![]() ![]() It explains the defining features of a tonic pupil: Loewenfeld’s theory is now generally accepted. This means that every time the patient accommodates her gaze to a near object, some of the innervation to the ciliary muscle will spill over into the iris and constrict the pupil. There will be plenty of accommodative neurons re-growing into the iris sphincter, and it won’t take very many of them to make a little muscle like the iris sphincter contract. The other way around, it is a different story. But there will not be enough of them to budge that big muscle, so there will be no detectable accommodation with exposure to light. Some parasympathetic light-reaction neurons that were originally destined for the iris sphincter will end up innervating the ciliary muscle. In her own words: Let’s say that in a given fresh Adie’s pupil, a random 70% of the cells in the ciliary ganglion stop working and that, in a couple of months, these neurons re-grow and randomly re-innervate both intraocular sphincters (the ciliary muscle and the iris sphincter). She noted that pathological destruction of nerve cells in the ciliary ganglion that is found in all cases of Adie pupil. Based on these observations, Loewenfeld proposed an explanation of the tonic pupil. The ciliary muscle is also more massive than the constrictor pupillae, again by a factor of twenty. The ciliary ganglion contain many more nerve fibers directed to the ciliary muscle than nerve fibers directed to the constrictor pupillae – roughly twenty times more. The strange behavior of tonic pupils was first explained by Irene Loewenfeld in 1979. A person with anisocoria (one pupil bigger than the other) whose pupil does not react to light (does not constrict when exposed to bright light) most likely has Adie syndrome – idiopathic degeneration of the ciliary ganglion. Tonic pupils are fairly common – they are seen in roughly 1 out of every 500 people. When the person focuses on a more distant object (say the far side of the room), the pupil (which would normally dilate immediately) remains constricted for several minutes, and then slowly dilates back to the expected size. On close inspection, the constricted pupil is not perfectly round. When a person with an Adie pupil attempts to focus on a nearby object, the pupil (which would normally constrict rapidly) constricts slowly. These neurons project axons through the short ciliary nerves to innervate the ciliary muscle and pupillary sphincter muscle.Įxiting from the anterior surface of the ciliary ganglion are the short ciliary nerves which contain the sensory, postganglionic sympathetic and postganglionic parasympathetic axons to the eye.Ĭlinical significance Adie tonic pupil ĭiseases of the ciliary ganglion produce a "tonic pupil", which is a pupil that does not react to light (it is “fixed”) and has an abnormally slow and prolonged response to attempted near vision ( accommodation). Within the ganglion the axons synapse onto the postganglionic parasympathetic neurons. The parasympathetic root branches from the inferior division of the oculomotor nerve and carries the preganglionic parasympathetic axons from the Edinger-Westphal nucleus to the ciliary ganglion.Sometimes, they also supply the pupillary dilator muscle, however these axons usually travel from the nasociliary nerve to the long ciliary nerves to enter the eye. The sympathetic root contains the postganglionic sympathetic axons that provide sympathetic supply to the blood vessels of the eye. The axons pass through the ganglion and enter the eye without synapsing into the short ciliary nerves. The sympathetic root originates from the internal carotid plexus with cell bodies in the superior cervical ganglion.These sensory axons supply the cornea, ciliary body and iris. The sensory root branches from the nasociliary nerve and travels through the ganglion forming part of the short ciliary nerves.The entering axons are arranged into three roots which join enter the posterior surface of the ganglion: Three types of axons enter the ciliary ganglion but only the preganglionic parasympathetic axons synapse there. Adie syndrome.Main article: Roots of the ciliary ganglion National Organization for Rare Disorders. Parasympathetic innervation to the head and neck. Overview of the anatomy, physiology, and pharmacology of the autonomic nervous system. Anatomical variations of the ciliary ganglion with an emphasis on the location in the orbit. Walsh and Hoyt's clinical neuro-ophthalmology, 6th ed. Lippincott Williams & Wilkins 2005:673-674. Kardon R. Chapter 14: Anatomy and physiology of the autonomic nervous system. In: Miller NR, Newman NJ, Biousse V, Kerrison JB, eds. Anatomical study of the roots of cranial parasympathetic ganglia: a contribution to medical education. Lovasova K, Sulla IJ, Bolekova A, Sulla I, Kluchova D. ![]()
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