All patients with bilateral tonic pupils should be considered for serologic testing for syphilis. It is important to check patient history for diabetes mellitus, trauma, and other neurologic diseases. Additionally, the pupils will demonstrate poor dilation after mydriatic eyedrop administration. 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. This light-near dissociation is bilateral in 80-90% of patients, but both pupillary size and degree of light-near dissociation can be asymmetric. However, there is brisk pupillary constriction for accommodation to near targets and brisk redilation after the near reaction, which distinguishes AR pupils from Adie tonic pupils. The pupils also demonstrate minimal or complete absence of pupillary constriction to light stimulation. Upon close examination, the pupils have an irregular shape (oval, egg-shaped, tear shaped, irregularly polygonal, serrated, or eccentric). Patients with AR pupils typically present with miotic pupils (<2mm in diameter) that do not dilate fully in dim light. CausesĪlthough AR pupils are classically associated with neurosyphilis, other AR like pupils can occur in the setting of diabetes mellitus, neurosarcoidosis, chronic alcoholism, encephalitis, multiple sclerosis, Lyme disease, or herpes zoster. During this period, the pupillary light reactions progress from slow, incomplete constrictions to complete loss of the light reflex. The damaging lesion in AR pupils usually develops over a period of time, sometimes asymmetrically and sometimes at an uneven rate. When this inhibitory pathway is disrupted, parasympathetic neurons of the Edinger-Westphal nucleus that naturally fire at a high rate can lead to sustained pupil contraction by the iris sphincter and cause miosis in AR pupils. Supranuclear adrenergic fibers that inhibit the Edinger-Westphal nucleus are necessary for iris sphincter relaxation and pupil dilation. However, the more ventrally located fibers of the Edinger-Westphal nuclei that control the near reaction are spared. Specifically, a lesion of the dorsal aspect of the Edinger-Westphal nucleus can interrupt the pretectal oculomotor light reflex fibers. Bilateral tonic pupils are more frequently to be encountered than AR pupils in the modern era.ĭamage to the rostral midbrain can result in AR pupils. As the prevalence of syphilis has decreased to 2.1 per 100,000 population in the year 2000, the percentage of non-syphilitic AR pupil findings have increased. However, with the efficacy of penicillin therapy, the incidence of tertiary syphilis has decreased, and AR pupils have become quite rare in the United States. EpidemiologyĪR pupils were originally described with neurosyphilis and the finding became a characteristic clinical sign for the disease. Douglas Moray Cooper Lamb Argyll Robertson, a Scottish ophthalmologist and surgeon, originally described this abnormal pupil finding in 1868. In addition, AR pupils are accompanied with frequent iris atrophy. The characteristic light-near dissociation of AR pupils occurs most often bilaterally but may be unilateral in some patients. The pupils are noticeably able to accommodate to near targets, with subsequent normal and brisk redilation to far. The affected pupils initially appear small, and are irregular, but as opposed to the tonic pupil do not maintain increased tone to near targets. Argyll Robertson (AR) pupils, are characterized by small and irregular pupils that have little to no constriction to light but constricts briskly to near targets (light-near dissociation).
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