Accommodative Disorders

Question 1

How much accommodation is required for this patient to read at 25cm uncorrected?

OD: +1.00 DS
OS: +1.00 Ds

Answer 1

stimulus 1/.25=2D
accommodative demand=4D +1D=5D

5D

Question 2

what is the most likely diagnosis for a patient with a normal monocular PRA but a low binocular PRA?

Answer 2

low NFV

because binocular testing is abnormal and monocular is normal, this patient has a vergence issue.

Question 3

what is this patient’s near von graefe phoria when viewing through a +2.00D reading glasses?

OD: +1.00 Ds
OS: +1.00 Ds

Von Graefe
D: 2XP
N: 5XP

AC/A=4/1

Answer 3

9XP

for every 1D, the phoria changes by 4D
adding plus to an XP will make it worse, so putting 2D in front of them will take them from 5XP to 9XP

Question 4

accommodative infacility

Answer 4

characterized by a slow response to changes in accommodative stimulus. Patients will often complain about distance blur after near work. The NRA/PRA findings will likely be reduced, the patient will fail on plus AND minus lenses on monocular and binocular accommodative facility testing, and the AoA will be normal.

Question 5

failing the binocular accommodative facility

Answer 5

accommodative or vergence problem

Question 6

failing the monocular accommodative facility

Answer 6

accommodative

Question 7

if the patient fails binocular accommodative facility but passes on monocular, what is the problem?

Answer 7

vergence

Question 8

accommodative insufficiency

Answer 8

characterized by decreased AoA, receded NPC, fail with minus lenses on accommodative facility testing, and a low PRA value. The patient will complain of near asthenopia symptoms

Question 9

accommodative excess (Spasm)

Answer 9

characterized by a normal to high AoA, a lead of accommodation on MEM, low NRA, and fail with plus lenses on accommodative facility testing

Question 10

ill-sustained accommodation

Answer 10

characterized by normal AoA that fatigues easily after repeat testing. Patients also fail minus lenses during accommodative facility testing

Question 11

treatment for accommodative insufficiency

Answer 11

plus lenses followed by VT

Question 12

treatment for accommodative infacility

Answer 12

VT followed by plus lenses

Question 13

treatment for accommodative excess (spasm)

Answer 13

VT then plus lenses

Question 14

treatment for ill-sustained accommodation

Answer 14

plus lenses followed by VT

Question 15

VT therapy techniques for accommodative problems

Answer 15

red-red rock, Hart card distance to near accommodative rock, computer orthoptics, and binocular accommodative facility

Question 16

when is a patient comfortable viewing an object at near

Answer 16

when he is using half only half his AoA

Question 17

end point nystagmus

Answer 17

physiologic nystagmus and is not associated with oscillopsia. Small, intermittent, conjugate jerk nystagmus only apparent in extreme horizontal gazes (>30 degrees from midline). It is often worse when the patient is tired

Question 18

Jerk Nystagmus

Answer 18

characterized by a slow and fast phase. The slow phase (drift) represents the abnormality in fixation, and the fast phase is the corrected saccade that brings the fovea back on the target. Nystagmus is named for the direction of the fast phase

Question 19

pendular nystagmus

Answer 19

characterized by an even back and forth movement of the eyes

Question 20

null point

Answer 20

direction of gaze where the nystagmus has the lowest amp

Question 21

neutral point

Answer 21

direction of gaze where the nystagmus changes directions

Question 22

alexanders law

Answer 22

states that jerk nystagmus will increase in amplitude when the patient gazes in the direction of the fast phase

Question 23

physiologic nystagmus

Answer 23

end point
optokinetic
caloric
rotational

Question 24

optokinetic nystagmus

Answer 24

a conjugate jerk nystagmus responsible for maintaining the image of a moving object on the fovea when the head is stationary

Question 25

caloric nystagmus

Answer 25

a conjugate jerk nystagmus produced during caloric testing of the vestibular system

Question 26

rotational nystagmus

Answer 26

a conjugate jerk nystagmus produced during head/body rotation

Question 27

pathologic nystagmus

Answer 27

congenital (infantile)
latent
spasms nutans 
convergence-retraction syndrome
gaze-evoked potential

Question 28

characteristics of pathologic nystagmus

Answer 28

often dissociated and causes excessive drift that produces oscillopsia

Question 29

congenital (infantile) nystagmus

Answer 29

present at birth or before the age of 6; often binocular, horizontal, associated, and conjugate and may be pendular to jerk waveform. the nystagmus is often dampened by convergence and sleep and increased with fixation effort. Appx 40% of cases are due to a defect in the afferent visual pathway, resulting in poor image formation on the fovea and inadequate feedback to the oculomotor system to control fixation. The remaining 60% of cases are due to defects in the efferent motor pathway

aniridia, albinism, chromatopsia, ONH hypoplasia, optic atrophy, and congenital cataracts may lead to poor image formation and subsequent congenital nystagmus

Question 30

latent nystagmus

Answer 30

congenital, conjugate jerk nystagmus that increases in velocity and amp when one eye is covered. It is commonly associated with essential infantile ET and amblyopia

best to test VA under binocular conditions with one eye fogged rather than occluded. Vectographic or anaglyphic methods may also be used as they allow both eyes to stay open, thus reducing or eliminating latent nystagmus

Question 31

spasmus nutans

Answer 31

developed within 4-12m after birth and resolves after 2-8 years. Multiple family members are usually affected (there is no sex predilection). The nystagmus is usually disconjugate, high frequency, low amp, pendular waves with a horizontal and vertical component in most cases. It is often accompanied by head nodding and head turns. It is usually not associated with other ocular abnormalities and rarely has long term consequences.

Question 32

convergence retraction syndrome

Answer 32

characterized by an intermittent jerk nystagmus with a fast phase that causes convergence or retraction of the eyes. When the patient looks up, the eyes will slowly move down (slow phase), followed by a fast phase that causes convergence and/or retraction. This condition is often associated with dorsal midbrain syndromes

Question 33

Gaze-Evoked nystagmus

Answer 33

jerk nystagmus that only occurs at extreme gazes (usually horizontal or up gaze) and may be conjugate it disconjugate. Unlike physiological end point nystagmus, gaze evoked nystagmus occurs in the presence of other ocular motor abnormalities. It may develop secondary to drug use or posterior fossa disease

Question 34

see saw nystagmus

Answer 34

characterized by elevation and intorsion of one eye with depression and extortion of the fellow eye in a pendular or jerk waveform. It may be congenital or associated with parasellar lesions