tonic pupil


pupil

 (P) [pu´pil] the opening in the center of the iris through which light enters the eye; see also Plate 17.Adie's pupil tonic pupil.Argyll Robertson pupil one that is miotic and responds to accommodation effort, but not to light.fixed pupil a pupil that does not react either to light or on convergence, or in accommodation.Hutchinson's pupil one that is dilated while the other is not.tonic pupil a usually unilateral condition of the eye in which the affected pupil is larger than the other, responds to accommodation and convergence in a slow, delayed fashion, and reacts to light only after prolonged exposure to dark or light; see also adie's syndrome. Called also Adie's pupil.

ton·ic pu·pil

a general term for a pupil with delayed, slow, long-lasting contractions to light and to a near vision effort, often with light-near dissociation; due to denervation and aberrant reinnervation of the iris sphincter; seen in various autonomic neuropathies and in Adie syndrome.

ton·ic pu·pil

(ton'ik pyū'pil) A general term for a pupil with delayed, slow, long-lasting contractions to light and to a near vision effort, often with light-near dissociation; due to denervation and aberrant reinnervation of the iris sphincter; seen in various autonomic neuropathies and in Adie syndrome

pupil

(pu'pil) [L. pupilla, little doll (the reflection in the pupil)] PUPIL DILATIONThe contractile opening at the center of the iris of the eye. It is constricted when exposed to strong light and when the focus is on a near object; is dilated in the dark and when the focus is on a distant object. Average diameter is 4 to 5 mm. The pupils should be equal. See: pupilla; illustration

Differential Diagnosis

Constriction of the pupil occurs, for example, in bright light and after exposure to drugs such as morphine, pilocarpine, physostigmine, eserine, and other miotics.

Dilation of the pupil is most often observed after treatment with mydriatic drugs (such as atropine, scopolamine, or homatropine), but may also be caused by paralysis of cranial nerve III, intracranial masses or trauma, sympathetic nervous system stimulation, and other pupillary stimuli.

Adie pupil

See: Adie, William John

Argyll Robertson pupil

See: Argyll Robertson pupil

artificial pupil

A pupil made by iridectomy when the normal pupil is occluded.

bounding pupil

Rapid dilatation of a pupil, alternating with contraction.

Bumke pupil

Dilatation of the pupil owing to psychic stimulus.

cat's-eye pupil

A pupil that is narrow and slitlike.

cornpicker's pupils

Dilated pupils found in agricultural workers who are exposed to dust from jimsonweed. The dust contains stramonium, a mydriatic.

fixed pupil

A pupil that does not react to stimuli.

Gunn pupil

See: Gunn, Robert Marcus

keyhole pupil

A pupil with an artificial coloboma at the pupillary margin.

luetic pupil

Argyll Robertson pupil.

Marcus Gunn pupil

See: Gunn, Robert Marcus

pinhole pupil

A pupil of minute size; one excessively constricted; seen after use of miotics, in opium poisoning, and in certain brain disorders.

Robertson pupil

See: Argyll Robertson pupil

stiff pupil

Argyll Robertson pupil.

tonic pupil

Adie pupil