Swinging flash-light test (examiner facing patient). This is found in optic neuropathy, retinopathy, Adie’ tonic pupil, Argyll Robertson pupil, Parinaud’ dorsal midbrain syndrome, aberrant regeneration of the third nerve, and diabetes.įigure 19-1. In light-near dissociation (LND) of pupils, there is better pupillary response to near stimuli than to light stimuli.Third-nerve palsy-Dilated pupil accompanied by ptosis and extraocular muscle palsies.Anhidrosis will be present if the lesion involves the sympathetic pathway proximal to the bifurcation of the common carotid artery. Horner’ syndrome-Miotic pupil accompanied by ptosis and possibly anhidrosis.Pharmacologic pupil-Either miotic or dilated pupil that does not respond to any pharmacologic testing.Argyll Robertson pupil-The miotic pupils are irregular and do not respond to light with poor dilation in the dark yet good near response.Adie’ tonic pupil-The affected pupil is larger and reacts poorly to light or near stimuli.Anisocoria-Pupillary size difference that may vary between light and dark.With RAPD, there will be a positive swinging flashlight test (Fig.Patients with anisocoria are often asymptomatic or may complain of other symptoms, such as droopy eyelid, blurred vision, focusing problems, or diplopia, depending on any accompanying symptoms. Patients with a RAPD will complain of vision and color loss in the affected eye. Symptoms and signs will vary according to the underlying etiology. Physiologic anisocoria is present when the pupil size difference remains the same in both bright light and in darkness. Constricted pupils can occur with iritis, pharmacologic blockade, Horner’ syndrome, Argyll Robertson pupil, or long-standing Adie’ pupil. The etiology depends on whether the abnormal pupil is the dilated or constricted pupil.ĭilated pupils can occur from iris sphincter trauma, Adie’ tonic pupil, third-nerve palsy, or pharmacologic blockade. Any disruption of the neural pathway or iris architecture will lead to abnormalities of the pupillary state.Ī relative afferent pupillary deficit (RAPD) or Marcus Gunn pupil will result from a significant unilateral or asymmetric visual deficit caused by retinal or optic nerve disease (optic neuropathy).Īnisocoria is the state where the two pupils are unequal in size. This equality in pupil size is a result of the bilateral symmetrical afferent input to the Edinger-Westphal complex in the midbrain and because of the symmetrical output of the paired sympathetic nuclei in the hypothalamus. Normal pupils are 3 to 4 mm in diameter in ambient light and are relatively equal in size. Pupil size reflects the neural input of both the sympathetic and parasympathetic systems on the dilator and sphincter muscles, respectively, of the iris.
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