abductors, is often bilateral and is associated with exophthalmos and retraction of the upper lid. The conjunctivae are oedematous and later congested.