Progressive external ophthalmoplegia, left eye

This code signifies a chronic, progressive weakness of the extraocular muscles affecting the left eye, leading to impaired eye movement. It is a form of mitochondrial myopathy characterized by gradual onset and worsening of ophthalmoplegia without other neurological deficits initially.

Apply this code when documentation specifies progressive external ophthalmoplegia isolated to the left eye. This diagnosis is typically supported by neurological examination findings demonstrating restricted ocular motility and potentially electromyography or muscle biopsy results.

• Ensure documentation clearly specifies "left eye" to avoid laterality errors.
• Distinguish from other forms of ophthalmoplegia, such as acute or paralytic, which have different codes.
• Consider co-occurring systemic manifestations of mitochondrial disease, which may require additional codes.