Normal neonatal values of ophthalmic and central retinal artery blood flow velocities.

Purpose: To define standard values of blood flow velocities and indices in the ophthalmic and central retinal arteries in the neonatal period.

Methods: Forty-two healthy full-term neonates comprised the study population. A color Doppler with mechanical sector probe was used for measuring blood flow velocity in the ophthalmic and central retinal arteries. Systolic, end diastolic, and mean-enveloped velocities were measured, and the resistance index and pulsatility index were calculated.

Results: Ophthalmic artery Doppler velocities were similar on the first and third days of life, but increased significantly on the fifth and seventh days of life; resistance index significantly increased during the first week of life, whereas pulsatility index did not change significantly. Doppler velocities of the central retinal artery were similar on the first and third days; they show a delayed increase compared to the ophthalmic artery. Central retinal artery blood flow velocities increased significantly from the third to seventh postnatal day. Resistance index also increased between the first two days and on the fifth and seventh postnatal days, while pulsatility index did not change.

Conclusion: These data constitute a starting point for studying the possible relationship between eye circulation and pathogenesis of retinopathy of prematurity.