Free Space Testing

Maddox rod is what type of test?

subjective

If the Maddox rod is held so that the ridges run vertically, the light coming throught it will appear as a?

horizontal line

If the Maddox rod is held so that the ridges run horizontal, the light coming through will appear as a?

vertical line

What is a limitation of Maddox rod testing?

cannot b used to detect strabismus

What happens to the eye behind the Maddox rod?

goes to position of rest

If you put the Maddox rod over the right eye, which eye is fixating on the light and which eye is seeing the Line?

left eye is fixating on light

right eye is in position of rest

To test for horizontal deviation, which way does the patient hold the Maddox rod?

with the lines horizontally

If a person is holding the Maddox rod over their right eye, and they see the line through the light, what do you record?

ortho

If a person is holding the Maddox rod over their right eye and they see the line to the left, what deviation do they have?

exo deviation

If a person is holding the Maddox rod over their right eye and they see the line to the left, is their deviation crossed or uncrossed?

crossed diplopia

If a person is holding the Maddox rod over their right eye and they see the line to the left, are their eyes crossed or uncrossed?

uncrossed

If a person is holding the Maddox rod over their right eye and they see the line to the left, what prism do they need?

BI

If a person is holding the Maddox rod over their right eye and they see the line to the right, what deviation do they have?

eso

If a person is holding the Maddox rod over their right eye and they see the line to the right, is their deviation crossed or uncrossed?

uncrossed diplopia

If a person is holding the Maddox rod over their right eye and they see the line to the right, what prism do you need?

BO

If a person is holding the Maddox rod over their right eye and they see the line to the right, are their eyes crossed or uncrossed??

crossed

If you want to test for vertical deviations, which way is the Maddox rod held?

with the striations held vertically

If a person is holding the Maddox rod over their right eye and they see the line below, what deviation do they have?

right hyper deviation

If a person is holding the Maddox rod over their right eye and they see the line below, what prism do they need?

BD OD

If a person is holding the Maddox rod over their right eye and they see the line above, what deviation do they have?

right hypo deviation

If a person is holding the Maddox rod over their right eye and they see the line above, what prism do they need?

BU OD

Where do you document your Maddox rod findings?

ocular alignment section

What kind of test in modified thorington?

subjective phoria measurement

What is a downside to modified Thorington?

cannot distinguish strabismus

What eye is the Maddox rod over for modified Thorington??

right eye

If a person sees the line to the left during modified Thorington, what deviation do they have?

exophoria

If a person sees the line to the right during modified Thorington, what deviation do they have?

esophoria

If a person sees the line below during modified Thorington, what deviation do they have?

right hyperphoria

If a person sees the line above during modified Thorington, what deviation do they have?

right hypophoria

Where are the modified thorington results recorded?

ocular alignment

What are advantages to doing prism bar vergence ranges as opposed to phorometry vergence ranges?

allows patient to be in a more normal viewing environment with peripheral vision

allows examiner to observe patients eyes and document objective findings if suppression

When doing prism bar vergence ranges, what prism do you use first?

BI

What do you expect for distance BI prism bar vergence ranges?

no blur

What will you see if a patient reaches a break during BI prism bar vergence ranges?

eye under the prism will not continue to diverge as you increase prism

eye under the prism will drift to its phoric position

eyes will make saccades between 2 images

If you notice a break during BI prism bar vergence ranges, what do you look for as you decrease prism to record a recovery?

eye under the prism to make vergence movements toward the nose

What will you see if a patient reaches a break during BO prism bar vergence ranges?

eye under the prism will not continue to converge as you increase prism

eye under the prism will drift to its phoric position

eyes will make saccades between 2 images

Where do you record prism bar vergence ranges?

objective notes

What does the AC/A ratio allow us to do?

quantify the amount of convergence driven by accommodation

Why is the AC/A ratio important?

it can account for differences in phoria at distance and near

it can help guide treatments

If someone has a high AC/A ratio, how may their phoria at distance compare to near?

more eso at near/more exo at distance

If someone has a low AC/A ratio, how may their phoria at distance compare to near?

more exo at near/more eso at distance

When would you want to treat a near eso with bifocals or readers?

if they have a high AC/A ratio

When would you not want to treat a near eso with bifocals or readers?

if they have a low AC/A ratio

What is the AC/A equation?

AC/A= IPD (cm) + [(near phoria - distance phoria) x near distance (m)]

In the AC/A ratio, what sign is eso? exo?

eso is +

exo is -

What is a normal AC/A ratio?

4/1 to 6/1

What does an AC/A ratio of 4/1 mean?

for every diopter of accommodation, they eyes converge 4pd

What are two ways to test gradient AC/A?

using +1.00/-1.00 flippers + performing CT

behind phoropter using Von Graefe phorias and changing sphere power

When doing gradient AC/A, if the patient is looking through +1.00D lenses, do you expect them to be more or less eso than without them?

less eso

When doing gradient AC/A, if the patient is looking through +1.00D lenses, do you expect them to be more or less exo than without them?

more exo

When doing gradient AC/A, if the patient is looking through -1.00D lenses, do you expect them to be more or less exo than without them?

less exo

When doing gradient AC/A, if the patient is looking through -1.00D lenses, do you expect them to be more or less eso than without them?

more eso

How do you calculate the gradient AC/A ratio?

average of the two CT findings

Where do you put gradient AC/A ratio findings?

ocular alignment

What should you never get when performing gradient AC/A?

a negative AC/A

Who do we not do AC/A testing on?

presbyopes

What are the flaws of AC/A testing?

both assume full accommodative response to the demand

calculated dismisses proximal vergence