Ophthalmologic considerations: Dilation lag may occur in patients with a defect in the sympathetic innervation of the pupil, such as in Horner syndrome. The sympathetic preganglionic neurons in the lateral horn segments send fibers to end on the sympathetic neurons in the superior cervical ganglion, which sends sympathetic postganglionic axons via the long ciliary nerve to the iris dilator muscle. Pathway: In response to dark, the retina and optic tract fibers send signals to neurons in the hypothalamus, which then descend on the spinal cord lateral horn segments T1-T3. Pupillary escape can occur on the side of a diseased optic nerve or retina, most often in patients with a central field defect.Ī Horner syndrome pupil will show dilation lag “Pupillary escape” is an abnormal pupillary response to a bright light, in which the pupil initially constricts to light and then slowly redilates to its original size. A transient RAPD can occur secondary to local anesthesia. An RAPD can occur due to downstream lesions in the pupillary light reflex pathway (such as in the optic tract or pretectal nuclei). Alternatively, if the reactive pupil constricts more with the consensual response than with the direct response, then the RAPD is in the reactive pupil. If the reactive pupil constricts more with the direct response than with the consensual response, then the RAPD is in the unreactive pupil. Direct and consensual responses should be compared in the reactive pupil. Detection of an RAPD requires two eyes but only one functioning pupil if the second pupil is unable to constrict, such as due to a third nerve palsy, a “reverse RAPD” test can be performed using the swinging flashlight test. When the examiner swings the light to the unaffected eye, both pupils constrict. In patients with an RAPD, when light is shined in the affected eye, there will be dilation of both pupils due to an abnormal afferent arm. Ophthalmologic considerations: Testing of the pupillary light reflex is useful to identify a relative afferent pupillary defect (RAPD) due to asymmetric afferent output from a lesion anywhere along the afferent pupillary pathway as described above. Due to innervation of the bilateral E-W nuclei, a direct and consensual pupillary response is produced. From the E-W nucleus, efferent pupillary parasympathetic preganglionic fibers travel on the oculomotor nerve to synapse in the ciliary ganglion, which sends parasympathetic postganglionic axons in the short ciliary nerve to innervate the iris sphincter smooth muscle via M3 muscarinic receptors. Pathway: Afferent pupillary fibers start at the retinal ganglion cell layer and then travel through the optic nerve, optic chiasm, and optic tract, join the brachium of the superior colliculus, and travel to the pretectal area of the midbrain, which sends fibers bilaterally to the efferent Edinger-Westphal nuclei of the oculomotor complex. Pupillary constriction occurs via innervation of the iris sphincter muscle, which is controlled by the parasympathetic system. "Right Before Your Eyes" was most popular in the Philippines during its release in 1982.The pupillary light reflex is an autonomic reflex that constricts the pupil in response to light, thereby adjusting the amount of light that reaches the retina. It reached 22 on the Contemporary Adult chart in Canada. The America version of "Right Before Your Eyes" was issued as that album's second single – following up America's Top Ten single " You Can Do Magic" – and rose to #45 on the Billboard Hot 100: the track's Adult Contemporary chart peak was #16. It was also recorded by America for their 1982 album View from the Ground. " Right Before Your Eyes" (popularly known as " Rudolph Valentino") is a song written by Ian Thomas and introduced on his 1977 album Goodnight Mrs.
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