![]() Argyll Robertson pupils have four characteristic findings: (1) bilateral involvement, (2) small pupils that fail to dilate fully in dim light, (3) no light reaction, and (4) brisk constriction to near vision and brisk redilation to far vision. What is the mechanism of light-near dissociation due to Argyll Robertson pupils The distinction between the light-reflex and near-reflex pathways forms the basis for some forms of pupillary light-near dissociation (i.e., pupils that do not react to light but react to near stimuli) in which the dorsal midbrain and pretectal nuclei are damaged. Slit lamp examination often shows portions iris atrophy along with transillumination defects. Over time, AR pupils eventually lose their near constriction as well and become miotic and immobile. The pupils are not necessarily fixed to light, though they become. The cardinal features are summarised in table 3. The definition should be strict otherwise a whole host of pupillary abnormalities with some degree of light-near dissociation will be so designated. This process is experimental and the keywords may be updated as the learning algorithm improves. How is Argyll Robertson pupil diagnosed A. This light-near dissociation is bilateral in 80-90 of patients, but both pupillary size and degree of light-near dissociation can be asymmetric. ARGYLL ROBERTSON PUPIL Argyll Robertson described his pupillary syndrome in 1869. These keywords were added by machine and not by the authors. This specific diagnostic term is Argyll Robertson Pupil. A lesion of the dorsal midbrain can result in light-near dissociation by compressing and interrupting the more dorsally located fibers of the light reflex pathway and sparing the more. There is absent or diminished light reflex due to the reduced light impulses being carried to the pretectal nucleus however, these patients often retain the ability to determine object distance and have an intact near reflex. Severe loss of afferent light input to both eyes, such as a bilateral optic neuropathy, is a common cause of light-near dissociation. Light-near dissociation is a pathologic finding with several possible etiologies including severe loss of afferent light input to both eyes, a lesion of the dorsal midbrain, tonic pupils, aberrant reinnervation of the third nerve or ciliary ganglion fibers, and Argyll Robertson pupils.
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