Optic Nerve Hypoplasia

A 9-month-old female infant is referred for evaluation of poor visual fixation and roving nystagmus starting at age 3 months. She was born at term to a mother who used alcohol in the first trimester and had no antenatal care. Neonatal history includes prolonged jaundice, hypoglycemia, and micropenis. On dilated fundoscopy, bilateral small pale optic discs are noted, estimated at one-third normal diameter (marked **A** in the diagram), with characteristic double ring signs. MRI brain shows thin optic nerves, absent septum pellucidum, and absent posterior pituitary bright spot. The small pale optic disc marked **A** reflects which of the following pathophysiological processes?