Approach to leukocoria (pediatrics) Quiz: Ace Your Exams

A 4-week-old premature infant born at 28 weeks’ gestation, with a birth weight of 900 grams, is being evaluated in the neonatal intensive care unit (NICU). The pregnancy was complicated by preeclampsia and a positive Group B Streptococcus (GBS) test, for which treatment was given. The infant required intubation at birth, received two doses of surfactant, and remained on mechanical ventilation with 100% oxygen concentrations for three weeks. Temperature is 37°C (98.6°F), pulse is 166/min, respirations are 37/min, blood pressure is 82/47 mmHg, and oxygen saturation is 95% on a nasal cannula delivering 60% FiO₂. On physical examination, the infant appears active. The head is normocephalic with an open, soft anterior fontanelle. Cardiopulmonary examination shows normal heart sounds without murmurs and clear breath sounds bilaterally. The abdomen is soft and non-distended with normal bowel sounds. Extremities are symmetric with normal tone and movement. Ophthalmologic examination reveals a white pupillary reflex without lens opacity. Fundoscopy shows vitreous haze and neovascularization in both eyes, without intraocular masses or hemorrhage. Which of the following is the most significant risk factor for this infant's ophthalmologic findings?