Abstract: Chronic Progressive External Ophthalmoplegia (CPEO) is a rare mitochondrial disorder characterized by progressive weakness and paralysis of the extraocular muscles, leading to ophthalmoplegia and ptosis. This article offers a comprehensive review of CPEO, covering its pathogenesis, clinical manifestations, diagnostic modalities, treatment strategies, and recent innovations. By delving into the complexities of CPEO, ophthalmologists can enhance their understanding and management of this condition for improved patient care.

Introduction: Chronic Progressive External Ophthalmoplegia (CPEO) poses diagnostic and therapeutic challenges due to its heterogeneous presentation and underlying mitochondrial dysfunction. Understanding the pathophysiology and clinical features is crucial for timely diagnosis and appropriate management.

Pathogenesis: CPEO arises from mitochondrial DNA mutations affecting the function of the electron transport chain, leading to impaired energy production in extraocular muscles. Mitochondrial deletions, point mutations, and nuclear gene mutations contribute to the pathogenesis of CPEO.

Clinical Features: Patients with CPEO typically present with bilateral ptosis, limitation of extraocular movements, and ophthalmoplegia, which progress slowly over time. Additional features may include facial weakness, dysphagia, and proximal limb weakness, reflecting the systemic nature of mitochondrial dysfunction.

Diagnostic Modalities: Diagnosis of CPEO involves a combination of clinical evaluation, neuroimaging studies, electromyography (EMG), and genetic testing. Muscle biopsy may reveal characteristic mitochondrial abnormalities, aiding in confirmation of the diagnosis.

Management Strategies: Management of CPEO focuses on symptomatic relief and supportive care, as no curative treatment currently exists. Strategies may include ptosis correction surgery, prism glasses for diplopia, and physical therapy to improve functional capacity. Coenzyme Q10 supplementation and idebenone therapy have been investigated as potential disease-modifying agents.

Recent Advances: Recent advancements in CPEO research include targeted therapies aimed at restoring mitochondrial function, gene therapy approaches for mitochondrial DNA mutations, and novel imaging techniques for assessing mitochondrial dysfunction in vivo.

Conclusion: Chronic Progressive External Ophthalmoplegia (CPEO) presents a complex clinical entity requiring a multidisciplinary approach for optimal management. By staying abreast of the latest research and innovations in CPEO, ophthalmologists can deliver comprehensive care and improve outcomes for affected individuals.

For further reading and reference:

• National Organization for Rare Disorders (NORD) – Chronic Progressive External Ophthalmoplegia: https://rarediseases.org/rare-diseases/chronic-progressive-external-ophthalmoplegia/
• Genetics Home Reference – CPEO: https://ghr.nlm.nih.gov/condition/chronic-progressive-external-ophthalmoplegia
• Journal of Neuro-Ophthalmology – Recent Advances in CPEO Research: https://journals.lww.com/jneuro-ophthalmology/pages/default.aspx