Esodeviations

 

Can be totally benign (esophoria) and serious disease (CN VI palsy)

 

can be true pediatric ophthalmic emergency

 

Most important historical feature?

age of onset!

 

2 major categories:

infantile or congenital vs. accommodative

 

infantile ET: onset before 6 months, fusion is usually bad (usually reason for ET)

accommodative et: onset after 6 months (usually 2 years), fusion usually good, true emergency

 

INFANTILE ET

•presents before 6 mo of age

incidence prolly <.5%

•etiology controversial: primary congenital absence of cortical fusion (Worth), or primary motor misalignment with absence of fusion secondary

•treatment implications (early vs. late)

•usually large angle deviation

•usually constant

•full abduction (dolls head) - check for muscle movement

•cross fixation

•alternates fixation

•amblyopia reduced by cross fixation

•refraction error similar to age-matched population

•assoc motor abnormalities: oblique muscle dysfunction, latent nystagmus, dissoc strabismus complex, smooth pursuit asymmetry

•usually isolated

•but some systemic assocs: downs, cp, albinism

•some inheritance

 

ASSESSMENT:

•check fixation preference

•assess ductions: dolls head, abduction saccades (optikinetic drum)

•measure deviation: prism cover, krimsky, hershberg

 

TREATMENT:

•if small (<40 PD) and intermittent over half will resolve spontaneously (CEOStudy) by 6 months

•if large (>40) and <+3.0 D very few resolve

•correct hyperopia > 3D

•amblyopia management

 

Surgery

early: 12-13 weeks of age if >40 PD, two exams 3-4 weeks apart

traditional: treat amblyopia first, surgery b/w 6-24 mo

BMR

R and R

Post-op: watch for fixation preference, maintain alignment within 10 PD of ortho

•monofixation syndrome is desired outcome (can have peripheral fusion, but have central suppression of one eye)

•residual esotropia: check and correct hyperopia, re-operate

•consecutive exotropia: BLR or advance MR

 

ACCOMMODATIVE ET

•onset usually after 2

•usu presents as an intermittent ET

•angle is often small

•fusion often NORMAL=EMERGENCY, have to correct before loses fixation

 

types

•refractive: crossing assoc with hyperopia

•high accom convergence/accom: crossing at near, hyperopic, myopic or emmetropic

 

ASSESSMENT

•fixation preference

•rule out abduction deficit

•cycloplegic refraction: cyclogel, atropine

TREATMENT

•give free cycloplegic refraction

•glasses must be worn full time

•to improve acceptance: cut the plus, atropine

•bifocal

•surgery: not for purely accommodative et, ok for partially accommodative, decompensating accommodative

•standard approach: residual distance deviation, can get undercorrections if use standard numbers

•augmented approach

•prism adaptation - pt can can be hiding/controlling phoria, use prisms until there is no further ET seen (pt will be fusing at this point)

•high ac/a

•can do overcorrections: and then cut plus up to 2.5 D

 

variable ET: prematurity, neurologic dz with dev delay, observe until more stable, surgical over corrections common

 

acquired non-accom et: later childhood or adulthood, no sig hyperopia, variable/intermittent becomes constant, rule out: tumors

 

divergence insufficiency: if have worse at distance than near, can be idiopathic primary strabismus, can be mild cn VI palsy, SCAN

 

CN VI palsy: true abduction deficit, large ET, trauma, increased ICP, papilledema

 

Type 1 Duane syndrome: abduction deficit out of proportion to ET (less ET than expected), fissure narrowing on adduction, parents think the nl eye is pathologic one