The effect of local anaesthetics upon the conjunctivitis caused by mustard oil

Abstract

Spiess 1 and Ninian Bruce 2 have shown that the oedema of the conjunctiva which can be produced by instilling mustard oil into the conjunctival sac of a rabbit, can be prevented by the instillation of 10 per cent. cocaine. Bruce interprets this action as being due to the inhibition of vasdilator axon reflexes to the capillaries and smaller arterioles, and he found that if the ophthalmic nerve was cut before applying mustard oil oedema could then be produced only during the period in which the vasodilator fibers were still undegenerated, and a sufficient time were allowed for the vasodilator nerves to degenerate completely before the mustard oil was applied, oedema did not result after the instillation of mustard oil. Bruce's results have been confirmed by Bardy. 1

In 1917 I 2 was able to demonstrate the following facts : (1) That the application of epinephrin, producing a local vaso constriction of the conjunctival vessels, inhibited the development of the oedema, for about an hour, but that after the epinephrin effect had worn off oeclema developed subsequently. (2) That any continued lowering of the general blood pressure to less than 50 mm. Hg. prevented or greatly retarded the development of the oedema, even if the conjunctival vessels were dilated by the local administration of 1 per cent. sodium nitrite or if lymph secretion were increased by the intravenous injection of “Witte's peptone.” (3) That intravenous lowering of the general blood pressure by the continuous intravenous injection of dilute hydrochloric acid, in spite of the acidosis produced, diminished or entirely prevented the development of the oedema from mustard oil. (4) That ligation of the carotid artery greatly reduced the development of oedema in the eye upon the side corresponding to the ligated artery; and that in the peripheral end of the ligated artery the blood pressure was less than 40 mm. Hg.