Review Question - QID 100878

Excess supplemental oxygen in neonates may result in retinopathy of prematurity (ROP), which can lead to blindness.

ROP is a disease seen in premature infants that results from abnormal angiogenesis in the retina. An insult such as hypertension, hypoxia, or hyperoxia disrupts normal proliferation of blood vessels, which can lead to retinal detachment and blindness in severe cases.

Mills reviews opthalmologic issues in childhood, with high-yield clinical photos. He notes that children born prematurely are at risk for ROP and, later, high refractive error, strabismus, and amblyopia and recommends that children born very prematurely should have more frequent complete eye examinations.

Fleck and McIntosh review evolving knowledge of the pathogenesis of ROP. They note that oxygen levels are significantly higher postnatally than in utero and that oxygen therapy given for lung disease in premature infants increases levels further. Abnormally high oxygen concentrations thus disrupt VEGF-mediated retinal endothelial cell proliferation, causing retinal hypoxia which then leads to abnormal retinal vascularization and possible blindness.

Illustration A shows tortuous, hyper-proliferative blood vessels on indirect opthalmoscopy characteristive of ROP.
Illustration B shows stages of ROP from Stage 1 (least severe) to Stage 5 (most severe, retrolental fibroplasia, likely blindness).

Incorrect answers:
Answer 1: Atelectasis describes collapse of the alveoli seen in neonatal respiratory distress syndrome.
Answer 2: Anosmia is loss of smell.
Answer 3: Atopy is a predisposition toward allergic reactions.
Answer 5: Oxygen therapy may be used in the treatment of cardiac anomalies, but use of oxygen does not itself cause cardiac anomalies.