sun-setting eyes

A 3-month-old boy, born full-term via normal spontaneous vaginal delivery to a gravida 2 para 1 mom with negative prenatal labs, presents with abnormal eye movement and position. His parents report 2 days of an increase in bulging of the soft spot, head size, and abnormal eye movement. He has not been able to look at his mother “like he used to.” This is associated with an increase in fussiness, poor feeding, and non-bilious, non-bloody vomiting. He also had increased sleepiness and difficulty waking up for feedings overnight.

The patient has normal urination with no weight loss, diarrhea, or fever.

Vitals: Normal for patient’s age


  • Well appearing with head circumference of 19 inches
  • Alternating episodes of alertness and sleepiness


  • Bulging anterior fontanelle, frontal bossing, and downward gazing eyes
  • Pupils equal, round, and reactive, 4 mm bilaterally
  • Oral mucosa moist
  • Neck supple, but patient unable to lift head while in prone position

Skin: Dry hair and spots of hypopigmentation on face

The remainder of the exam was unremarkable, including full range of movement of his extremities, normal ankle clonus, and patellar deep tendon reflex.

Unremarkable complete blood count (CBC), comprehensive metabolic panel (CMP), and thyroid stimulating hormone (TSH)

Yes, a head circumference of 19 inches is abnormal.

For this patient, at his 2-month well-child check, he had a head circumference of seventeen inches, which plots out at the 99th percentile. At 3 months, a head circumference of 19 inches was greater than the 99th percentile.

The patient’s eyes are abnormal and are often described as sun-setting eyes.

The photo demonstrates macrocephaly with frontal bossing, bulging fontanelle, and sun-setting eyes. The physical exam in conjunction with difficulty arousing the baby for feedings, increasing fussiness, and vomiting is concerning for hydrocephalus.

Early signs of hydrocephalus include increasing head circumference, macrocephaly, irritability, fussing, somnolence, vomiting, and inability to control head movement or resistance to head movement. One of the earliest signs is the finding of sun-setting eyes which is seen in hydrocephalus in 40% of cases [1]. Sun-setting eyes can actually present in healthy newborns up to 7 months of age and can be pathological if it is persistent. Sun-setting eyes are usually caused by an upward gaze paresis in the case of hydrocephalus.

Intracranial imaging was done which demonstrated marked diffuse ventriculomegaly involving the bilateral lateral ventricles, third ventricle, and fourth ventricle. These are findings consistent with communicating hydrocephalus. There was no definitive evidence of focal abnormal densities involving the brain. Hydrocephalus in newborns requires immediate brain imaging and neurosurgical consultation to prevent long-term sequelae, including poor development of cognitive function, visual loss, respiratory arrest due to tonsillar herniation, and brain stem compression.

Take-Home Points

  • Sun-setting eyes can be an early sign of elevated intracranial pressure and hydrocephalus.
  • Emergent imaging is required in infants with difficulty arousing for feedings, fussiness, and vomiting in conjunction with macrocephaly, bulging fontanelle, and sun-setting sign.
  1. Boragina M, Cohen E. An infant with the “setting-sun” eye phenomenon. CMAJ. 2006;175(8):878. doi:10.1503/cmaj.060507. PMID: 17030938
  2. Vertinsky AT, Barnes PD. Macrocephaly, increased intracranial pressure, and hydrocephalus in the infant and young child. Top Magn Reson Imaging. 2007;18(1):31-51. doi:10.1097/RMR.0b013e3180d0a753. PMID: 17607142
  3. Tzekov C, Cherninkova S, Gudeva T. Neuroophthalmological symptoms in children treated for internal hydrocephalus. Pediatr Neurosurg. 1991;17(6):317-320. doi:10.1159/000120617. PMID: 1840820
  4. Yoshikawa H. Benign “setting sun” phenomenon in full-term infants. J Child Neurol. 2003;18(6):424-425. doi:10.1177/08830738030180061601. PMID: 12886979

Krista McEwan

Krista McEwan

Medical Student
Southern Illinois University, School of Medicine
Krista McEwan

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Myto Duong, MB, BCh, BAO, MSc, FAAP

Myto Duong, MB, BCh, BAO, MSc, FAAP

Associate Professor
Pediatric Emergency Medicine
Department of Emergency Medicine
Southern Illinois University, School of Medicine
Myto Duong, MB, BCh, BAO, MSc, FAAP

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