Five-year post-onset visual acuity trajectories in Japanese Leber hereditary optic neuropathy: a longitudinal analysis by age, sex, and mtDNA mutation.

In this cohort, onset at ≤19 years was associated with earlier and greater visual recovery, whereas onset at ≥50 years was associated with persistently worse vision. Age at onset is an important modifier of 5-year visual prognosis in bilaterally affected LHON.