Chronic Progressive External Ophthalmoplegia (CPEO)
Chronic Progressive External Ophthalmoplegia (CPEO) is a mitochondrially inherited disorder that is characterized by ptosis and ophthalmoplegia secondary to progressive weakness of the extraocular muscles. There is often also associated orbicularis weakness. While the mean age of diagnosis is generally in the fourth or fifth decade, the disease can manifest in infancy and childhood as well. The majority of patients present with single deletions in the mitochondrial DNA, and transmission is maternal.
The clinical features of this disorder are ptosis and progressive ophthalmoplegia. In later stages, the eyes are eventually fixed in primary gaze, or slightly infraducted. These clinical features are ascribed to a myopathy selectively affecting the extraocular muscles and levator complex; biopsy of the affected muscles typically demonstrates ragged red fibers and atrophy of selected muscle fibers.
Kearns-Sayre syndrome is characterized by the clinical features of CPEO combined with pigmentary retinopathy, complete heart block and cerebellar ataxia. Patients with CPEO must be evaluated for this potentially fatal syndrome and treated accordingly.
Treatment of the ptosis in this condition is primarily surgical. The use of coenzyme Q has been reported but has not been shown to be effective in treating this condition (Caballero 2007).
Please see our dedicated CPEO EyeRounds case for a more extensive discussion of this condition.