A new photographic method for measurement of the otolithic ocular countertorsion reflex (OCR) uses a portable head frame unit to control the position of gaze and the camera. Mean ocular countertorsion of the two eyes (summed) after 50° lateral head tilt was 10.8° and 11.8° in 35 normals on right and left tilt respectively with the same large subject to subject and eye to eye variation and 1° spontaneous fluctuation in eye position reported earlier. Tilting the head and body en bloc vs tilt of the head on the neck revealed similar OCR values, both in normals and in four subjects with severe bilateral labyrinthine damage, suggesting that neck afferents contribute very little to the OCR. Gaze shifts prior to photography did not increase OCR error. Preliminary results in patients with positional vertigo revealed a tendency for lesser countertorsion when the head was tilted towards the affected ear.
Nelson JR, Cope D, Kan L. The Otoliths and the Ocular Countertorsion Reflex. Arch Otolaryngol. 1971;94(1):40–50. doi:10.1001/archotol.1971.00770070076008
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