General Management of Nonstrabismic BV Disorders (M1)

Question 1

What are the goals to achieve a functional cure of a BV disorder?

Answer 1

1. equal visual acuity in each eye
2. comfortable, single, binocular vision at all
   distances (far point to a normal near point of
   convergence)
3. stereopsis
4. normal ranges of motor fusion
5. corrective lenses & up to 5pd of prism may be worn

Question 2

What amount of anisometropia increases the risk of developing amblyopia?

Answer 2

0.50 D or greater

Question 3

After correcting refractive error in a patient, how long should you wait to have the patient come back in for a re evaluation?

Answer 3

4 to 6 weeks

Question 4

What are the BV disorders in which prescribing added plus is a possible management technique?

Answer 4

1. Accom dysfunction with low AA, high lag, difficulty with minus lenses
2. Accommodative insufficiency
3. Accommodative fatigue
4. Phoria/vergence anomalies (consider phoria and AC/A)
5. *Convergence excess
6. Basic esophoria

Question 5

What needs to be analyzed when prescribing added plus as a treatment for a BV disorder?

Answer 5

1. plus lens findings (VA, CT, etc)
2. BO findings
3. NRA and PRA (balance between two is one method)

Question 6

How much added plus is given to a nonpresbyope for a treatment of a BV disorder?

Answer 6

+2.50 t0 +3.00 is max

Question 7

What are the BV disorders in which prescribing added minus is a possible management technique?

Answer 7

1. high exophoria

2. divergence excess

Question 8

What aspects should be analyzed before prescribing an added minus to treat a BV disorder?

Answer 8

1. accom ability
2. age
3. divergence ability (BI)

Question 9

If prescribing added minus for fulltime wear how much minus is typically given?

Answer 9

1. usually between 1.00 and 2.00D
2. amount necessary to fuse
3. amount necessary to neutralize deviation

Question 10

Does over minus increase the risk for myopia?

Answer 10

no

Question 11

What are the BV disorders in which prescribing prism is a possible management technique?

Answer 11

1. low to normal AC/A
2. divergence insufficiency (most)
3. basic esophoria
4. primary vertical deviation

Question 12

What are the disadvantages to prescribing prism?

Answer 12

1. cannot address issues with accommodation or oculomotor ability or vergence facility
2. consider effect of suppression
3. cosmesis of RX, image distortion, weight of Rx
4. limit of prism in Rx
5. fresnel
6. “Dependence” on prism
7. prism adaptation (angle increases after wearing prism)

Question 13

How much prism can be ground into a lens? 1. How much can Fresnel provide? 2.

Answer 13

1. 5 to 7pd per lens

2. 40pd per lens

Question 14

Who is Saladin’s 1:1 rule indicated for? 1. What is the rule? 2

Answer 14

1. basic eso and divergence insufficiency

2. BO = (esophoria - BI recovery)/2

Question 15

What is Sheard’s criterion? 1. Are they better for eso or exo deviations? 2

Answer 15

1. compensating vergence must be 2x phoria

2. exo

Question 16

What is Percival’s criterion? 1. Are they better for eso or exo deviations? 2

Answer 16

1. patient should be in middle third of fusion range

2. eso

Question 17

How can horizontal prism be prescribed based on associated phoria findings?

Answer 17

amount of prism that reduces fixation disparity center of symmetry to 0

Question 18

What are the methods to prescribe for vertical prism?

Answer 18

1. associated phoria value
2. equate vergence ranges
3. vertical fixation disparity with horizontal deviation

Question 19

For what BV disorders is vision therapy the BEST option?

Answer 19

1. Convergence Insufficiency
2. Vergence Infacility
3. Accommodative Excess
4. Accommodative Infacility
5. Accommodative Insufficiency

Question 20

For what BV disorders is vision therapy a GOOD but not best option?

Answer 20

1. Convergence Excess
2. Basic Exo
   3, Basic Eso

Question 21

For what BV disorders is vision therapy not a great option because something else works so well option?

Answer 21

1. Divergence Insufficiency

2. Vertical