The Pupils of Term and Preterm Infants

Isenberg, Sherwin J.; Dang, Yadavinder; Jotterand, Veronique

doi:10.1016/s0002-9394(14)73264-7

Cited by 27 publications

(4 citation statements)

References 6 publications

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“…These pupil diameters were chosen to mimic the average undilated and dilated pupil in lighting conditions similar to that of a primary care physician's office. 11,12 The view of the red reflex in the model eye with a direct ophthalmoscope was comparable to that of a real patient's eye with an optic nerve, retina, and vessels.…”

Section: Methodsmentioning

confidence: 78%

The Detection of Simulated Retinoblastoma by Using Red-Reflex Testing

Li¹,

Dk²,

D³

et al. 2010

Pediatrics

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Section: Methodsmentioning

confidence: 78%

The Detection of Simulated Retinoblastoma by Using Red-Reflex Testing

Li¹,

Dk²,

D³

et al. 2010

Pediatrics

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“…In infants, the pupil is smaller, less reactive to light, and less variable in size than in adults (Isenberg et al, 1989;Roarty and Keltner, 1990). To determine the average size of the pupil in baby squirrel monkeys, we took pictures of their eyes using a camera with a ring flash on a 100 mm macro lens.…”

Section: Methodsmentioning

confidence: 99%

The Representation of Retinal Blood Vessels in Primate Striate Cortex

Adams

Horton

2003

J. Neurosci.

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The blood vessels that nourish the inner retina cast shadows on photoreceptors, creating "angioscotomas" in the visual field. We have found the representations of angioscotomas in striate cortex of the squirrel monkey. They were detected in 9 of 12 normal adult animals by staining flatmounts for cytochrome oxidase activity after enucleation of one eye. They appeared as thin profiles in layer 4C radiating from the blind spot representation. Angioscotomas can be regarded as a local form of amblyopia. After birth, when light strikes the retina, photoreceptors beneath blood vessels are denied normal visual stimulation. This deprivation induces remodeling of geniculocortical afferents in a distribution that corresponds to the retinal vascular tree. Angioscotoma representations were most obvious in monkeys with fine ocular dominance columns and were invisible in monkeys with large, well segregated columns. In monkeys without columns, their width corresponded faithfully to the inducing retinal shadow, making it possible to calculate the minimum shadow required to produce a cortical representation. The "amblyogenic threshold" was calculated as the fraction of the pupil area eclipsed to trigger remodeling of geniculocortical afferents. It was found to be constant over retinal eccentricity, vessel size, and shadow size. Ambliogenic shadows only three to four cones wide were sufficient to generate a cortical representation, testifying to the remarkable precision of the cortical map. The representations of retinal blood vessels separated by only 0.65 degrees were resolvable in the cortex, yielding an upper limit on cortical resolution of 340 microm in layer 4C.

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“…All efforts were made to obtain pictures while the neonate was calm, generally while the infant was lying in a pram or being held by a nurse or parent. The same eye was photographed each time within individual neonates to control for anisocoria (i.e., unequal pupil sizes; Isenberg et al, 1989; Roarty and Keltner, 1990). …”

Section: Methodsmentioning

confidence: 99%

Infant pupillary response to methadone administration during treatment for neonatal abstinence syndrome: A feasibility study

Heil¹,

Gaalema²,

Johnston³

et al. 2012

Drug and Alcohol Dependence

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Background Pupil diameter is a frequently assessed objective index of the pharmacodynamic effects of opioids in adults, but to our knowledge has never been examined in infants. Such a measure could improve assessment and treatment of neonates exposed to opioids in utero. The present study examined changes in pupil diameter after opioid administration in opioid-exposed infants who required pharmacological treatment for neonatal abstinence syndrome (NAS) to test the feasibility of using pupil diameter as a measure of opioid effects in these infants. Methods Ten infants (2–7 days old) receiving methadone (0.4–0.5 mg every 12 hours) for the treatment of NAS participated. A picture of one of each infant's eyes was taken under controlled illumination conditions with a standard digital camera just prior to dosing and 0–1, 2–4, 5–7, and 8–10 hours after dosing. The diameters of the pupil and iris were measured and relative pupil diameter (pupil diameter expressed as a percentage of iris diameter) was analyzed. Results Mean (±SE) relative pupil diameter decreased significantly after dosing from 41±2% to 29±2%. After dosing, a significant increasing linear trend was observed over time, with values of 29±2%, 33±3%, 38±3%, and 41±3% at 0–1, 2–4, 5–7, and 8–10 hours after dosing. Conclusions Infant pupils respond to opioid administration in the same sensitive, orderly manner as is commonly observed in adults. Pupil diameter appears to be an objective, sensitive measure of neonatal response to opioids that may be a useful complement to, or perhaps at times a replacement for, observer-rated scale scores.

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The Pupils of Term and Preterm Infants

Cited by 27 publications

References 6 publications

The Detection of Simulated Retinoblastoma by Using Red-Reflex Testing

The Detection of Simulated Retinoblastoma by Using Red-Reflex Testing

The Representation of Retinal Blood Vessels in Primate Striate Cortex

Infant pupillary response to methadone administration during treatment for neonatal abstinence syndrome: A feasibility study

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