Genetic mutations in mitochondrial DNA, vitamin depletion, alcohol and tobacco abuse, and use of certain drugs can cause derangements in efficient transport of mitochondria, which can cause a primary or secondary optic neuropathy. Nutritional optic neuropathies
A nutritional optic neuropathy may be present in a patient with obvious evidence of under-nutrition (weight loss and wasting). Months of depletion are usually necessary to deplete body stores of most nutrients. Undernourished patients often have many vitamin and nutrient deficiencies and have low serum protein levels. However, the optic neuropathy associated with pernicious anemia and vitamin B12 deficiency can even be seen in well-nourished individuals. Gastric bypass surgery may also cause a vitamin B12 deficiency from poor absorption. Patients who have nutritional optic neuropathy may notice that colors are not as vivid or bright as before and that the color red is washed out. This normally occurs in both eyes at the same time and is not associated with any eye pain. They might initially notice a blur or fog, followed by a drop in vision. While vision loss may be rapid, progression to blindness is unusual. These patients tend to have blind spots in the center of their vision with preserved peripheral vision. In most cases, the pupils continue to respond normally to light. Toxic optic neuropathies
The most recognized cause of toxic optic neuropathy is methanol poisoning. This can be a life-threatening event that normally accidentally occurs when the person mistook or substituted, methanol for ethyl alcohol.
Correction of some abnormalities can be corrected with the use of extensive multidisciplinary craniofacial surgery. Physical therapy and occupational therapy are important to ensure they can live a normal and productive life. Monitoring the heart for defects is also common and there are medications to educe this risk or surgery is available to correct some of conditions. Epidemiology
Abruzzo-Erickson Syndrome is an extremely rare condition, prevalent among less than one in a million of individuals. As of 2021, only four cases have been characterized in literature. See also
CHARGE syndrome

References
External links
Abruzzo–Erickson syndrome at NIHs Office of Rare Diseases