The test should be evaluated thirty minutes after the instillation of the drops to ensure accuracy. The cocaine test is used to confirm or deny the presence of a Horner's syndrome. However, a positive cocaine test does not localize the lesion. Pholedrine and Paradrine act similarly by producing the forced release of endogenous norepinephrine from the presynaptic vesicles. If the third neuron is damaged, there will be no endogenous norepinephrine and the pupil will not dilate, thus indicating a postganglionic lesion.
Dilation indicates first or second order neuron lesion.
There is currently no method of topical testing to differentiate a first order preganglionic lesion from a second order preganglionic lesion. In general, the treatment for Horner's syndrome depends upon the cause. In many cases there is no treatment that improves or reverses the condition. Treatment in acquired cases is directed toward eradicating the disease that is producing the syndrome. Recognizing the signs and symptoms is tantamount to early diagnosis and expedient referrals to specialists.