Exotropia Flashcards
What is the definition of an exotropia?
Manifest deviation of one or alternating eyes where there is an outward turn.
What is lateral incomitance?
Deviation is smaller on lateral gaze
What is primary constant exotropia?
Present under all conditions
When can the onset of primary constant exotropia be?
Early - leads to suppression and dense amblyopia
Decompensated EXOP or intermittent EXOT becomes constant - may get diplopia
What is the treatment for decompensating EXOP if it isn’t yet constant?
Reduce deviation via surgery to maintain binocularity (before decompensation/constant suppression)
What is primary intermittent distance exotropia?
Exotropia only present at distance
Ortho or EXOP at near
BSV at near, suppression at distance
Amblyopia unlikely
What is simulated distance exotropia?
Near angle appears smaller than distance due to fusion or accommodation controlling the near angle
How do you test for simulated distance exotropia?
Occlude 1 eye for 1 hour to disrupt fusion and re-measure the near angle using +3D to eliminate accommodation.
If angle larger than original CT at either distance: simulated
What is the management for primary constant exotropia?
Treat any amblyopia
Surgery
Botox
What is the management for primary intermittent distance exotropia?
Treat any amblyopia
Surgery to improve cosmesis or treat near decomp
Minus lens therapy
How does minus therapy work?
Induces accommodation and convergence to reduce exo size, restores BSV.
Teaches control by using accommodation.
How should minus therapy be used?
-2D over rx, FTW for 3/12
Reduce by 0.50 if controlling in distance
When is minus lens therapy successful?
When control is achieved with all extra minus removed
When would surgery be needed after trying minus lens therapy?
If can only control with some extra minus present
What is primary intermittent near exotropia?
Ortho or EXOP at distance
EXOT at near (suppression or diplopia)
What is the management for primary intermittent near exotropia?
Observation
Convergence exercises
Surgery (cosmetic/eliminate diplopia)
What is secondary exotropia?
Secondary to pathology causing poor vision in one eye, at birth or as an adult
What is the management for secondary exotropia?
Surgery
Botox
Occlusion therapy if strab amblyopia due to pathology
What is consecutive exotropia?
Px previously had esotropia
Can be post op
Can be due to divergence of eyes over time
What is the management for consecutive exotropia?
Observe
Botox if small angle or to ascertain best post op result
Prism to place back into suppression scotoma
Surgery if poor cosmesis or constant diplopia
