Patients with LHON mutations usually do not have any symptoms until early adult life, when a trigger process is thought to lead to acute vision loss. However, the cause of these triggers and the mechanism behind them is still poorly understood.
However, smoking and alcohol have been linked to LHON. Therefore, it is recommended to avoid smoking and excessive alcohol intake if you are a carrier of LHON mutations. More information can be found in the below articles:
Some drugs, such as some antibiotics, have the potential to cause damage to mitochondria. Since both affected and non-affected carriers are known to have weaknesses in their mitochondria, limiting or avoiding these where possible is important. You can review this list of medications on the mito action website with your GP or consultant before taking any new medicine.