Oculocardial reflex

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The oculocardial reflex ("eye-heart reflex ") occurs when pressure is applied to the eyeball (Bulbus oculi) or when the eye muscles are pulled. The organism reacts with a drop in heart rate ( bradycardia ) and blood pressure ( hypotension ) as well as with deeper breathing and nausea . This can lead to incidents during eye surgery.

nomenclature

The oculocardial reflex has also been known as the Aschner bulb pressure test, Aschner bulb reflex, Aschner oculocardial reflex, Aschner phenomenon, Aschner Dagnini reflex, Aschner's phenomenon , Aschner's test . The reflex phenomenon was described almost simultaneously by Aschner and Dagnini. A few months before Aschner's communication, Dagnini published the reflex phenomenon observed in two comatose patients on June 17, 1908, and interpreted it as an influence of peripheral vagus stimulation . Aschner's publication on the same topic followed independently in October 1908. Aschner had first seen the bulb pressure experiment in a lecture by Wagner-Jauregg and explained it experimentally. The inevitable question of the priority of the first person to describe this phenomenon dominated the scientific discussion for some time.

Globe pressure test

When pressure is applied to the ocular bulb (until pain is felt ), the oculocardial reflex primarily leads to a reflex slowing of the pulse, a drop in blood pressure, deepening of breathing and induction of nausea. Initially, an increase in intracranial pressure on the way to the optic nerve sheaths was assumed to be the cause, but then the nervous reflex character was demonstrated in animal experiments.

The eyeball pressure test serves to demonstrate vegetative lability ( vagotonia ), but it can also be used therapeutically to interrupt paroxysmal tachycardias . The experiment can be carried out in different ways:

  • Finger pressure and placing weights, with pressure on the eyeball lasting 5 to 10 minutes, which should not exceed a weight load of 100 to 150 g.
  • One minute printing attempts with interruptions of 2 to 3 seconds.

Both types of experiment should not cause any damage to the retina . The oculocardial reflex can be triggered more frequently in people over 50 years of age.

The ocular weight load for experimental purposes is 105 g with normal intraocular pressure (15 mmHg ) and a brachial pressure of 120/80 mmHg and 238 g with normal intraocular pressure with arterial hypertension of 180/110 mmHg.

literature

  • B. Aschner: About a hitherto not yet described reflex from the eye to circulation and breathing. Radial pulse disappears when pressure is applied to the eye. Vienna Klin Wochenschr 21 (1908) 1529
  • G. Dagnini: Intorno ad un riflesso provocato in alcuni emiplegici collo stimolo della cornea e colla pressione sul bulbo oculare. Bull Sci Med (Bologna) 79 (1908) 380
  • EJ Wormer: Syndromes of Cardiology and their Creators. Munich 1989, pp. 1-5