Densitometric control of retinal vascular reactions after mandibular nerve anesthesia

In a group of 44 patients, fundus photographs were taken before and after mandibular nerve anesthesia and examined by densitometry. These patients were divided into subgroups receiving 4 cm3 of Xylocitin 2% alone or in combination with 0.005% norepinephrine, or 0.00125 or 0.002% epinephrine. In the presence of epinephrine, the retinal arterioles reacted with a temporary age-dependent narrowing. A placebo group received normal saline or had just the needle inserted. With one interesting exception, the reactions were minimal. The cause of this reaction is a multifactorial one. In the first period, vagovagal reflexes are important; in the later phase, processes comparable to autoregulation play the main role.