Partial or total paralysis of the muscles that move the eyes. Ophthalmoplegia may be caused by disease of the muscles themselves, such as Graves’ disease, or by a condition that
affects the brain or the nerves supplying the eye muscles, such as stroke, a brain tumour, encephalitis, or multiple sclerosis.
Paralysis of the muscles of the EYE. Internal ophthalmoplegia refers to paralysis of the iris and ciliary body; external ophthalmoplegia refers to paralysis of one or all of the muscles that move the eyes.
n. paralysis of the muscles of the eye. Internal ophthalmoplegia affects the muscles inside the eye: the iris (which controls the size of the pupil) and also the ciliary muscle (which is responsible for *accommodation). External ophthalmoplegia affects the muscles moving the eye. Chronic progressive external ophthalmoplegia is a progressive disease of the extrinsic eye muscles leading to *ptosis and then paralysis of the muscles; eye movements become increasingly frozen in the primary position. Ophthalmoplegia may accompany *exophthalmos due to thyrotoxicosis. Internuclear ophthalmoplegia (INO), due to a lesion in the brainstem, is seen, for example, in patients with multiple sclerosis or stroke.