Management of Vertical Deviations Flashcards
What are the common signs of vertical strabismus?
Blurry vision, headaches, diplopia, dizziness/vertigo, car and motion sickness, abnormal head posture, vague vision complaints
Categorize vertical strabismus based on the magnitude of deviation. What are the different classifications?
- Small-Angle: 0.5 Δ to 5Δ
- Moderate-Angle: 6Δ to 15 Δ
- Large-Angle: ≥16 Δ
What is the difference between primary vertical strabismus and secondary vertical strabismus?
Primary: Deviation is always present; Secondary: Deviation only present when strabismic
Which type of vertical strabismus requires vertical prism to correct?
Primary Vertical strabismus
What are the characteristics of primary vertical strabismus?
- Noncomitant deviation is more common
- Must use vertical vergence to achieve fusion
- Associated phoria ≠ 0
- Vertical fixation disparity exists
What are the characteristics of secondary vertical strabismus?
- Deviation due to horizontal component
- If horizontal deviation is eliminated, vertical component disappears
- Associated phoria = 0; no vertical prism required
What is variable vertical strabismus?
Fluctuates in frequency and magnitude but direction remains the same; poor prognosis
What are dissociated vertical deviations?
Spontaneous drifting of either eye upward when the other eye is fixating; often associated with horizontal strabismus
Identify the prognostic factors for vertical strabismus.
- Magnitude: smaller angles are better
- Frequency: intermittent has better prognosis
- Comitancy: noncomitant deviations have worse prognosis
- Sensory anomalies: diplopia common
What is the general treatment strategy for vertical strabismus?
Objective is to stabilize binocular vision via prism, vision therapy, or surgery
What are the prism prescribing considerations?
- Neutralizing Prism: used when no vertical vergence ability
- Relieving Prism: based on residual vergence demand and fixation disparity
What is the active vision therapy sequence for hypertropia?
Train infravergence (Base-up)
What is the active vision therapy sequence for hypotropia?
Train supravergence (Base-down)
How would you set up a vectogram to train supravergence?
Move the vectogram slide seen by the hypo eye up
How would you set up a vectogram to train infravergence?
Move the vectogram slide seen by the hyper eye down
How would you set up a nonvariable tranaglyph to train supravergence?
The eye with the red filter sees the green target; green targets are up higher
What is the vertical fusion target method?
Backlit targets with red and green filters; small amount of inverse vertical prism is added
What do you expect the patient to see when suppressing compared to when fusing?
Initially see 6 boxes that split into 8; asked to fuse the 8 back into 6
What is the purpose of increasing the amount of prism slowly in vertical fusion targets?
To help the patient develop more control
