Erythropoietin and retinopathy of prematurity.

Erythropoietin (EPO) is a glycoprotein that regulates many functions of an organism: It stimulates the production of red blood cells and it has angiogenic and neuroprotective properties in newborn infants. Retinopathy of prematurity (ROP) is a frequent cause of visual impairment in preterm newborn infants and it has two distinct phases in which hypoxia-induced angiogenic factors are involved. The relationship between EPO and ROP is derived from the observation of studies done on the haematopoietic effect of EPO. The first observations suggested that a precocious treatment with EPO increases the risk of ROP, while the most recent reports suggested that the late treatment with high doses of rhEPO can increase the risk of ROP. All these studies were not designed to demonstrate the relationship between EPO and ROP. Further studies specifically designed should be performed. New ongoing studies on the neuroprotective role of EPO should consider this objective. In the mean time the use of EPO in the neonatal period should be cautious, mainly in very low birth weight infants.

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.