Management of Strab - Prism

Question 1

This type of prism completely eliminates vergence demand; Corrects for the entire deviation.

Answer 1

Corrective/Neutralizing Prism

Question 2

In what 3 situations are yoked prisms used?

Answer 2

1. Non-comitant deviation
2. Nystagmus
3. VF loss

Question 3

Who do we prescribe prism for?

Answer 3

Pxs with normal sensory fusion and inadequate motor fusion.

Question 4

What criteria do you follow to prescribe relieving prism?

Answer 4

• dissociated and associated prism criteria

Question 5

What test is used for dissociated prism criteria to prescribe relieving prism?

Answer 5

Alternate CT

Question 6

To determine the prism prescribed based on the disociated measure, what does the percentage criteria state?

Answer 6

Give percentage of the total dissociated deviation

Question 7

If an eso patient has a 6-20pd deviation, how much residual vergence demand should they be left with?

Answer 7

4-6pd

Question 8

This type of prism is the amount of prism that gives a fusion response. What test do you check with?

Answer 8

Fusion prism

- W4D, Stereo testing

Question 9

What type of strabismus can Sheard’s criterion be used on?

Answer 9

Intermittent exotrope

Question 10

This is the amount of prism needed to eliminate FD.

Answer 10

Associated Phoria

Question 11

What type of pxs do well with correction of associated phoria?

Answer 11

IXT or DIXT (distance intermittent exotrope)