Optic atrophy 1 (OPA1) is an important protein on the inner mitochondrial membrane, mainly involved in maintaining mitochondrial fusion, structural integrity, and function. OPA1 consists of multiple isoforms, which can be generated through alternative splicing and protein cleavage. It is widely expressed in various tissues, particularly at higher levels in tissues with high energy demands such as the heart, muscles, and brain. OPA1 plays a key role in regulating mitochondrial dynamics, cell apoptosis, energy metabolism, and oxidative stress response. Mutations in the OPA1 gene are associated with various diseases, including the common inherited eye disease autosomal dominant optic atrophy (DOA) and some mitochondrial diseases.