PUPILS Dr. Canan Aslı Yıldırım Ophthalmology
PupillaryReactions • A three-neuron arc • Afferent neurons from retinal ganglion cells to pretectal area and to parasympathetic motor pool (Edinger–Westphal nucleus) of oculomotor nuclear complex • Efferent parasympatheticoutflow from oculomotor nerve to ciliary ganglion • Efferent nerves from ciliary ganglion to pupillary sphincter
Light Reflex Pathway • Optic chiasm: crossed to uncrossed fibers ~ 53:47. • Crossed fibers: from nasal retinal receptors of the contralateral eye • Uncrossed fibers: from temporal retinal receptors of the ipsilateral eye • Pregeniculate optic tract - pupillomotor branches of afferent axons gain access to pretectal nuclear area
Oculosympathetic Pathways A three neuron arc. The first neuron (Preganglionic) starts in the posterior hypothalamus and terminates in the ciliospinal center of Budge. The second neuron (Preganglionic) passes to the superior cervical ganglion. The third neuron (Postganglionic) joins the ophthalmic division of the trigeminal nerve to reach the ciliary body and the pupil dilator muscle via the nasociliary and long ciliary nerves.
Oculosympathetic Pathways Sympathetic outflow to the iris dilator muscles begins in the posterolateral area of the hypothalamus and descends uncrossed through the tegmentum of the midbrain and pons
Detection and Diagnosis of Pupillary Defects: • A semi-darkened room • Patient views a distant object • Round, equal in diameter • Anisocoria : reassespupils in varying illumination ! • Dim light & poorpupillarydilation: sympatheticsystemdysfunction • Brightlight & poorpupillaryconstriction: parasympatheticsystemdysfunction • Theswinging-flashlight test • MarcusGunnpupil (afferentpupillarydefect) • Opticnervelesion on theaffectedeye
Near ReflexandAccommodation (1) increased accommodation of the lens (2) convergence of the visual axes of the eyes (3) pupillary constriction. Near Reflex: • Patient views a distant target, then a near target. • Observe both eyes to confirm the responses are equal and symmetrical.
Afferent Pupillary Defect (APD): "Marcus GunnPupil" : Afferent Pupillary Defect (APD) "pupillary escape" An optic nerve conduction defect is present Both pupils dilate when the abnormal eye is stimulated Swinging Flashlight Test (foropticnervedisfunction) :Grading an APD In a darkened room, patient fixating a distance object5 complete cycles (10 sec total) ≈a grade 4, severe defect
The Swinging Light Test Normal Defective
Patient With Abnormal Pupils Bright Dim R.A.P.D. Swinging flashlight test in two patients with mydriasis on the side of orbital trauma.
Light-Near Dissociation The light reflex is absent or abnormal, the near response is intact • Argyll Robertson Syndrome • Holmes-Adie tonic pupil syndrome • Diabetes mellitus • Aberrantoculomotor nerve regeneration
How to Interpret the Findings • Pupillary disorders • Dilated pupil • Tonic pupil (Adie’s pupil) • Small pupil • Horner’s syndrome • Argyll Robertson pupil
Amaurotic pupil • «Blind eye»an optic nerve lesion, no light perceptionA.) Pupils are of equal size.B.) Neither pupil reacts when the defective eye is stimulated. C.) Both pupils react when the contralateral eye is stimulated. D.) Near reflex is normal.
Essential Anisocoria • Benign pupillary inequality, same in all lightening conditions • Anisocoria is not enhanced in dim lighting (no sympathetic disruption) in bright illumination (no parasympathetic disruption)
Dilated Pupil • Usually efferent defect + Head injury = third cranial nerve (oculomotor) compression by herniation of the tomporal lobe + Droopy lid + double vision = aneurysm • Holmes-Adie’s tonic pupil • Dilating eye drop
Tonic Pupil (Adie’s Pupil) • Healthy young women • Unilateral • Benign lesion in the ciliary ganglion • Denervation hypersensitivity (constriction with methacholine 2.5%, 0.125% pilocarpine) • Associated with diminished deep tendon reflexes
Holmes-Adie tonic pupil syndrome • Relative mydriasis in bright illumination • Poor to absent light reaction • Slow contraction to prolonged near effort • Slow redilation after near effort • Iris sphincter sector palsy • Segmental vermiform movements of iris border • Defective accommodation
Holmes-Adie tonic pupil syndrome Bright A 52-year-old woman with right tonic pupil (left) 1 year later involvement of the left pupil developed as well (right). Dim Convergence 0.125% pilocarpine
Disorders Associated with Tonic Pupil • Polyneuropathy • Idiopathic • Holmes-Adie syndrome • Ross syndrome • Riley-Day syndrome • Inflammation/Infection • Forme fruste familial dysautonomia • Herpes viruses • Sarcoidosis • Paraneoplastic polyneuropathies • Ischemia • Guillian-Barre syndrome • Giant cell arteritis • Polyarteritis nodosa • Sjogren's syndrome • Migraine • Syphilis • Orbital Trauma and Surgery
Pharmacologic Accidents – Fixed Dilated Pupil • Atropine (1%)30–40 min • Cyclopentolate (1%)15–60 min • Homatropine (2%)10–30 min • Tropicamide (1%)20–40 min • Scopolamine (0.25%)15–30 min • Phenylepherine (2.5%)15–60 min • Hydroxyamphetamine (1%)45–60 min • Cocaine (4%)40–60 min
Small Pupil • Ptosis of upper eyelid + small pupil = Horner’s Synd. • Unilateral • Congenital or acquired lesion of sympathetic pathways • Carotid dissection, carotid aneurysm, tumor • 4% cocaine (will not dilate desympathectomized pupil) • Hydroxyamphetamine drops (differentiation of preganglionic from postganglionic lesions)
Oculosympathetic Defects (Horner’s Syndrome) There is a total / partial interruption of the sympathetic pathway. • Miosis • Partial ptosis • Apparent enophthalmos • Diminished sweat, drier skin • Transient dilated conjunctival and facial vessels; facial flush; ocular hypotony; increased accommodation • Heterochromia: if congenital; rarely acquired adult cases
Argyll Robertson Pupils • Visual function grossly intact • Decreased pupillary light reaction • Intact near response • Miosis • Pupils irregular • Bilateral, symmetrical • Poor dilatation • Iris atrophy variable • Tertiary syphilis