EFFECT OF CERTAIN CHEMICAL STIMULI ON THE CALIBER OF THE RETINAL BLOOD VESSELS

Abstract

It is a matter of considerable importance to inquire into the physiologic and pharmacologic reactions of the retinal blood vessels. As Mylius¹pointed out, these reactions are complicated, and the correlation of certain experimental findings with clinical therapy depends on a clear understanding of these responses. The primary concern of this study of the retinal blood vessels is with the underlying forces which produce vasodilatation. This assumes therapeutic importance, as the treatment for spasm²and closure of the central blood vessels relates to measures which will produce immediate vasodilatation. Of the chemical agents available, acetylcholine and the nitrites have been the drugs most frequently employed. In general, these drugs produce marked relaxation of the vascular musculature with an associated drop in the systemic blood pressure. The favorable influence of these therapeutic measures has been recorded repeatedly in the literature. Many of these accounts appear convincing, but within recent