Transcript Principles of Investigation of Concomitant Strabismus

Classification of Concomitant
Deviations
Created on behalf of NHS NES as supplement to
workshops on binocular vision and additional
techniques.
Classification
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Eso / exo / hyper/ hypo
Constant / intermittent / latent
Accommodative element
Other near / distance difference
Manifest Esotropia
Manifest Esotropia
Primary
Secondary (due to loss
or impairment of VA,
usually in childhood
Constant
Accommodative
Element (larger Near)
Non-Accommodative
Consecutive
(previously exo)
Intermittent
Accommodative
Non-accommodative
(rare)
Infantile
Fully accommodative
(full control with gls)
Near Esotropia
(not affected by glasses
Acquired
Convergence Excess
(controlled in distance only
With glasses)
Distance Esotropia
Rare types (nystagmus
block, assoc with myopia
Cyclic Esotropia
Primary
ESOTROPIA
Constant
Accommodative
Element (larger Near)
•Hypermetropic
•Always manifest
•Angle smaller with glasses
•Angle smaller in distance
•Onset 6m – 3yrs
Primary
ESOTROPIA
Constant
Non-Accommodative
•Hypermetropia does not affect
angle
•Always manifest
•<10∆ difference Nr /Dist
•Onset often early but vague
Primary
ESOTROPIA
Constant
Non-Accommodative
•Onset before 6/12
•Large constant angle
Infantile
•Often alternate
•Associated with DVD and latent
nystagmus
Intermittent
ESOTROPIA
Accommodative
Fully
accommodative
•Hypermetropic +2.0 / +4.5
•Large manifest angle on
accommodation without glasses
•Fully controlled esophoria with
glasses
•Normal BSV (or microtropia) with
glasses
•Onset 18m – 4yrs
Intermittent
Accommodative
Convergence
Excess
ESOTROPIA
•Low hypermetropia +1.0 / +3.0
•Large manifest angle near &
distance without glasses
•Manifest esotropia with glasses for
near
•Fully controlled esophoria in
distance with glasses
•Normal BSV (or microtropia) with
glasses
•Onset 4-5
Intermittent
ESOTROPIA
Non-accommodative
(rare)
Near Esotropia
•Manifest esotropia near
•BSV Distance
•Not affected by plus lenses
Distance Esotropia •Manifest in distance only
•Lateral rectus weakness or post-op
Cyclic Esotropia
•Alternate day squint
Secondary
•Due to severe loss or impairment of
vision
•Esotropia - infancy onset
•Exotropia – onset after early
childhood
•Divergence with time in amblyopia
or absence of BV
Consecutive
•Eso when previously exo or vice
versa
•Post-operative Divergence with
time in amblyopia or absence of BV
•Divergence with time
Manifest Exotropia
Manifest Exotropia
Secondary (to loss
Of VA)
Primary
Constant
Early onset
Decompensated
intermittent
Consecutive
(previously eso)
Intermittent
Near exotropia
Distance exotropia
True
Non-specific
Simulated
Controlled with
Accommodation
Controlled with fusion
Primary
EXOTROPIA
Constant
Early onset
•Rare
•Suspect low VA
Decompensated
intermittent
•Often diagnosed from
history / photographs
•BSV may be
recoverable
Primary
Intermittent
Near exotropia
EXOTROPIA
•Often decompensated from
exophoria
•Manifest Near , controlled distance
•Older children /adults
•Check for dyslexia / stress
Non-specific
•Angle similar near /distance
•May be worse near or distance but
angle similar
Primary
EXOTROPIA
Intermittent
Distance exotropia
True
•Manifest exotropia 6m or Far
Distance
•Exophoria with normal BSV Near
•<10∆ change with +/- 3.00 or after
30 mins occlusion
Primary
EXOTROPIA
Intermittent
•Clinically similar to true distance
exotropia
Distance
exotropia
•Manifest distance, controlled near
Simulated
Controlled
with fusion
•Angle increases at 1/3m after 30
mins occlusion
Controlled with
Accommodation
•After occlusion angle inceases at
1/3m with +3.00 lenses
Heterophoria
Heterophoria
Esophoria
Exophoria
Hyperphoria
Near
Near
Concomitant
Distance
Distance
Incomitant
Non-specific
Non-specific
• Main difference between intermittent
heterotropia and heterophoria is
• Size of angle
• Fusion range
• Not cause