Incorrect

Correct! A lesion of the ciliary ganglion in the orbit interrupts the parasympathetic supply to the iris sphincter and ciliary muscle, creating a pupil that does not constrict to light or to a target viewed at close range. Within weeks, pupil constriction to a target viewed at close range (“the near response”) is reestablished, but that constriction occurs slowly, creating the term “tonic pupil.” When gaze is redirected from a near to a distant target, pupil dilation is also slow. You might also note that the affected pupil is slightly oval and that the tonic constriction is segmental. Why do those phenomena occur? Because a lesion of the ciliary ganglion affects its nerve outflow segmentally; that is, one part of the iris sphincter is damaged more than other parts. Query: if you are confronted with a unilaterally dilated pupil, how would you know that it might be caused by a relatively acute ciliary ganglionopathy (before development of light-near dissociation and tonic features) rather than by exposure to a topical parasympatholytic agent? There are two clues: 1) in the short term, ciliary denervation causes asymmetric enlargement of the pupil (it has an oval shape) because the denervation is segmental, whereas parasympatholytic agents cause symmetric enlargement of the pupil (it has a round shape); and 2) a ciliary denervated pupil will constrict following instillation of pilocarpine 1%, whereas a pupil that is dilated because of topical exposure to a parasympatholytic agent will constrict minimally after instillation of pilocarpine 1%. Finally, here is a comment about the other answer choices. The combination of ptosis and supraduction deficit could represent a lesion of the superior division of the somatic portion of the third cranial nerve, which would occur intracranially, not in the orbit. The combination of ptosis and miosis suggests Horner syndrome, which arises from a lesion of the oculosympathetic pathway, which does not include the ciliary ganglion. The combination of mydriasis, adduction deficit, and lack of constriction to light or a near target is suggestive of a lesion of the intracranial third nerve that affects its inferior division.

Incorrect