Progressive external ophthalmoplegia

**Definition:** Chronic ophthalmoplegia is characterised by progressive weakness of ocular muscles and levator muscle of the upper eyelid. The condition is mainly manifested in adults. It may be totally and permanently isolated, however in a minority of cases it is associated with skeletal myopathy, which causes abnormal fatigability and even permanent muscle weakness. In this case the affection is still termed isolated progressive external ophthalmoplegia. A large proportion of chronic ophthalmoplegias presents with multisystemic pattern of signs: neurological signs (hearing loss, retinopathy, cerebellar disorders, peripheral neuropathy, etc.), endocrine (diabetes, hypogonadism, hypoparathyroidism, etc.), kidney (kidney failure, tubulopathy, etc.), and heart disorders (conduction disorders, myocardiopathy, etc.).