II. Anatomy
- See Pupil Constriction (Miosis) for Neuroanatomy of Pupil Constriction
- Variable sized circular hole in pigmented iris
- Images
- Pupil "Hole" or aperture size controlled by 2 Muscles
- Sphincter pupillae
- Circular Muscle constricts pupil (Miosis)
- Parasympathetic fibers on CN3 from Edinger-Westphal Nucleus innervate the ciliary Ganglion
- Dilator pupillae
- Radial Muscle dilates pupil (Mydriasis)
- Sympathetic inputs via:
- Hypothalamus
- Ciliospinal center of Budge and Waller
- Sphincter pupillae
III. Physiology
- Pupil is analogous to a camera aperture
- Shutter aperture decreases in size under bright light conditions and for sharper focus
- Pupil constricts under bright light and with near focus (e.g. reading) known as accomodation
-
Optic Nerve (CN 2)
- Transmits visual signals not only to the visual cortex
- Transmits signals via a reflex loop to the pretectal nucleus
- Signals then travel onto the Edinger-Westphal Nucleus on each side of the Midbrain
- Shining light in one eye will result in a signal to both Edinger-Westphal Nucleii
- Signals are then transmitted to the ciliary Ganglion and along the course of Oculomotor Nerve
-
Oculomotor Nerve (CN 3)
- Innervates ciliary Muscle (iris constrictor), resulting in Pupil Constriction
- Accomodation (near Vision) also results in signals to the Edinger-Westphal Nucleus
- However those signals arise from the visual cortex
- Syphilitic Pupil (Argyll-Robertson Pupil, Prostitute's Pupil)
- Affected pupil does not react
- Lesion in the Midbrain blocks signals from the pretecal nucleus
- Syphilitic Pupil does accomodate
- Signals follow a different pathway from the visual cortex
- Affected pupil does not react
- Brainstem Herniation
- . Oculomotor Nerve (CN 3) is easily compressed
- Results in a dilated pupil that does not react (Blown Pupil)
- Parasympathetic fibers from the Edinger-Westphal Nucleus to the ciliary Muscle
- Found on the outside of the Oculomotor Nerve (CN 3),
- Parasympathetic fibers are first to be injured when CN 3 is compressed
IV. Findings
- Pupil Normal in
- Pupil size changes
- Pupil distortion
- Posterior synechiae
- Inflammatory adhesion between lens and iris
- Tear drop-shaped pupil
- Suggests Globe Rupture with iris prolapse
- Posterior synechiae
- Pupil fixed, mid-dilated, slightly irregular
- Acute Glaucoma
- Absent Pupillary Light Reflex
- Structural lesion
- Hypothermia
- Barbiturate or Opiate Overdose
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Related Studies
| Definition (MSH) | Conditions which affect the structure or function of the pupil of the eye, including disorders of innervation to the pupillary constrictor or dilator muscles, and disorders of pupillary reflexes. |
| Concepts | Disease or Syndrome (T047) |
| MSH | D011681 |
| SnomedCT | 68633000 |
| Italian | Disturbo pupillare, Disturbo pupillare NAS, Disturbi pupillari, Disturbi della pupilla |
| Dutch | pupilafwijking NAO, pupilaandoeningen, pupilafwijking, Pupilstoornis, Pupilstoornissen, Stoornis, pupil-, Stoornissen, pupil- |
| French | Anomalie des pupilles SAI, Trouble pupillaire, Troubles pupillaires |
| German | Pupillenstoerung NNB, Erkrankungen der Pupille, Pupillenstoerung, Störungen der Pupille |
| Portuguese | Alteração pupilar NE, Distúrbios da Pupila, Transtornos da Pupila, Transtornos Pupilares, Alterações da pupila, Anomalia pupilar, Distúrbios Pupilares |
| Spanish | Trastorno pupilar NEOM, trastorno pupilar (trastorno), trastorno pupilar, Trastornos de la pupila, Alteración pupilar, Trastornos de la Pupila |
| Japanese | 瞳孔障害ＮＯＳ, ﾄﾞｳｺｳｼｮｳｶﾞｲ, ﾄﾞｳｺｳｼｮｳｶﾞｲNOS, 遠心性瞳孔反応欠如, 異常瞳孔反応, 瞳孔反応-異常, 求心性瞳孔反応欠如, 瞳孔反応欠如, マ-カス-ガン瞳孔, 瞳孔機能異常, マ-カス･ガン瞳孔, 瞳孔障害, Marcus-Gunn瞳孔 |
| Swedish | Pupillstörningar |
| English | PUPILLARY DIS, PUPIL DIS, Pupil disorders, Pupillary disorder NOS, Pupil Disorder, Pupillary Disorder, Pupillary Disorders, Pupil Disorders [Disease/Finding], Pupillary disorder, Disorder of pupil, Pupillary disorder (disorder), Pupillary disorder, NOS, Pupil Disorders |
| Finnish | Mustuaisen sairaudet |
| Russian | ZRACHKA FUNKTSII NARUSHENIIA, ZRACHKA FUNKTSII ANOMAL'NYE, ЗРАЧКА ФУНКЦИИ АНОМАЛЬНЫЕ, ЗРАЧКА ФУНКЦИЙ НАРУШЕНИЯ |
| Czech | Poruchy zornice, Poruchy zornice NOS, Pupilární poruchy, poruchy zornic, pupila - poruchy, poruchy zornice |
| Croatian | Not Translated[Pupil Disorders] |
| Polish | Zaburzenia źreniczne, Odruchy źreniczne nieprawidłowe, Brak reakcji źrenic |
| Hungarian | Pupilla eltérés k.m.n., Pupilla betegségek, Pupillaeltérés |
| Norwegian | Pupillforstyrrelser |
