Chronic progressive external ophthalmoplegia

Chronic progressive external ophthalmoplegia, abbreviated CPEO, is a type of eye disorder characterized by a slowly progressive inability to move the eyes and eyebrows. It is often the only feature of mitochondrial disease, and in that case the term CPEO may be given as the diagnosis. In other people with mitochondrial disease it occurs as part of a syndrome involving more than one part of the body, such as Kearns-Sayre syndrome. Occasionally it may be caused by conditions other than mitochondrial diseases. The name describes the picture: it is chronic and progressive, it affects the external muscles that move the eyes, and the paralysis is called ophthalmoplegia.