Mitochondrial dysfunction underlying outer retinal diseases

•The outer retina has a high metabolic demand associated with numerous mitochondria.•Mitochondrial dysfunction in RPE cells might contribute to AMD pathology.•Ageing is a crucial factor in mitochondrial dysfunction in the outer retina.•Oxidative stress and mtDNA mutations importantly underlie outer retinal diseases.•Mitochondria represent a weak link in the antioxidant defenses in the outer retina.

Dysfunction of photoreceptors, retinal pigment epithelium (RPE) or both contribute to the initiation and progression of several outer retinal disorders. Disrupted Müller glia function might additionally subsidize to these diseases. Mitochondrial malfunctioning is importantly associated with outer retina pathologies, which can be classified as primary and secondary mitochondrial disorders. This review highlights the importance of oxidative stress and mitochondrial DNA damage, underlying outer retinal disorders. Indeed, the metabolically active photoreceptors/RPE are highly prone to these hallmarks of mitochondrial dysfunction, indicating that mitochondria represent a weak link in the antioxidant defenses of outer retinal cells.