General Management of Nonstrabismic BV Disorders (M1) Flashcards
What are the goals to achieve a functional cure of a BV disorder?
- equal visual acuity in each eye
- comfortable, single, binocular vision at all
distances (far point to a normal near point of
convergence) - stereopsis
- normal ranges of motor fusion
- corrective lenses & up to 5pd of prism may be worn
What amount of anisometropia increases the risk of developing amblyopia?
0.50 D or greater
After correcting refractive error in a patient, how long should you wait to have the patient come back in for a re evaluation?
4 to 6 weeks
What are the BV disorders in which prescribing added plus is a possible management technique?
- Accom dysfunction with low AA, high lag, difficulty with minus lenses
- Accommodative insufficiency
- Accommodative fatigue
- Phoria/vergence anomalies (consider phoria and AC/A)
- *Convergence excess
- Basic esophoria
What needs to be analyzed when prescribing added plus as a treatment for a BV disorder?
- plus lens findings (VA, CT, etc)
- BO findings
- NRA and PRA (balance between two is one method)
How much added plus is given to a nonpresbyope for a treatment of a BV disorder?
+2.50 t0 +3.00 is max
What are the BV disorders in which prescribing added minus is a possible management technique?
- high exophoria
2. divergence excess
What aspects should be analyzed before prescribing an added minus to treat a BV disorder?
- accom ability
- age
- divergence ability (BI)
If prescribing added minus for fulltime wear how much minus is typically given?
- usually between 1.00 and 2.00D
- amount necessary to fuse
- amount necessary to neutralize deviation
Does over minus increase the risk for myopia?
no
What are the BV disorders in which prescribing prism is a possible management technique?
- low to normal AC/A
- divergence insufficiency (most)
- basic esophoria
- primary vertical deviation
What are the disadvantages to prescribing prism?
- cannot address issues with accommodation or oculomotor ability or vergence facility
- consider effect of suppression
- cosmesis of RX, image distortion, weight of Rx
- limit of prism in Rx
- fresnel
- “Dependence” on prism
- prism adaptation (angle increases after wearing prism)
How much prism can be ground into a lens? 1. How much can Fresnel provide? 2.
- 5 to 7pd per lens
2. 40pd per lens
Who is Saladin’s 1:1 rule indicated for? 1. What is the rule? 2
- basic eso and divergence insufficiency
2. BO = (esophoria - BI recovery)/2
What is Sheard’s criterion? 1. Are they better for eso or exo deviations? 2
- compensating vergence must be 2x phoria
2. exo
What is Percival’s criterion? 1. Are they better for eso or exo deviations? 2
- patient should be in middle third of fusion range
2. eso
How can horizontal prism be prescribed based on associated phoria findings?
amount of prism that reduces fixation disparity center of symmetry to 0
What are the methods to prescribe for vertical prism?
- associated phoria value
- equate vergence ranges
- vertical fixation disparity with horizontal deviation
For what BV disorders is vision therapy the BEST option?
- Convergence Insufficiency
- Vergence Infacility
- Accommodative Excess
- Accommodative Infacility
- Accommodative Insufficiency
For what BV disorders is vision therapy a GOOD but not best option?
- Convergence Excess
- Basic Exo
3, Basic Eso
For what BV disorders is vision therapy not a great option because something else works so well option?
- Divergence Insufficiency
2. Vertical
