Postnatal growth of the human optic nerve

Area of Science:

• Ophthalmology
• Pediatric Neurology
• Developmental Biology

Background:

• The length of the adult human optic nerve (ON) is known, but data on newborn ON length and growth rates are limited.
• Understanding ON development is crucial for pediatric ophthalmology and neurology.

Purpose of the Study:

• To determine the average length of the normal full-term newborn human optic nerve (ON).
• To evaluate the in vivo anteroposterior growth rate of the human ON from birth to adulthood.

Main Methods:

• Utilized MRI scans from a cohort of normal newborns, with some rescanned at one year of age.
• Included additional age groups to establish growth trajectories.
• Calculated average newborn ON length and its subsequent growth rate.

Main Results:

• The average length of a newborn human ON is 25.3 ± 0.3 mm (globe to chiasm).
• The ON elongates by approximately 80% after birth.
• Maximum growth speed occurs within the first three years of life, reaching full length by age 15.

Conclusions:

• The human optic nerve (ON) undergoes significant growth in the first three years of life and continues developing into the second decade.
• These findings are vital for pediatric interventions affecting orbital growth and for assessing risks associated with early childhood oncological procedures.