Ординатура / Офтальмология / Английские материалы / Rapid Diagnosis in Ophthalmology Series Pediatric Ophthalmology and Strabismus_Strominger, Duker, Macsai_2007

Esodeviations Strabismus: • 10 SECTION

Pseudoesotropia

Key Facts

•With visual axis aligned, there is a false appearance of esotropia

•Common cause of infant referral to an ophthalmologist

Clinical Findings

•Flat, broad nasal bridge

•Prominent epicanthal folds

•Narrow interpupillary distance

•Normal corneal light reflex

•No movement on cover–uncover test

Ancillary Testing

•Cover testing

•Hirschberg or Krimsky light reflex test if unable to perform cover test

•Full ophthalmic examination including slit lamp and fundus

Differential Diagnosis

•Congenital esotropia

•Accommodative esotropia

•High AC : A ratio esotropia

•Divergence insufficiency

•Spasm of near reflex

•Consecutive esotropia

•Non-comitant strabismus, i.e.:

• Duane syndrome type 1 • sixth nerve palsy • ocular myasthenia gravis

• progressive external ophthalmoplegia • restrictive strabismus

Treatment

• None required

Prognosis

•With growth, epicanthal folds displace and the bridge of the nose becomes more prominent, decreasing the appearance of pseudoesotropia

Esodeviations Strabismus: • 10 SECTION

Congenital Esotropia

Key Facts

•Constant esotropia present before 6 months of age

•Often hereditary

•1–2% incidence

Clinical Findings

•Cross-fixation or alternate fixation common

•Usually equal visual acuity, although amblyopia may be present

•Esotropia typically >30 PD

•Full abduction unless secondary medial rectus restriction

•Associated latent nystagmus, inferior oblique over-action, and dissociated vertical deviation

Ancillary Testing

•Cover–uncover and alternate cover testing

•Hirschberg or Krimsky light reflex test if unable to perform cover test

•Stereopsis testing

•Intraoperative forced duction testing to rule out secondary medial rectus restriction

Differential Diagnosis

•Pseudoesotropia

•Accommodative esotropia

•High AC : A ratio esotropia

•Divergence insufficiency

•Spasm of near reflex

•Consecutive esotropia

•Non-comitant strabismus, i.e.:

• Duane syndrome type 1 • sixth nerve palsy • ocular myasthenia gravis

• progressive external ophthalmoplegia • restrictive strabismus

Treatment

•Treat significant refractive error and amblyopia if present with spectacles and occlusion therapy

•Surgery: align to within 8 PD of orthotropia

•Ability to develop stereopsis increases if performed before 1 year of age

•Bilateral medial rectus recessions

•Bilateral lateral rectus resections

•Uniocular medial rectus recession and lateral rectus resection

Prognosis

•Excellent visual prognosis if early surgery and compliant with amblyopia treatment

•Variable development of stereopsis

Fig. 10.2 Congenital esotropia. (From Taylor D, Hoyt CS 2005 Pediatric Ophthalmology and Strabismus, 3rd edn. Saunders, London.)

A B

Fig. 10.3 Cross-fixation in congenital esotropia (A) The left eye is fixing the target and the right eye is deviating inwards. (B) Fixation is reversed spontaneously. (From Taylor D, Hoyt CS 2005 Pediatric Ophthalmology and Strabismus, 3rd edn. Saunders, London.)

Esotropia Congenital

Esodeviations Strabismus: • 10 SECTION

Accommodative Esotropia

Key Facts

•Alternative name: refractive accommodative esotropia

•Accommodation from uncorrected hyperopia leads to excess convergence that overcomes fusional divergence

•Age of onset between 6 months and 7 years (average 2.5 years)

•Intermittent at onset then becoming constant

•Often hereditary

•Can be precipitated by illness or trauma

Clinical Findings

•Comitant esotropia typically 20–30 PD

•Average hyperopia of +4.00 D

•Amblyopia and reduced stereopsis may be present

•Diplopia may be present initially until image becomes suppressed

Ancillary Testing

•Cycloplegic retinoscopy with cyclopentolate or atropine drops necessary to determine full amount of hyperopia

•Cover–uncover and alternate cover testing

•Hirschberg or Krimsky light reflex test if unable to perform cover test

•Stereopsis testing

Differential Diagnosis

•Pseudoesotropia

•Congenital esotropia

•High AC : A ratio esotropia

•Divergence insufficiency

•Spasm of near reflex

•Consecutive esotropia

•Non-comitant strabismus, i.e.:

• Duane syndrome type 1 • sixth nerve palsy • ocular myasthenia gravis

• progressive external ophthalmoplegia • restrictive strabismus

Treatment

•Fully correct hyperopic refractive error determined by cycloplegic retinoscopy with spectacles or contact lenses

•Child must wear glasses full time

•Anticholinesterase drops may be tried if non-compliant with glasses

•May cause iris cysts, and systemic absorption may interfere with general anesthesia

•Concomitant use of phenylephrine to help prevent cysts

•More susceptible to depolarizing agents because of lower pseudocholinesterase levels

•Occlusion therapy if amblyopia present

•Strabismus surgery may be required if residual esotropia despite hyperopia fully corrected and compliant with wearing spectacles

Prognosis

•Excellent visual prognosis if treated early and compliant with spectacles and occlusion therapy for amblyopia, if present

Fig. 10.4 Accommodative esotropia without glasses.

Fig. 10.5 Eyes straighten with hyperopic correction in accommodation esotropia.

Esotropia Accommodative

Esodeviations Strabismus: • 10 SECTION

High AC : A Ratio Esotropia

Key Facts

•Alternative name: non-refractive accommodative esotropia

•Esotropia develops because of abnormal relationship between accommodation and accommodative convergence (AC : A ratio)

•During near accommodation, excess convergence tonus leads to esotropia in setting of insufficient fusional divergence

Clinical Findings

•Esotropia greater at near than distance

•Esotropia reduced at near with a +3.00 D lens

•Distance refraction can be:

• hyperopic (average +2.25 D) • myopic • emmetropic

•Reduced near stereopsis

•Amblyopia may be present

Ancillary Testing

•Cycloplegic retinoscopy with cyclopentolate or atropine drops necessary to determine full amount of hyperopia

•Cover–uncover and alternate cover testing at both distance and near with accommodative target

•Remeasurement at near with full distance correction and additional +3.00 D correction

•Hirschberg or Krimsky light reflex test if unable to perform cover test

•Stereopsis testing

Differential Diagnosis

•Pseudoesotropia

•Congenital esotropia

•Accommodative esotropia

•Divergence insufficiency

•Spasm of near reflex

•Consecutive esotropia

•Non-comitant strabismus, i.e.:

• Duane syndrome type 1 • sixth nerve palsy • ocular myasthenia gravis

• progressive external ophthalmoplegia • restrictive strabismus

Treatment

•Fully correct refractive error determined by cycloplegic retinoscopy

•Prescribe bifocals: +2.50 to +3.00

•Depends on alignment at preferred near reading distance

•Child must wear glasses full time

•Anticholinesterase drops may be tried

•May cause iris cysts, and systemic absorption may interfere with general anesthesia

•Concomitant use of phenylephrine to help prevent cysts

•More susceptible to depolarizing agents because of lower pseudocholinesterase levels

•Occlusion therapy if amblyopia present

•Strabismus surgery controversial

•Monitor at least yearly, because bifocal reductions may be possible with advanced age

Prognosis

Esodeviations Strabismus: • 10 SECTION

Divergence Insufficiency Esotropia

Key Facts

•More common in adults

•Deviation worse at distance than near

•Reduced fusional divergence

•May be isolated or associated with underlying neurologic abnormality:

• head trauma • Parkinson disease • pontine lesion

•May complain of diplopia at distance

Clinical Findings

•Comitant esotropia greater at distance than near

•Full abduction

Ancillary Testing

•Cover–uncover and alternate cover testing at both distance and near

•Maddox rod, Hirschberg, or Krimsky light reflex test if unable to perform cover test

•CT or MRI scan of brain with contrast

•Full neurologic evaluation

Differential Diagnosis

• Pseudoesotropia

•Congenital esotropia

•Accommodative esotropia

•High AC : A ratio esotropia

•Spasm of near reflex

•Consecutive esotropia

•Non-comitant strabismus, i.e.:

• Duane syndrome type 1 • sixth nerve palsy • ocular myasthenia gravis

• progressive external ophthalmoplegia • restrictive strabismus

Treatment

•Base out prisms in distance correction to alleviate diplopia

•Strabismus surgery may be required

•Treat underlying neurologic condition if present

Prognosis

•Isolated divergence insufficiency may resolve

•Depends on ability to treat underlying neurologic condition

Esodeviations Strabismus: • 10 SECTION

Spasm of the Near Reflex

Key Facts

•Abnormality of near response

•Usually functional

•May have underlying neurologic disease

Clinical Findings

•Esotropia with excessive accommodation and convergence

•Miosis

•Normal ductions with limited lateral gaze on version testing

•Myopic shift

Ancillary Testing

•Cover–uncover and alternate cover testing at both distance and near

•Hirschberg or Krimsky light reflex test if unable to perform cover test

•Cycloplegic retinoscopy

•Neurologic evaluation

Differential Diagnosis

• Pseudoesotropia

•Congenital esotropia

•Accommodative esotropia

•High AC : A ratio esotropia

•Divergence insufficiency

•Consecutive esotropia

•Non-comitant strabismus, i.e.:

• Duane syndrome type 1 • sixth nerve palsy • ocular myasthenia gravis

• progressive external ophthalmoplegia • restrictive strabismus

Treatment

•Fully correct any hyperopia

•Consider bifocals

•Cycloplegic agents: homatropine or atropine

•Treat underlying neurologic condition if present

Prognosis

•Problematic

•Depends on ability to treat underlying neurologic condition