OCTA Evaluation of Retinal Vascularization in Preterm Infants With or Without Bronchopulmonary Dysplasia

Retinal vascularization in humans develops between the 16th and 36th weeks of gestational age, progressing centrifugally from the optic disc. In the case of premature birth, the immature peripheral retina is at risk of ischemia due to incomplete vascular development. This lack of perfusion in the retinal periphery leads to abnormal secretion of pro-angiogenic factors, promoting the formation of abnormal neovessels, which may be complicated by vitreous hemorrhage and tractional retinal detachment, resulting in permanent visual impairment.

Conversely, it is known that premature infants have a smaller central avascular zone compared with full-term infants. This region of the retina, where 90% of cones are concentrated, must remain free of vascular structures to allow optimal vision.

Prematurity is often associated with respiratory fragility. It frequently requires ventilatory support in the form of oxygen therapy, either invasive (orotracheal intubation) or non-invasive, which induces reflex arteriolar vasoconstriction and worsens the ischemia already present in the periphery.

Clinically, after birth, ocular disorders are more frequently observed in premature children, including amblyopia, impaired contrast sensitivity, refractive errors, strabismus, and optic nerve abnormalities.

It is therefore reasonable to question whether subclinical retinal vascular changes exist, detectable by OCT angiography, and associated with these clinical differences.