Consensual intraocular pressure changes resulting from unilateral extraocular muscle contraction

Direct stimulation of one lateral rectus muscle produced not only an increase in ipsilateral intraocular pressure but also changes in the contralateral intraocular pressure. These consensual intraocular pressure changes were independent of changes in respiration and systemic arterial pressure. The magnitude and type of consensual response varied and were not correlated with either the increase in ipsilateral muscle tension or the increase in ipsilateral intraocular pressure. Evidence has been given to support the hypothesis that the consensual response is neurogenic. The adequate stimulus for this reflex appeared to be increased tension produced by contraction of an extraocular muscle with an attendant increase in ipsilateral intraocular pressure, suggesting that the receptors lie at or near the junction of the muscle and sclera and respond more readily to changes in tension than to changes in length. The afferent pathway appeared to be other than the sixth cranial nerve and the efferent pathway was not somatic.