Setting-Sun phenomenon

The eyes appear driven downward in this infant with hydrocephalus.

Setting-Sun Phenomenon

The setting-sun phenomenon is an ophthalmologic sign in young children resulting from upward-gaze paresis. In this condition, the eyes appear driven downward, the sclera may be seen between the upper eyelid and the iris, and part of the lower pupil may be covered by the lower eyelid. Pathogenesis of this sign is not well understood, but it seems to be related to aqueductal distention with compression of periaqueductal structures secondary to increased intracranial pressure.

More details:  📖 Merritt’s Neurology Handbook 10th Edition

CT scan, showing marked hydrocephalus in infant with setting-sun eye phenomenon

References

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