Chronic Progressive External Ophthalmoplegia - Chronic progressive external ophthalmoplegia (CPEO) is a disorder characterized by slowly progressive paralysis of the extraocular muscles. Patients usually experience bilateral, symmetrical, progressive ptosis, followed by ophthalmoparesis months to years later. Ciliary and iris muscles are not involved.CPEO is the most frequent manifestation of ...

Kearns-Sayre syndrome information sheet compiled by the National Institute of Neurological Disorders and Stroke (NINDS).