Pupils Flashcards
The iris sphincter muscle encircles the pupil and _ the pupil which is known as _
Constricts, miosis
The iris dilator radial muscle _ the pupil which is known as _
Dilates, mydriasis
The sphincter muscle is innervated by the _ nervous system through _ with the neurotransmitter _
Parasympathetic, CNll , acetylcholine
The dilator muscle is innervated by the _ nervous system through _ with the neurotransmitter _ and _
Sympathetic , CNV , epinephrine, norepinephrine
Light traveling from the eye to the brain is called _ pathway and is responsible for the _ response
Afferent , direct
Light traveling from the brain to the iris sphincter is called the _ pathway and is responsible for the _ response which is equally distributed to each eye.
Efferent, consensual
The near reflex consists of _ , _ and _
Accommodation, covergence and pupil constriction
The afferent pupillary pathway
Ganglion cells in the retina Optic nerve Optic chiasm Optic tracts Pretectal nuclei in midbrain Posterior commissure crossing Edinger-westphal nuclei (part of CN3 nuclei )
Afferent pupillary defects can include
Large retinal lesion Optic nerve disease Optic nerve compression Optic tract lesion Midbrain lesion
Fibers along the surface of CN3 travel next to the _ and are exposed to forces of herniation
Posterior communicating artery
Efferent parasympathetic response pathway
Edinger Westphal nuclei Oculormotor CN3 Ciliary ganglion Short posterior ciliary nerves Choroid, iris sphincter and ciliary body
Efferent sympathetic response pathway
1. Order neuron Hypothalamus synapse C8-T2 in spinal cord 2. Order neuron Exit spinal cord Superior cervical ganglion 3. Order neuron CNV nasociliary branch Long ciliary nerves Dilator muscle, mueller muscle, and frontal sweat glands
When evaluating the pupils the patient should be directed to view a _ target at distance such as a small light. Pupil _ is generally measured in a _ room and should be _ in size
Non accommodation, size , dark , equal
Normal average pupil size ranges are in the light _ and in the dark _
2-4 mm , 4-8 mm
Patient with _ pupils after LASIK may have impaired night vision such as _, _, and _
Large, starburst, halos , ghost images
If a patient has anisocoria (unequal pupil size) the pupil should be measured in _
Light and dark
Pupil _ should be evaluated with normal being _ and _
Shape , round , centered
The pupil _ should be tested evaluating both the _ and _ response
Reaction to light , direct, consensual
Direct pupil response _
Constriction of the pupil light is shone
Consensual response _
Constriction of un-illuminated pupil
The swinging flashlight test is done to check an _ which is known as _
Relative afferent pupil (RAPD) Narcus -Gunn pupil
The pupils response to _ should also be measured and recorded if there is an abnormal light response
Accommodation
When a patient looks from a distance non accommodative target to near (20/40) accommodative target normal pupils with both _
Constrict
Afferent accommodate pathway is the same as the afferent _ pathway for image analysis
Visual
_ pathway differs from light pupillary pathway
Accommodative
Accommodative efferent pathway
Visual cortex, prefrontal cortex oculomotor nucleus and Edinger -westphal nucleus oculomotor nerve goes to medial rectus muscle (convergence part of the near reflex) Ciliary ganglion Short posterior ciliary nerves Iris sphincter and ciliary muscle
The accommodative pathway differs from the light pathway in that fibers skip the _ which is called _
Pretectal nucleus in midbrain , light near dissociation
The normal pupil response to light occurs when light is shone in one eye causes _ , equal constriction of _ pupils. Shine light in eye _.
Brisk(fast) , both, 2-3 sec
_ is spasmodic, rhythmic dilating and contracting pupillary movements which are usually normal
Hippus
Dilating drops simulate or inhibit receptor and have _ bottle tops.
Sympathetic stimulator _
Red, drives dilator muscle contraction
Drop: phenylephrine 2.5% -10% ( neosynephrine)
Parasympathetic inhibitor _
Prevents sphincter constricting
Drops: tropicamide 0.5-1% (mydriacyl)
Cyclopentolate, atropine , homatropine , scopolamine
_ is unequal pupil size between eye
Anisocoria
Localize anisocoria by pupil response
Asymmetry equal in light and dark
Physiologic or simple anisocoria
Asymmetry greater in dark
One pupil cannot dilate sympathetic nervous system defect
Asymmetry greater in light
One pupil cannot constrict parasympathetic (nervous system) defect
Anisocoria normal light reaction
Physiologic
Horner’s syndrome
Anisocoria abnormal light reaction
Adie’s tonic
3rd nerve palsy
Pharmacologic
Iris sphincter damage
Constricted pupil anomalies
Horner’s syndrome Argyll Robertson pupil Iritis Corneal irritation Pharmaceutical Street drugs
Horner’s syndrome is from lack of _ innervation, it’s signs including _ dilator muscle not being stimulated from SNS so Anisocoria worse in dark _ slight loss of lid elevation from muellers muscle not being stimulated from
SNS
Sympathetic, miosis , ptosis
_ loss of facial sweat from sweat glands not being stimulated from SNS
Anhydrosis
Pharmaceutical testing for Horner’s includes
_ prevents reuptake of norepinephrine from dilator muscle synapse flooding it. Normal eye will dilate and Horner’s eye does not dilate as the SNS block does not allow the release of norepinephrine in the first place.
Cocaine 10%
_ Normal eye does not change in size and horners eye will dilate with reduction of ptosis
Apraclonidine (0.5%) (iopidine)
_ stimulates intact SNS nerve to release norepinephrine to dilator muscle. I’d Horner’s eye dilates this rules out 3rd order neuron problem pointing to 1st and 2nd order neuron problem
Hydroxyamphetamine
Horner’s syndrome post ganglionic 3rd order neuron problems can include: ___ dissection (splitting apart) of blood within wall often from injury such as whiplash that can lead to stroke from carotid occlusion or clot. _ neck dissection _
Carotid artery damage, post surgical , cavernous sinus tumor
Horner’s 2nd order neuron lesion can include __ ( beware of Horner’s in smokers) __ sentinel nodes in neck __ aortic aneurysm, brachial plexus syndrome, surgery
Apical lung cancer , metastasis, check lesion
Horner’s 1st order neuron lesion can include: _
Brain and spinal cord-stroke , tumor
Congenital horner’s can be associated with _ or _
Retinoblastoma, heterochromia
Horner’s pupil responses are
Direct response in affected eye
Consensual response in affected eye
Increased accommodative response
__ is often from CNS syphilis and presents with bilateral pupil constriction unequal in size and irregular in shape. The pupils won’t dilate with atropine.
Argyll Robertson pupils
No direct response in affected eye
No consensual response in affected eye
Good accommodative response (light-near dissociation)
_ is inflammation that causes iris edema constricting the pupil
Iritis
_ from foreign body or trichiasis can construct the pupil
Corneal irritation
Constricting drop used for the treatment of _ can construct the pupil and include :
Glaucoma , pilocarpine , carbachol
Other substance that can constrict the pupils are
Alcohol
Opioids
A fixed non reactive pupil _
Can be very dangerous
Anisocoria worse in light is due to lack of _ innervation to sphincter muscle so pupil won’t constrict
Parasympathetic
aneurysm of the posterior communicating artery can compress the CN3 fibers causing the pupil to dilate, and if ruptures can cause _ or _
death or severe neurological damage
3rd ( oculomotor) nerve palsy signs can include
dilated pupil that has poor or no reaction directly or consensual or accommodative , ptosis
tropia- eye down & out
adies tonic pupil can be from
PNS lesion @ cilary ganglion or post viral more predominate in women 20-40
3rd nerve palsy can be from
slow contraction to light directly and consensually ( contracts in segments)
slow re-dilation
normal accomodative pupil contriction
pharmaceutical testing for adies pupil shows sensitivity to _ where _ constricts adies pupil but not normal pupil
acetylcholine , -pilocarphine .12%
mydriatics or cycloplegics
red top bottles
__ is a blind eye that is caused from defects in fibers in the ON proximal to the chiasm. The pupil responses of an amaurotic pupil reveak a total afferent pupillary defect (TAPD) versus a relative defect where some vision may be possible.
Amaurotic pupil no direct response if affected eye non consensual response in non-affected eye direct response in non -affected eye consenual response in affected eye
