in Children



Round pupils that differ in size by 0.5 mm or more



• 15–30% (physiologic)

• Other causes rare


• Physiologic: None

• Trauma (including intraocular or brain surgery)

• Iritis

• Meningitis

• Topical contact with mydriatic or miotic (drop, ointment or plant)

• Paraspinal neuroblastoma

• Birth trauma

• Family history of anterior segment dysgenesis


• Physiologic not genetic:

– Anterior segment dysgenesis may be due to a genetic disorder.


• Physiologic: None

• Genetic counseling for anterior segment dysgeneses

• Avoidance of contact with mydriatics and miotics

• Careful follow-up screening for patients at risk for iritis (e.g., juvenile idiopathic arthritis) to detect inflammation early


• Maldevelopment or dysfunction of the pupillary dilator or sphincter muscle or

• Mechanical impairment of the pupil (e.g., posterior synechia) or

• Idiopathic (physiologic)


• Physiologic/idiopathic (most common)

• Congenital Horner syndrome:

• Birth trauma including brachial plexus injury

• Neoplasm rare

• Acquired Horner syndrome


Can represent metastatic neuroblastoma:

• Congenital third cranial nerve palsy

• Acquired third cranial nerve palsy:

– Trauma (most common) – surgical or nonsurgical

– Meningitis

– Tumor

– Aneurysm:

Unlikely under age 14

• Traumatic mydriasis (sphincter tears)

• Posterior synechiae due to iritis

• Adie’s tonic pupil:

– Much less common in children than in young women

– Usually idiopathic

• Pharmacologic mydriasis:

– Usually cycloplegic (pharmaceutical or environmental)

• Congenital miosis

• Aniridia and other anterior segment dysgenesis


• None in physiologic anisocoria

• Neoplasm in 23% of pediatric Horner syndrome (1)


Note especially neuroblastoma metastatic to cervical sympathetic chain, which can be life threatening and requires urgent workup.

• Other neoplasms causing Horner syndrome in children include benign paraspinal neuroblastoma, rhabdomyosarcoma (2), Ewing sarcoma, and juvenile xanthogranuloma (1).

• Abnormalities of extraocular muscle function and strabismus in third cranial palsy



• Trauma:

– Nonocular:

– Birth trauma

– Surgical (neck or chest) or other postnatal trauma

– Ocular blunt trauma

– Intraocular surgery

• Age of onset:

– Review old photos

• Duration

• Ptosis:

– Horner syndrome (1–2 mm or less)

– Third cranial nerve palsy

• Anhidrosis/hypohidrosis:

– Seen in some but not all cases of Horner syndrome

• Contralateral facial flushing and ipsilateral hypohidrosis (Harlequin sign):

– Seen in some but not all cases of Horner syndrome in infants

• Longstanding iris heterochromia in congenital Horner and some anterior segment dysgenesis


• Acuity

• Normal in physiologic anisocoria

• May be decreased due to amblyopia in third nerve palsy and Adie’s

• Accommodative amplitudes/dynamic retinoscopy:

– May be decreased in third cranial nerve palsy and Adie’s tonic pupil)

• Pupils:

– Anisocoria greater in darkness (smaller pupil is abnormal):

– Physiologic anisocoria

– Horner syndrome

– Mechanical restriction

– Anisocoria greater in light (larger pupil is abnormal):

– Third cranial nerve palsy

– Adie’s pupil

– Traumatic mydriasis

– Pharmacologic mydriasis

– Dilation lag of smaller pupil:

– Horner syndrome

– Light-near dissociation:

– Adie’s tonic pupil

– Segmental constriction:

– Adie’s tonic pupil

– Relative difference in pupil size preserved in dim and bright illumination: Physiologic anisocoria

– Iris heterochromia (lighter iris ipsilateral to smaller pupil):

Congenital Horner syndrome

• Eyelids:

– 1–2 mm (but not more) of upper eyelid ptosis in Horner syndrome, ipsilateral to the smaller pupil

– More profound ptosis in third nerve palsy, ipsilateral to the larger pupil

– “Inverse ptosis” (slight elevation of the lower lid of the eye with the small pupil) with Horner syndrome)

• Motility:

– Normal with all causes of anisocoria except third nerve palsy

– Limitation of elevation, depression, and adduction in third nerve palsy:

The palsied eye is typically “down and out” (exotropic and hypotropic)

• Palpate abdomen and supraclavicular region looking for neuroblastoma or other neoplasm



• If suspect Horner, with no clear evidence of birth injury: Spot urine for vanillylmandelic acid (VMA) and homovanillic acid (HVA)

• Note: Urine testing may not be as sensitive as imaging (1)[C] in diagnosing neuroblastoma


• MRI (with and without gadolinium) of the brain, neck, chest, and upper abdomen if suspect Horner syndrome unless clear evidence of birth trauma (1)[C]:

– Some recent evidence (3)[C] questions the need for extensive evaluation of patients with Horner syndrome.

• MRI of brain with MRA if suspect third cranial palsy and no clear etiology

Diagnostic Procedures/Other

• Review old photographs to help determine whether anisocoria is congenital or acquired

• Pharmacologic testing for Horner syndrome:

– Cocaine 5% drops dilate the normal pupil but not the Horner pupil.

– Apraclonidine 0.5% produces reversal of anisocoria in 30–60 min in Horner syndrome.

– Effect easier to see in bright than in dim light (4)[C]

– Hydroxyamphetamine 1% dilates preganglionic but not postganglionic Horner pupil.

• Pharmacologic testing for Adie’s tonic pupil: Pilocarpine 0.125% constricts Adie’s pupil but not a normal pupil or a pharmacologically dilated pupil.



• For Adie’s tonic pupil: Pilocarpine 0.125% b.i.d.–q.i.d. can be used for cosmesis and to aid accommodation.

• For posterior synechiae due to iritis: Pharmacologic mydriasis (such as atropine 1% drops) to break the synechiae, in addition to topical steroid treatment (with systemic medication as indicated) for the iritis.

• Anisocoria due to other causes is not treated; instead, an underlying cause is identified and treatable.


General Measures

• Amblyopia (most likely with third nerve palsy and Adie’s) is treated with refractive correction if needed, and patching or atropine penalization.

• Cosmetic contact lens is used if concerns about appearance in older children.

Issues for Referral

• Patients discovered to have evidence of a neoplasm should be referred without delay to appropriate specialists (oncology, neurosurgery).

• Patients below 12 months of age with Adie’s tonic pupil should be referred to pediatric neurology to rule out familial dysautonomia.



• Physiologic: None needed

• Third nerve palsy and Adie’s: Follow-up to rule out amblyopia

• Possible Horner syndrome with equivocal clinical and/or pharmacologic findings: Re-examine in 3–6 months, consider repeat urine testing

• Follow-up for glaucoma in anterior segment dysgeneses

• Follow-up for other causes of anisocoria is determined by the underlying cause.


• Reassure parent that anisocoria itself does not affect acuity or visual development (except if accommodation impaired in Aides or third cranial palsy).

• If Horner syndrome is suspected but not proven, instruct the parent to watch for development of ptosis and anhidrosis.


• Physiologic anisocoria: Excellent. No deficit is expected.

• Other causes: Prognosis depends on underlying cause.


1. Mahoney NR, Liu GT, Menacker SJ, et al. Pediatric Horner syndrome: Etiologies and roles of imaging and urine studies to detect neuroblastoma and other responsible mass lesions. Am J Ophthalmol 2006;142(4):651–659.

2. Jeffery AR, Ellis FJ, Repka MX, et al. Pediatric Horner syndrome. J AAPOS 1998; 2(3):159–167.

3. Smith SJ, Diehl N, Leavitt JA, et al. Incidence of pediatric Horner syndrome and neuroblastoma threat. Arch Ophthalmol 2010;128(3):324–329.

4. Chen PL, Hsiao CH, Chen JT, et al. Efficacy of apraclonidine 0.5% in the diagnosis of Horner syndrome in pediatric patients under low or high illumination. Am J Ophthalmol 2006;142(3):469–474.

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Nov 9, 2016 | Posted by in OPHTHALMOLOGY | Comments Off on in Children

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