Leber Hereditary Optic Neuropathy (LHON)

A 22-year-old male medical student presents with sudden painless central vision loss in the right eye over 2 weeks, followed by similar vision loss in the left eye 6 weeks later. He is a heavy smoker (15 cigarettes/day) and has a family history of early-onset blindness in maternal relatives. Fundoscopy reveals the classic LHON triad. The structure marked **B** in the diagram (peripapillary telangiectatic microangiopathy) is a characteristic finding in the acute phase of LHON. Which of the following best explains the pathophysiological basis of this vascular abnormality in LHON?